Orthopaedic Surgery - Knee Pain

Basics

Knee pain has a broad differential diagnosis and may arise from pathology within the knee itself or from disorders elsewhere that refer pain to the knee.

Pain may be diffuse or localized to a particular region.

In many patients, a careful history combined with a focused physical examination substantially narrows the diagnosis.

Knee pain can be broadly classified as:

Traumatic or acquired/nontraumatic.

Risk Factors

Factors that increase the likelihood of knee pain include:

Athletic activity, lower-extremity malalignment, ligamentous instability, obesity, and physical deconditioning or sedentary behavior.

Etiology

Major causes include:

Acute traumatic injury, repetitive overuse, degenerative disease, inflammatory disease, infection, and abnormalities involving structures around the knee.

Associated Conditions

Systemic disorders that may produce knee symptoms include:

Rheumatoid arthritis, gout, pseudogout, and other inflammatory arthropathies.

Increasing physical activity may also uncover previously asymptomatic structural abnormalities or overuse conditions.

Diagnosis

History

The history should clarify:

Onset, mechanism, pain location, swelling, locking, popping, instability, activity relationship, night pain, and functional limitations.

Symptoms such as difficulty climbing stairs or rising from a chair may point toward specific patterns of knee pathology.

General Symptoms

Common complaints include:

Swelling, locking, popping, giving way, difficulty using stairs, difficulty rising from a chair, and chronic pain that worsens with activity.

Patellofemoral Disorders

Patellofemoral Pain Syndrome

Patellofemoral pain commonly occurs in adolescents and young adults.

Pain is usually located at the anterior knee and is worsened by activities that increase patellofemoral joint loading, such as:

Climbing or descending stairs, squatting, prolonged sitting, and rising from a chair.

Crepitus may occur during knee motion.

Compression of the patella against the femoral trochlea may reproduce symptoms.

Patellofemoral pain is not synonymous with cartilage softening, although chondral abnormalities may coexist.

Patellar Subluxation and Dislocation

Patellar instability may be traumatic or related to underlying anatomy.

Predisposing factors can include:

Increased femoral anteversion, genu valgum, trochlear dysplasia, patella alta, abnormal rotational alignment, and increased lateralizing forces on the patella.

A positive J sign, in which the patella shifts laterally near terminal extension, may indicate abnormal tracking.

Articular Cartilage Injury

Articular cartilage injuries frequently follow trauma but may also result from chronic degenerative disease.

Pain is usually worsened by:

Weight bearing, impact activity, or repetitive loading.

Associated symptoms may include swelling, catching, or mechanical discomfort.

Meniscal Injury

Meniscal pathology may be:

Acute and traumatic or degenerative and related to chronic tissue deterioration.

Symptoms

Patients commonly report:

Joint-line pain, intermittent swelling, catching, locking, or giving way.

Effusion often develops gradually rather than immediately and may fluctuate with activity.

Location

Medial meniscal pathology causes medial joint-line pain, whereas lateral meniscal disease produces lateral joint-line symptoms.

Knee Arthritis

Arthritic symptoms typically have a gradual and progressive onset, although an acute osteochondral event may suddenly worsen a previously chronic condition.

Pain generally:

Increases with activity and improves with rest.

Patients may also develop pain:

At night after an active day or after prolonged periods of inactivity, such as a long car ride or bed rest.

Stiffness, swelling, crepitus, and loss of motion are common as arthritis progresses.

Anterior Cruciate Ligament Injury

The ACL primarily prevents anterior translation of the tibia relative to the femur and contributes importantly to rotational stability.

Mechanism

ACL injuries commonly occur through noncontact mechanisms such as:

Sudden deceleration, pivoting, cutting, or landing from a jump.

An audible or palpable pop and rapid swelling are common.

Reinjury Risk

A previous ACL tear increases the risk of:

Recurrent ACL injury in the reconstructed or previously injured knee and ACL injury in the contralateral knee.

Posterior Cruciate Ligament Injury

The PCL is the primary restraint to posterior translation of the tibia.

Mechanism

A classic mechanism is a direct blow to the anterior proximal tibia when the knee is flexed, such as a dashboard injury.

Symptoms

Pain and swelling occur acutely after injury and often improve over several weeks.

Chronic PCL deficiency may later contribute to:

Medial-compartment and patellofemoral degenerative symptoms.

Medial Collateral Ligament Injury

The MCL is the primary restraint to valgus stress.

Pain is typically located along the medial knee and may extend proximally or distally along the course of the ligament.

Mechanism

An isolated MCL injury commonly follows a direct blow to the lateral side of the knee, creating valgus stress.

MCL injury may also occur together with:

ACL tears, meniscal injury, or other multiligament trauma.

Lateral Collateral Ligament Injury

The LCL extends from the lateral femoral epicondyle to the fibular head and resists varus stress.

Isolated LCL injury is relatively uncommon.

It is often associated with:

Cruciate ligament or posterolateral corner injury.

Because of the proximity of the common peroneal nerve to the fibular head, motor and sensory function should be assessed carefully.

Quadriceps and Patellar Tendon Rupture

Disruption of either the quadriceps tendon or patellar tendon impairs the extensor mechanism.

Symptoms

Patients may have:

Anterior knee pain, effusion, inability to actively extend the knee, and inability to perform a straight-leg raise.

Examination

A palpable defect may be present.

Patellar position may also be abnormal:

Patella baja may occur with quadriceps tendon rupture, whereas patella alta may occur with patellar tendon rupture.

Mechanism

These injuries may follow:

Direct trauma or sudden forced knee flexion against a maximally contracting quadriceps muscle.

Bursitis and Tendinopathy

Inflammation or irritation may develop at bursae or tendon insertions around the knee.

The diagnosis is commonly suggested by localized tenderness directly over the involved structure.

Common Bursae

Common symptomatic locations include:

Prepatellar and pes anserine bursae.

Common Tendons

Tendinopathy frequently involves the:

Patellar tendon or distal quadriceps tendon.

Osteochondritis Dissecans

Osteochondritis dissecans commonly affects active children, adolescents, and young adults.

It involves a localized abnormality of the subchondral bone and overlying articular cartilage.

Symptoms

Patients may develop:

Activity-related pain, effusion, localized tenderness, catching, or locking.

Mechanical symptoms become more likely if an unstable fragment separates and becomes a loose body.

Osgood–Schlatter Disease

Osgood–Schlatter disease is a traction apophysitis of the tibial tubercle.

It is common in active growing children and adolescents.

Repetitive traction from the patellar tendon produces:

Pain, swelling, and tenderness over the tibial tubercle.

Symptoms are aggravated by running, jumping, kneeling, and resisted extension.

Baker Cyst

A Baker or popliteal cyst is a distension of the posterior knee capsule or bursa that often communicates with the knee joint.

It is frequently associated with intra-articular pathology, including:

Meniscal tears, arthritis, and chronic synovitis.

Presentation

Patients may complain of:

A posterior knee mass, fullness, or pressure.

The underlying intra-articular disease may itself produce few symptoms.

Fracture

A fracture around the knee must be considered after significant trauma.

Potential sites include:

Distal femur, proximal tibia, tibial plateau, and patella.

Plain radiographs are usually the initial diagnostic study.

Bone Tumor

Bone tumors are uncommon but should remain in the differential diagnosis, especially when pain is:

Persistent, progressive, present at night, unrelated to activity, or associated with constitutional symptoms.

Symptoms

Patients may describe:

Deep, dull, aching pain that gradually becomes constant.

Additional findings may include:

Swelling, reduced function, fatigue, low-grade fever, weight loss, or a pathologic fracture.

Physical Examination

Palpation

Palpate the knee for:

Effusion, localized swelling, warmth, and focal tenderness.

Joint-Line Tenderness

Medial or lateral joint-line tenderness may suggest:

Meniscal pathology or compartmental arthritis.

Other Tender Areas

Palpate the:

Pes anserine bursa, patellar tendon, quadriceps tendon, patella, collateral ligaments, and other symptomatic structures.

Range of Motion

Compare the affected knee with the contralateral side.

Assess:

Flexion, extension, presence of contracture, pain, crepitus, and extension lag.

Patellar Tracking

Observe the patella as the knee moves from flexion into extension.

Abnormal lateral translation or a J sign may indicate patellar maltracking or instability.

Ligament Stability

Assess the major ligament groups systematically.

MCL

Use valgus stress testing.

LCL

Use varus stress testing.

ACL

Use the:

Lachman test and anterior drawer test.

The Lachman test is generally the more sensitive examination maneuver.

PCL

Assess with:

Posterior drawer, posterior sag, and quadriceps active testing.

Laboratory Tests

Laboratory testing should be guided by the suspected diagnosis rather than ordered routinely for all patients with knee pain.

Suspected Septic Arthritis

Appropriate studies may include:

Complete blood count with differential, ESR, CRP, blood cultures when indicated, and urgent synovial fluid analysis.

Suspected Inflammatory Arthritis

Targeted evaluation may include:

Rheumatoid factor, anti-CCP antibodies, ANA, ESR, CRP, and other tests depending on the clinical context.

Suspected Gout

Serum uric acid may be obtained, although a normal value does not exclude an acute gout attack.

Definitive diagnosis is made by synovial crystal analysis.

Imaging

Plain Radiographs

Radiographs are usually the first imaging study when structural pathology is suspected.

Useful views include:

Weight-bearing AP or PA, lateral, and tangential patellofemoral views such as Merchant or sunrise views.

Depending on the clinical question, additional views may be obtained.

MRI

MRI is useful for evaluating:

Meniscal tears, ligament injuries, articular cartilage lesions, osteochondral abnormalities, synovial proliferative disorders, tumors, and osteonecrosis.

MRI should be obtained when the result is expected to alter diagnosis or management.

Arthrocentesis

Joint aspiration can provide critical diagnostic information in a patient with an unexplained effusion.

Septic Arthritis

Synovial findings may include:

High white blood cell count with neutrophil predominance and positive bacterial culture.

A count above approximately 50,000 cells/mm³ strongly raises suspicion, although infection may occur at lower values and inflammatory arthritis may occasionally produce similarly high counts.

Gout

Gout is characterized by:

Monosodium urate crystals that are needle-shaped and strongly negatively birefringent under polarized light.

Synovial leukocytosis is common and may occasionally be substantial.

Pseudogout

Calcium pyrophosphate deposition disease demonstrates:

Rhomboid-shaped, weakly positively birefringent crystals.

Fat Droplets

Fat droplets within aspirated joint fluid may suggest an intra-articular fracture with marrow communication.

Pathological Findings

Pathologic findings vary entirely according to the underlying disorder.

Differential Diagnosis

Common diagnostic categories include:

Patellofemoral disorders

Articular cartilage and osteochondral injuries

Meniscal disease

Osteoarthritis and inflammatory arthritis

Ligament tears

Tendinopathy and tendon rupture

Osteochondritis dissecans

Osgood–Schlatter disease

Baker cyst

Gout and pseudogout

Fracture

Tumor

The diagnosis is established by integrating the history, pain location, physical examination, laboratory studies when appropriate, and imaging.

Clinical Clues From History and Pain Location

Certain patterns are particularly useful.

Locking with medial or lateral joint-line pain suggests a meniscal tear.

A pop during a sudden pivot followed by swelling suggests ACL injury.

Anterior knee pain with stairs or rising from a chair suggests patellofemoral pathology.

A direct blow to the proximal tibia with the knee flexed suggests PCL injury.

Side impact with medial or lateral pain suggests collateral ligament injury.

Chronic activity-related pain with stiffness suggests arthritis or another degenerative process.

Treatment

Treatment depends on the underlying diagnosis.

Patellofemoral Pain

Initial treatment commonly includes:

Activity modification, NSAIDs or other simple analgesia when appropriate, and exercise-based physical therapy.

Therapy should focus on:

Quadriceps strength, hip and core strength, flexibility, and correction of movement patterns.

Patellar Instability

Many first-time or mild cases can be managed with:

Physical therapy, activity modification, and selected patellar-stabilizing braces.

Recurrent instability or major structural abnormalities may require surgical evaluation.

Arthritis

Initial nonoperative management may include:

Analgesics, NSAIDs, activity modification, weight reduction when appropriate, physical therapy, assistive devices, unloader bracing for selected unicompartmental disease, and intra-articular injections.

Bursitis and Tendinopathy

Treatment generally consists of:

Activity modification, ice, topical or oral analgesic therapy, and correction of contributing mechanical factors.

Routine aspiration of uncomplicated bursitis is usually avoided unless infection or another specific indication is suspected.

Osgood–Schlatter Disease

Treatment includes:

Relative rest, activity modification, stretching, and anti-inflammatory medication when appropriate.

Most cases resolve as skeletal maturity is reached.

Ligament and Meniscal Injuries

Initial management may include:

Protected weight bearing, controlled range of motion, ice, analgesia, and orthopaedic or sports-medicine referral when indicated.

Treatment depends on:

Patient age, instability, tear pattern, activity level, associated injuries, and chronicity.

Physical Therapy

Physical therapy is highly useful for many causes of knee pain.

Common goals include:

Restoring range of motion, strengthening the quadriceps and hamstrings, improving hip and core strength, increasing flexibility, correcting gait and movement mechanics, and restoring proprioception.

Adjunctive modalities may include:

Cryotherapy and selected electrical stimulation.

Exercise-based rehabilitation is generally the core of treatment.

Medication

Common medication options include:

NSAIDs and acetaminophen.

Long-term opioid therapy generally should be avoided for routine musculoskeletal knee pain.

Intra-Articular Therapy

For selected patients with arthritis, intra-articular treatment may include:

Corticosteroid injections and, in some settings, hyaluronic acid products.

Expected benefit varies according to the underlying diagnosis and patient factors.

Surgery

Knee surgery can broadly be grouped into three categories.

Arthritis Surgery

Potential procedures include:

Osteotomy, unicompartmental knee arthroplasty, and total knee arthroplasty.

Arthroscopic debridement has a limited role in routine degenerative osteoarthritis and is generally reserved for selected mechanical pathology rather than arthritis alone.

Sports Medicine Procedures

These include:

Arthroscopic meniscal treatment, ligament reconstruction, cartilage procedures, and patellar stabilization or realignment surgery.

Trauma Surgery

Trauma procedures include:

Internal fixation of fractures and repair of quadriceps or patellar tendon rupture.

Follow-Up

Prognosis

The prognosis is generally excellent when:

The underlying diagnosis is accurately identified and appropriate operative or nonoperative treatment is provided.

Outcome depends on the severity and chronicity of the underlying disorder.

Complications

Potential consequences of inadequately treated knee pathology include:

Loss of motion, loss of function, impaired weight bearing, persistent instability, progressive arthritis, and chronic pain.

Patient Monitoring

Patients should be reassessed according to the severity of the underlying diagnosis.

For many musculoskeletal conditions, follow-up at approximately 4–6 week intervals is appropriate until:

Range of motion, strength, stability, and function have substantially recovered.

Persistent swelling, mechanical locking, night pain, fever, progressive weakness, or failure to improve should prompt reconsideration of the diagnosis and further investigation.

Orthopaedic Surgery - Knee Injection

Basics

Knee aspiration and intra-articular injection are commonly performed for both diagnostic and therapeutic purposes.

Aspiration removes fluid from the knee joint, whereas injection introduces medication or another solution into the joint.

Indications for Knee Injection

Injection may be performed for:

Delivery of medication for treatment of knee pain or inflammation

Administration of local anesthetic to facilitate diagnostic examination

Selected diagnostic procedures involving intra-articular fluid administration

Historically, saline load testing was used to evaluate whether a traumatic periarticular wound communicated with the knee joint, although other imaging-based approaches may also be used depending on the clinical setting.

Indications for Knee Aspiration

Arthrocentesis may be indicated for:

Large symptomatic effusion

Large hemarthrosis

Evaluation for septic arthritis

Investigation of inflammatory synovitis or arthritis

Aspiration may also relieve pain and improve motion when a tense effusion is present.

Equipment

Typical equipment includes:

Antiseptic skin-preparation solution

Sterile gloves

Large-bore needle, commonly approximately 18 gauge

20–60 mL syringes

Additional supplies may include:

Sterile drapes, local anesthetic, dressings, specimen containers, and ultrasound equipment when needed.

Technique

Several approaches to the knee joint are possible.

The superolateral approach is particularly reliable for aspiration of a large effusion.

Patient Position

Place the patient supine with the knee fully extended.

The quadriceps should be relaxed to facilitate access to the suprapatellar pouch.

Sterile Preparation

Perform a wide sterile preparation of the knee.

A broad preparation is useful because manipulation of the patella or knee may be required during the procedure.

Superolateral Entry Site

Identify a point approximately:

1 cm proximal to the superior pole of the patella and 1 cm lateral to its lateral border.

This provides access to the suprapatellar pouch.

Needle Insertion

Advance the needle through the:

Skin, subcutaneous tissues, and lateral retinaculum

toward the suprapatellar pouch between the quadriceps tendon and distal femur.

Once the needle enters the joint, apply gentle suction with the syringe.

Aspiration

Withdraw as much joint fluid as required.

The aspirated fluid should be inspected for:

Color, clarity, viscosity, turbidity, and the presence of blood or purulence.

Large Effusions

If the syringe becomes full before the joint has been adequately decompressed, the syringe can be exchanged while the needle remains within the joint.

A clamp or other sterile stabilization method can be used to prevent movement of the needle during syringe exchange.

Aspiration continues until sufficient fluid has been removed.

Completion of Aspiration

After aspiration is complete:

Remove the needle and apply a sterile dressing or adhesive bandage.

When clinically indicated, synovial fluid should be sent promptly for laboratory analysis.

Synovial Fluid Analysis

Depending on the clinical question, studies may include:

Cell count with differential, Gram stain, bacterial culture, crystal analysis, and other targeted tests.

When septic arthritis is suspected, specimens should be obtained before intra-articular corticosteroid administration.

Therapeutic Injection After Aspiration

If an intra-articular medication is to be administered, the aspiration syringe may be exchanged for the medication syringe while maintaining sterile needle position.

The medication should enter the joint with minimal resistance when the needle is correctly positioned.

Marked resistance should prompt reassessment of needle position rather than forceful injection.

Technical Pearls

Wide Sterile Preparation

Preparing a large area allows the examiner to manipulate the patella or reposition the knee without contaminating the sterile field.

Large-Bore Needle

Synovium, fibrin, or clotted blood may obstruct a smaller needle.

An 18-gauge needle is often useful when aspirating thick fluid or hemarthrosis.

Local Anesthesia

Pain at the puncture site can be reduced with:

A small amount of infiltrated lidocaine or a topical vapocoolant such as ethyl chloride.

Ultrasound Guidance

Ultrasound can improve confidence in needle placement and may be especially helpful in:

Obese patients, small or loculated effusions, distorted anatomy, or previously unsuccessful aspiration attempts.

It also allows visualization of the effusion and surrounding soft tissues.

Contraindication: Overlying Cellulitis

A knee should not be aspirated or injected through infected or cellulitic skin because the needle may introduce organisms into the joint.

An alternative entry site or another diagnostic strategy should be used.

Medications

Lidocaine

Lidocaine may be used as a local or intra-articular anesthetic.

Diagnostic anesthetic injection can temporarily decrease pain and permit a more complete knee examination.

Lidocaine may also be combined with corticosteroid to reduce injection discomfort.

Bupivacaine

Bupivacaine provides a longer duration of local anesthesia than lidocaine.

However, concerns exist regarding dose-dependent chondrotoxicity, particularly with prolonged or continuous intra-articular exposure.

For this reason, intra-articular local anesthetics should be used judiciously.

Corticosteroid

Intra-articular corticosteroid may provide temporary relief of inflammatory knee pain.

It is essential to exclude joint infection before administration.

Typical Preparation

A commonly used preparation is triamcinolone acetonide, historically given as approximately:

40 mg, or 1 mL of a 40 mg/mL preparation, depending on the indication and clinical protocol.

It may be combined with a small amount of local anesthetic.

Corticosteroid Adverse Effects

The most common short-term adverse event is a post-injection flare, consisting of temporary worsening of pain and inflammation after the procedure.

Patients should be warned about this possibility.

Other potential complications include:

Skin depigmentation, subcutaneous fat atrophy, transient hyperglycemia, infection, and, with repeated exposure, concern for cartilage effects.

Hyaluronic Acid

Hyaluronic acid injections have been used for symptomatic treatment of mild to moderate knee osteoarthritis.

Potential benefits include:

Reduction in pain, decreased stiffness, and improvement in function in selected patients.

The magnitude and consistency of benefit vary among patients and products.

Administration

Hyaluronic acid may be given as:

A single injection or as a series of injections, depending on the preparation used.

Complications

Potential complications of knee aspiration or injection include:

Pain, bleeding, hemarthrosis, infection, vasovagal reaction, damage to adjacent structures, post-injection flare, and failure to enter the joint.

Sterile technique and careful anatomic localization reduce these risks.

Patient Monitoring

After injection or aspiration, the patient should be instructed to monitor for:

Increasing pain, progressive swelling, erythema, fever, drainage, or inability to bear weight.

These findings may indicate infection or another significant complication and warrant prompt reassessment.

Patients receiving therapeutic injections should also be counseled regarding the expected duration of symptom relief and the need for further evaluation if symptoms persist or recur.

Orthopaedic Surgery - Knee Examination in the Child

Basics

Examination of the pediatric knee must take the child’s age, stage of skeletal development, normal alignment changes, and age-specific disorders into account.

The differential diagnosis differs considerably between infants, young children, and adolescents. Normal developmental variants must be distinguished from pathologic deformities, infection, trauma, inflammatory disease, and tumors.

Because pain from the hip frequently presents as knee pain, evaluation of the pediatric knee should routinely include assessment of the hip and entire lower extremity.

Congenital Hyperextension and Dislocation of the Knee

Congenital knee hyperextension represents a spectrum ranging from simple hyperextension to fixed anterior dislocation of the tibia relative to the femur.

The deformity is evident at birth.

A flexible hyperextended knee may resolve spontaneously or respond to gentle conservative treatment, whereas a fixed congenital knee dislocation often requires more intensive treatment and occasionally surgery.

Blount Disease

Blount disease, or tibia vara, results from abnormal development of the medial proximal tibial physis, producing progressive bowing of the lower extremity.

It occurs in infantile and adolescent forms.

Normal Varus-Valgus Development

Normal coronal alignment changes with growth.

At birth, children normally have approximately 10–15° of genu varum.

By approximately 12–18 months, the legs become nearly neutral.

Between approximately 3 and 5 years, physiologic valgus reaches its maximum, often around 10–15°.

During later childhood and early adolescence, valgus gradually decreases toward the adult range of approximately 5–10°.

Persistent or progressive deformity outside this expected pattern should be investigated.

Infantile Tibia Vara

Infantile Blount disease usually presents between approximately 2 and 4 years of age.

The child commonly has painless, progressive bowing of the legs.

Adolescent Tibia Vara

Adolescent Blount disease usually becomes apparent after approximately 9–10 years of age.

It is increasingly associated with obesity and mechanical overload of the proximal tibial growth plate.

Discoid Meniscus

A discoid meniscus is a congenital abnormality in which the meniscus, usually the lateral meniscus, remains abnormally broad and disc-shaped.

This morphology makes it more susceptible to:

Tearing, instability, snapping, pain, and mechanical symptoms.

Septic Arthritis of the Knee

Septic arthritis is a pyogenic infection of the knee joint.

Approximately two-thirds of pediatric cases historically occur before 3 years of age.

Affected children typically appear acutely ill and may present with:

Fever, joint swelling, severe pain, restricted motion, and refusal to bear weight.

Popliteal Cyst

A popliteal or Baker cyst arises from the posterior aspect of the knee.

In children, it commonly presents as:

An asymptomatic or minimally painful posteromedial mass at the popliteal crease.

Tibial Spine Fracture

A tibial spine fracture is an avulsion fracture involving the tibial insertion of the ACL.

It commonly occurs after:

Bicycle falls, sporting injuries, or other indirect twisting trauma.

In skeletally immature patients, the tibial spine may fail before the ACL itself ruptures.

Genu Valgum

Physiologic genu valgum normally decreases after early childhood.

Valgus deformity that becomes progressively greater after approximately 7 years of age should not be considered physiologic.

Significant deformity may be associated with knee pain and abnormal mechanical loading.

Juvenile Idiopathic Arthritis

Juvenile idiopathic arthritis may involve the knee and produce:

Persistent swelling, warmth, stiffness, synovitis, reduced motion, and sometimes pain.

Substantial effusion may be present despite relatively mild discomfort.

Osgood–Schlatter Disease

Osgood–Schlatter disease is a traction apophysitis of the tibial tubercle.

It occurs most commonly during rapid skeletal growth, usually between approximately 9 and 14 years of age.

Typical symptoms include:

Pain and tenderness over the tibial tubercle, aggravated by running, jumping, kneeling, and resisted knee extension.

Osteochondritis Dissecans

Osteochondritis dissecans is an osteochondral disorder in which a segment of subchondral bone and its overlying cartilage becomes abnormal.

The precise cause is uncertain.

The classic juvenile lesion occurs along the lateral aspect of the medial femoral condyle.

Iliotibial Band Syndrome

Iliotibial band syndrome is a common cause of lateral knee pain in athletes.

It is an overuse condition related to repetitive irritation of the iliotibial band near the lateral femoral epicondyle.

Pain is usually aggravated by running, cycling, or repetitive flexion and extension.

ACL Injury

ACL injuries occur through two broad mechanisms.

Younger children may sustain injury after direct trauma, whereas older children and adolescents more commonly experience:

Twisting, pivoting, or other indirect noncontact mechanisms.

Lyme Disease

Early Lyme disease may present with:

Fever and migratory arthralgia, often with little or no joint swelling.

Lyme Arthritis

Late Lyme arthritis may occur months or years after the initial infection.

The knee is commonly affected and may demonstrate:

A large but relatively painless effusion with low-grade inflammatory synovitis.

Slipped Capital Femoral Epiphysis

SCFE is an important cause of referred knee pain.

It typically affects an overweight child or adolescent, often between approximately 6 and 14 years of age.

Because knee pain may be the principal complaint, SCFE can be missed if the hip is not examined.

Unexplained knee pain associated with limp or limited hip rotation should therefore prompt hip examination and appropriate hip radiographs.

Diagnosis

History

The history should characterize:

Onset, duration, pain location, trauma, activity relationship, swelling, mechanical symptoms, instability, constitutional symptoms, and night pain.

Acute Pain

Acute pediatric knee pain may result from:

Ligament injury, meniscal tear, fracture, patellar instability, or septic arthritis.

Chronic Pain

Chronic or recurrent symptoms may occur with:

Genu valgum, juvenile idiopathic arthritis, Osgood–Schlatter disease, Sinding-Larsen–Johansson syndrome, osteochondritis dissecans, iliotibial band syndrome, Lyme disease, tendinopathy, or neoplasm.

Pain Location

The location of pain provides useful diagnostic information.

Anterior Knee Pain

Possible causes include:

Patellofemoral pain syndrome, patellar maltracking, symptomatic plica, and symptomatic bipartite patella.

Lateral Knee Pain

Pain over the lateral femoral epicondyle, particularly in an athlete, is suggestive of:

Iliotibial band syndrome.

Tibial Tubercle Pain

Pain localized to the tibial tubercle is typical of:

Osgood–Schlatter disease.

Inferior Patellar Pain

Pain at the inferior pole of the patella may represent:

Sinding-Larsen–Johansson syndrome.

Night Pain

Persistent or progressive night pain should raise concern for serious pathology, including:

Osteosarcoma, Ewing sarcoma, infection, or another neoplasm.

Swelling

Acute Swelling

Acute effusion may accompany:

Ligament tears, meniscal injuries, fractures, patellar dislocation, or septic arthritis.

Chronic Swelling

Persistent swelling may be associated with:

Juvenile idiopathic arthritis, Lyme arthritis, chronic synovitis, osteochondral disease, or neoplasm.

Mechanical Symptoms

Catching or Locking

These symptoms suggest:

Meniscal tearing, articular cartilage injury, or loose bodies, including fragments associated with osteochondritis dissecans.

Giving Way

A sensation that the knee is buckling or coming apart may indicate significant ligamentous instability.

Physical Examination

General Principles

The entire lower extremity should be exposed sufficiently to evaluate:

Alignment, swelling, muscle bulk, deformity, and gait.

When palpating, begin with the normal knee for comparison and to help relax the child.

Nonpainful examination maneuvers should be performed before potentially painful tests.

Inspection

Anterior View

Assess for:

Genu varum, genu valgum, effusion, patellar position, swelling, and muscular asymmetry.

In adolescence, normal standing alignment usually demonstrates mild valgus of approximately 5–10°.

Lateral View

Look for:

Flexion contracture, inability to reach full extension, or excessive hyperextension such as genu recurvatum.

Tibial Tuberosities

Compare the position and prominence of the tibial tubercles.

Asymmetry may suggest rotational deformity or developmental abnormality.

Palpation

Assess for warmth and tenderness along the:

Medial and lateral joint lines, MCL, LCL, patella, quadriceps tendon, patellar tendon, femoral condyles, tibial condyles, and tibial tubercle.

Localized tenderness should be correlated with the underlying anatomy.

Hip Examination

Because hip disorders may present entirely as knee pain, hip range of motion should be evaluated in every child with unexplained knee symptoms.

Assess:

Flexion, extension, abduction, internal rotation, and external rotation.

Restricted internal rotation or obligatory external rotation during flexion should raise concern for hip pathology such as SCFE.

Assessment for Knee Effusion

A large effusion obscures the normal contours of the knee and may make the patella ballotable.

Large effusions can occur with:

Hemarthrosis, septic arthritis, inflammatory arthritis, and synovitis.

A smaller effusion may cause only subtle loss of normal landmarks.

Blot and milking tests can help identify low-volume joint fluid.

Patellar Examination

Patellar Inhibition Test

This test assesses whether anterior knee pain is arising from the patellofemoral articulation.

With the patient supine and the knee extended, ask the child to perform a straight-leg raise while the examiner restricts superior movement of the patella.

Reproduction of anterior knee pain suggests patellofemoral pathology.

J Sign

The J sign evaluates patellar tracking.

Observe the patella while the patient actively extends the knee.

Normally, the patella tracks within the femoral trochlea.

A positive J sign occurs when the patella moves abruptly laterally near terminal extension, producing an upside-down J-shaped path.

This finding suggests:

Lateral patellar maltracking or instability.

Meniscal Examination

McMurray Test

The McMurray test is used to evaluate meniscal tears.

Medial Meniscus

Flex the hip and knee maximally.

Externally rotate the tibia and apply a valgus force while gradually extending the knee.

A painful palpable click or snap along the medial joint line suggests medial meniscal injury.

Lateral Meniscus

Flex the knee, internally rotate the tibia, and apply a varus force while extending the knee.

A painful click along the lateral joint line suggests lateral meniscal pathology.

Range of Motion

Flexion

Normal knee flexion is approximately 130–140°.

The patient can be examined sitting, supine, or prone.

Extension

Children commonly reach neutral extension and may demonstrate approximately 5° of physiologic hyperextension.

Comparison with the opposite knee is important.

Ober Test

The Ober test evaluates iliotibial band flexibility.

Technique

The patient lies on the unaffected side.

The pelvis is stabilized while the symptomatic hip is abducted and extended with the knee flexed.

The examiner then allows the thigh to fall into adduction.

Positive Test

If the thigh remains elevated and does not fall toward the examination table, the test suggests iliotibial band tightness.

This may support a diagnosis of iliotibial band syndrome.

Stability Testing

Anterior-posterior stability is provided predominantly by the:

ACL and PCL.

Mediolateral stability is provided primarily by the:

MCL and LCL.

ACL

The ACL is evaluated with:

Lachman and anterior drawer tests.

PCL

The PCL is evaluated with:

Posterior drawer and posterior sag tests.

Collateral Ligaments

Varus and valgus stress testing assesses the:

LCL and MCL, respectively.

Pediatric ligamentous laxity varies, so comparison with the opposite knee is especially useful.

Neurovascular Examination

A neurovascular examination is particularly important after acute injury.

Sensory Testing

Test sensation in the distributions of the:

Common peroneal, superficial peroneal, deep peroneal, and tibial nerves.

Motor Testing

Apply resistance while the patient:

Dorsiflexes and plantarflexes the ankle, inverts and everts the foot, and extends and flexes the great toe.

Pulses

Palpate the:

Popliteal, dorsalis pedis, and posterior tibial pulses.

Capillary refill and limb temperature should also be assessed if vascular injury is a concern.

Imaging

Standard Knee Radiographs

Common views include:

AP, lateral, tunnel, and patellofemoral axial views.

The specific views obtained should be tailored to the suspected diagnosis.

Skyline / Merchant View

The skyline or Merchant view is an axial image of the patellofemoral joint, usually obtained with approximately 35–45° of knee flexion.

It helps evaluate:

Patellar position, trochlear morphology, patellofemoral congruence, and osteochondral abnormalities.

Tunnel View

A flexed-knee AP or tunnel view is particularly helpful for identifying:

Osteochondritis dissecans lesions of the femoral condyles.

Standing Long-Leg Radiographs

A standing radiograph extending from the:

Hips through the knees to the ankles

is used to evaluate the mechanical axis and coronal alignment.

This is particularly useful for:

Blount disease and genu valgum.

MRI

MRI is the most useful advanced imaging modality for:

Meniscal tears, ligament injury, articular cartilage pathology, osteochondral lesions, and soft-tissue masses.

Congenital Knee Dislocation Imaging

Plain radiographs help distinguish:

Flexible hyperextension from fixed anterior tibial dislocation relative to the distal femur.

Blount Disease and Genu Valgum Imaging

The preferred study is an:

AP standing long-cassette radiograph of both lower extremities including the hips, knees, and ankles.

This demonstrates:

Mechanical-axis deviation, proximal tibial deformity, and abnormalities in joint orientation.

Discoid Meniscus Imaging

MRI is the most useful examination.

It can define:

Meniscal shape, thickness, tearing, and instability.

Plain radiographs may occasionally show:

Widening of the lateral joint space or squaring of the lateral femoral condyle.

Septic Arthritis Imaging

Early plain radiographs are often nonspecific and may show only:

Soft-tissue swelling or apparent joint-space widening caused by effusion.

Ultrasound may demonstrate an effusion and can guide aspiration.

MRI is useful when adjacent osteomyelitis or deeper infection is suspected.

Popliteal Cyst Imaging

Plain radiographs are generally normal and are usually needed only when pain or another diagnosis requires exclusion.

Ultrasound

Ultrasound can confirm the fluid-filled nature of the cyst and distinguish it from a solid soft-tissue mass.

MRI

MRI may be obtained when ultrasound findings are atypical or the lesion does not appear to be a simple homogeneous cyst.

Tibial Spine Fracture Imaging

AP and lateral radiographs are essential.

The lateral view is particularly useful for assessing the degree of displacement of the tibial spine fragment.

Juvenile Idiopathic Arthritis Imaging

Radiographs may remain normal early in the disease.

With progression, findings can include:

Periarticular osteopenia, soft-tissue swelling, synovial hypertrophy, effusion, and eventually joint-space loss or erosive changes.

Osgood–Schlatter Disease

Diagnosis is usually clinical.

Radiographs may demonstrate:

Irregularity, fragmentation, or prominence of the tibial tubercle apophysis.

Routine radiographs may be unnecessary in a typical bilateral presentation.

Unilateral, atypical, or severe symptoms should prompt imaging to exclude:

Neoplasm, infection, or fracture.

Sinding-Larsen–Johansson Syndrome

Radiographs may demonstrate irregularity or ossification at the inferior pole of the patella.

Diagnosis is primarily clinical.

Osteochondritis Dissecans Imaging

Plain radiographs may show:

A subchondral bone fragment separated from adjacent bone by a radiolucent line.

The classic lesion occurs along the lateral aspect of the medial femoral condyle, commonly involving its posterior portion.

Recommended views include:

AP, lateral, and tunnel radiographs.

MRI

MRI helps determine:

Lesion size, cartilage involvement, stability, and surrounding bone changes.

Iliotibial Band Syndrome Imaging

Routine radiographs are generally unnecessary because the diagnosis is usually based on history and examination.

Imaging is reserved for atypical cases or when another diagnosis is suspected.

ACL Injury Imaging

ACL injury is diagnosed primarily by physical examination.

Plain radiographs should nevertheless be obtained in children with significant suspected ligament trauma because they may reveal:

Tibial spine avulsion, fracture, osteochondral injury, or physeal injury.

MRI

MRI is useful when:

The examination is difficult to interpret, effusion persists, motion does not recover, or associated meniscal, ligamentous, or cartilage injuries require definition.

Patella Alta

Patellar position is best evaluated on a lateral radiograph with the knee flexed approximately 30°.

Insall–Salvati Ratio

The Insall–Salvati ratio compares:

Patellar tendon length with the greatest diagonal length of the patella.

A value near 1.0 is typical.

A deviation of more than approximately 20% may suggest:

Patella alta or patella baja.

Lyme Disease Imaging and Testing

Plain radiographs are generally nonspecific and mainly help exclude other causes of knee swelling.

Diagnosis of Lyme arthritis relies primarily on:

Clinical findings, appropriate exposure history, and positive serologic testing.

Important Clinical Principle

Pediatric knee symptoms should always be interpreted in relation to the child’s:

Age, skeletal maturity, alignment, activity level, gait, hip examination, pain location, swelling, and systemic symptoms.

Particularly important diagnoses not to miss include:

Septic arthritis, SCFE presenting as knee pain, malignancy, osteomyelitis, unstable osteochondral lesions, and major ligament or physeal injury.

Orthopaedic Surgery - Knee Dislocation

Basics

Knee dislocation is an orthopaedic emergency because of the substantial risk of associated vascular, neurologic, and multiligament injury.

Most cases result from high-energy trauma, although sports injuries and even low-energy falls can also cause dislocation.

A knee that has spontaneously reduced before evaluation may appear relatively normal despite having sustained a major injury. For this reason, the diagnosis should be considered whenever there is evidence of severe multiligament instability or a compatible mechanism.

Classification by Direction

Knee dislocations are classified according to the position of the tibia relative to the femur.

Anterior Dislocation

The tibia is displaced anteriorly relative to the femur.

Posterior Dislocation

The tibia is displaced posteriorly.

Posterior dislocations are particularly concerning for injury to the popliteal artery because of the close relationship between the vessel and the posterior knee.

Medial Dislocation

The tibia is displaced medially relative to the femur.

Lateral Dislocation

The tibia is displaced laterally.

Rotary Dislocation

Rotational injuries can be further described as:

Anteromedial, anterolateral, posteromedial, or posterolateral.

Classification by Injury Energy

The injury may also be classified according to the amount of energy involved.

High-Energy

High-energy dislocations typically result from:

Motor vehicle collisions, falls from height, or other major trauma.

These injuries have a greater risk of:

Vascular disruption, extensive soft-tissue damage, fractures, open wounds, and compartment syndrome.

Low-Energy

Low-energy knee dislocation may occur during sports, twisting injuries, or moderate trauma.

Ultralow-Energy

Some dislocations occur after seemingly minor trauma, particularly in patients with substantial obesity or ligamentous vulnerability.

Even these injuries can cause serious neurovascular damage.

Epidemiology

Knee dislocation is uncommon, historically reported in fewer than 0.02% of musculoskeletal injuries.

The true incidence is probably higher because many dislocations spontaneously reduce before the patient is examined and may therefore be missed.

Sex

Historical series report a male predominance of approximately 2.5:1.

Associated Injuries

Knee dislocation frequently damages multiple structures.

Important associated injuries include:

Popliteal artery injury, common peroneal nerve injury, tibial or femoral fractures, rupture of the cruciate ligaments, rupture of the collateral ligaments, posterolateral corner injury, and extensive capsular disruption.

Diagnosis

History

The mechanism and amount of energy involved should be determined whenever possible.

Important questions include:

Direction of force, presence of twisting, direct impact, speed of injury, open wounds, loss of sensation, weakness, and whether the knee appeared deformed before spontaneously reducing.

Signs and Symptoms

A classic unreduced knee dislocation presents with:

Gross deformity, severe pain, swelling, inability to move the knee, and inability to bear weight.

However, deformity may be absent if the joint has reduced spontaneously or was reduced before orthopaedic evaluation.

Neurovascular Injury

Careful assessment of vascular and neurologic function is essential in every suspected knee dislocation.

Popliteal Artery Injury

Historical series report popliteal artery injury in approximately 32–45% of knee dislocations.

Because the artery is tethered proximally and distally around the knee, major displacement can produce:

Intimal tearing, thrombosis, transection, or stretch injury.

Peroneal Nerve Injury

Nerve injury occurs in approximately 16–40% of cases in older series.

The common peroneal nerve is the nerve most frequently affected.

Vascular Red Flags

Urgent vascular evaluation is required when there is:

Absent or diminished pulse, asymmetric pulses, cool or cyanotic foot, delayed capillary refill, expanding hematoma, popliteal ecchymosis, active bleeding, or loss of motor or sensory function.

Physical Examination

Trauma Assessment

High-energy injuries should first undergo a complete trauma evaluation according to standard trauma priorities.

Inspection

Examine for:

Deformity, swelling, bruising, open wounds, skin tenting, and evidence of associated fracture.

Vascular Examination

Document:

Dorsalis pedis and posterior tibial pulses, capillary refill, foot temperature, skin color, and symmetry with the opposite limb.

A Doppler examination may be used when pulses are difficult to palpate.

Important Point

The presence of palpable distal pulses does not completely exclude vascular injury.

An intimal flap can preserve flow initially and subsequently thrombose.

Ankle-Brachial Index

An ankle-brachial index (ABI) should be obtained when appropriate.

An abnormal or asymmetric ABI increases concern for occult arterial injury and may prompt CT angiography or vascular consultation.

Neurologic Examination

Motor and sensory function should be documented before and after reduction.

Particular attention should be given to the:

Common peroneal and tibial nerves.

Peroneal Nerve

Assess:

Ankle dorsiflexion, great-toe extension, foot eversion, and sensation over the dorsum of the foot.

Tibial Nerve

Assess:

Plantarflexion, toe flexion, and plantar foot sensation.

Ligament Examination

The knee should be assessed systematically for injury to the:

ACL, PCL, MCL, LCL, and posterolateral corner.

Laxity involving two or more major ligaments strongly suggests that a knee dislocation has occurred, even if the joint is reduced at presentation.

Compartment Syndrome

Patients require repeated examination because compartment syndrome can develop after vascular injury, reperfusion, fracture, or severe soft-tissue trauma.

Warning Signs

Particularly concerning findings include:

Severe pain out of proportion to the injury and pain with passive stretch of the ankle or toes.

Other findings such as tense compartments, weakness, or sensory changes may occur later.

Imaging

Plain Radiographs

Obtain:

AP and lateral radiographs of the knee.

Radiography should not delay immediate reduction when an obvious dislocation is present.

Post-reduction radiographs are required to confirm alignment and identify associated fractures.

CT Angiography

CT angiography is useful when there is:

Abnormal perfusion, pulse asymmetry, abnormal ABI, suspicious examination findings, or uncertainty regarding vascular integrity.

MRI

MRI is useful for defining:

Cruciate ligament tears, collateral ligament injuries, posterolateral corner injuries, meniscal damage, cartilage injury, and other soft-tissue abnormalities.

It is usually obtained after the acute emergency has been stabilized rather than before reduction or vascular evaluation.

Schenck Classification of Multiligament Knee Injury

The Schenck system classifies knee dislocation according to the ligament structures disrupted.

KD I

One cruciate ligament plus a collateral ligament or posterolateral structure is injured.

KD II

Both the ACL and PCL are torn, with collateral structures relatively preserved.

KD III-M

The ACL, PCL, and MCL are injured.

Additional medial or posteromedial structures may also be involved.

KD III-L

The ACL, PCL, LCL, and posterolateral corner are injured.

KD IV

All four major ligament groups are disrupted:

ACL, PCL, MCL, and LCL/posterolateral corner.

KD V

A knee dislocation occurs in association with a periarticular fracture, producing a fracture-dislocation.

Moore Classification of Knee Fracture-Dislocations

The Moore classification describes associated tibial plateau fracture patterns.

Type I

Split fracture involving the medial or lateral plateau.

Type II

Complete fracture separating essentially an entire medial or lateral plateau.

Type III

Rim avulsion fracture.

Type IV

Rim compression fracture.

Type V

Four-part fracture pattern.

Differential Diagnosis

Conditions that may mimic or accompany knee dislocation include:

Patellar dislocation, isolated vascular injury, femoral fracture, tibial fracture, isolated ligament injury, and fracture-dislocation around the knee.

Treatment

Immediate Reduction

An unreduced knee dislocation should be reduced urgently.

The goal is to restore:

Alignment, vascular perfusion, nerve function, and soft-tissue tension.

Reduction Principles

Reduction should be performed using:

Gentle longitudinal traction and controlled correction of the deformity.

Forceful focal pressure should be avoided because it may worsen vascular, neurologic, or soft-tissue injury.

Anterior Dislocation

Reduction generally involves:

Longitudinal traction with controlled posterior translation of the tibia and manipulation of the femur as necessary.

Posterior Dislocation

Reduction typically uses:

Longitudinal traction with anterior elevation of the proximal tibia while the knee is carefully extended.

Medial and Lateral Dislocations

Traction is combined with controlled correction of the medial or lateral displacement.

Post-Reduction Care

After reduction:

Repeat and document the complete neurovascular examination.

Then obtain appropriate radiographs and vascular assessment.

Irreducible Knee Dislocation

Some knee dislocations cannot be reduced by closed manipulation.

Dimple Sign

A skin dimple over the medial joint line between the medial femoral condyle and medial tibial plateau suggests that the medial femoral condyle has buttonholed through the medial capsule, trapping soft tissue such as the MCL within the joint.

This finding strongly suggests an irreducible dislocation.

Management

Irreducible dislocations usually require open surgical reduction.

Repeated forceful attempts at closed reduction should be avoided.

Immobilization

After reduction, the knee is stabilized with either:

A well-padded splint or a spanning external fixator, depending on stability and associated injuries.

Indications for Spanning External Fixation

External fixation may be required when there is:

Persistent gross instability, vascular repair requiring protection, open injury, severe soft-tissue compromise, polytrauma, or inability to maintain reduction in a splint.

Vascular Injury

Any confirmed or strongly suspected arterial injury requires emergency vascular surgery evaluation.

Revascularization

Repair may require:

Primary repair, thrombectomy, patch angioplasty, bypass, or interposition grafting, often using autologous saphenous vein.

Timing

Limb viability is closely related to ischemia time.

Delays approaching or exceeding 8 hours have historically been associated with a dramatic increase in amputation risk.

For this reason, suspected vascular injury must be treated urgently.

Fasciotomy

Fasciotomy may be necessary when there is:

Compartment syndrome, prolonged ischemia, substantial reperfusion injury, or severe swelling after vascular reconstruction.

Open Dislocation

An open knee dislocation requires urgent operative management including:

Irrigation, debridement, reduction, stabilization, antibiotic therapy, and treatment of associated ligamentous or vascular injury.

Nonoperative Treatment

Nonoperative treatment may be considered when:

There is no vascular injury, the patient has low functional demands, advanced age, major medical comorbidities, or surgical reconstruction is contraindicated.

Immobilization

Protected immobilization may continue for approximately 6–8 weeks, although prolonged immobilization increases the risk of stiffness.

Surgical Treatment

Definitive ligament repair or reconstruction is commonly considered after initial stabilization.

Timing depends on:

Soft-tissue swelling, vascular repair, open wounds, associated fractures, overall patient condition, and surgeon strategy.

Historically, reconstruction has often been performed after approximately 10–14 days, once swelling has decreased, although staged and earlier approaches are also used.

Ligament Reconstruction

Surgical strategy depends on which structures are injured.

Accurate restoration of:

Joint alignment, cruciate stability, collateral stability, and posterolateral stability

is necessary to restore functional knee mechanics.

The sequence of reconstruction is important and should be individualized according to the pattern of injury.

Activity

Nonoperative Patients

Protected immobilization is generally maintained initially.

Quadriceps-setting exercises can often begin while the patient remains immobilized.

Operative Patients

Postoperative activity depends on:

Which ligaments were repaired or reconstructed, meniscal or cartilage injury, associated fractures, and vascular procedures.

Range of Motion

Progressive active or assisted range of motion commonly begins after the initial protective period.

Some protocols begin earlier when fixation and reconstruction are sufficiently stable.

Physical Therapy

Rehabilitation is essential.

Early goals include:

Edema control, quadriceps activation, protection of reconstructed structures, and prevention of excessive stiffness.

Later phases emphasize:

Progressive range of motion, strengthening, proprioception, gait training, and functional retraining.

Return to Activity

Recovery is prolonged.

Historical approximate timelines include:

Sedentary work: around 2 months

Heavy labor: approximately 6–9 months

Return to sport: approximately 9–12 months or longer

Actual timing depends on injury severity and reconstruction.

Follow-Up

Patients should be followed closely, often at approximately 4–6 week intervals during recovery, until stability, motion, strength, and function have plateaued.

Referral

An orthopaedic surgeon should be consulted emergently for any suspected knee dislocation.

A vascular surgeon should be involved immediately when arterial injury is suspected or confirmed.

Prognosis

Outcome depends heavily on:

Energy of injury, vascular damage, nerve injury, number of ligaments torn, cartilage injury, associated fracture, and success of reconstruction.

High-energy injuries generally have worse functional results.

Vascular Prognosis

When arterial injury is present, the likelihood of limb salvage declines as ischemia time increases.

Historical data reported an amputation rate as high as approximately 86% when ischemia persisted beyond 8 hours.

Arthrofibrosis

Loss of knee motion is one of the most common long-term problems.

Nonoperative Treatment

Residual stiffness may provide some stability in a chronically ligament-deficient knee but can substantially impair function.

Operative Treatment

Reconstruction may itself increase stiffness risk, particularly when prolonged immobilization is required.

Stable reconstruction that permits controlled early motion helps reduce this risk.

Motion Loss Patterns

Loss of extension may occur after ACL reconstruction, whereas loss of flexion can occur after PCL reconstruction.

Neurologic Deficit

Common peroneal nerve injury is a frequent sequela.

Recovery can take:

Months to years, and prognosis varies according to whether the injury represents neurapraxia, axonal disruption, or complete nerve injury.

Persistent foot drop may require bracing, tendon transfer, or other reconstructive procedures.

Chronic Instability

Residual instability may occur because of incomplete healing or reconstruction of the damaged ligaments.

True redislocation after definitive treatment is uncommon.

Post-Traumatic Arthritis

Articular cartilage injury at the time of dislocation can lead to progressive degenerative disease.

Historical studies have reported post-traumatic arthritis in a large proportion of patients, in some series approaching 87%.

Patient Monitoring

Patients require careful monitoring during both the acute and recovery phases.

Important parameters include:

Distal perfusion, pulses, ABI when indicated, motor and sensory function, compartment status, skin condition, wound healing, ligament stability, range of motion, and radiographic alignment.

Particular attention should be paid to detecting:

Delayed vascular thrombosis, compartment syndrome, arthrofibrosis, persistent instability, nerve dysfunction, and post-traumatic arthritis.

Orthopaedic Surgery - Knee Anatomy and Examination

Basics

The knee is a complex synovial joint composed of bone, articular cartilage, menisci, ligaments, tendons, muscles, nerves, and vascular structures.

A systematic understanding of this anatomy is essential for interpreting pain, instability, swelling, mechanical symptoms, and loss of motion.

Bony Anatomy

The principal bones forming the knee are the:

Femur, tibia, and patella.

Femur

The medial and lateral femoral condyles articulate with the tibial plateau to form the tibiofemoral joint.

Anteriorly, the femoral trochlea articulates with the patella.

Tibia

The medial and lateral tibial plateaus articulate with the corresponding femoral condyles.

The tibia transmits the majority of axial load through the knee.

Patella

The patella articulates with the femoral trochlea and is embedded within the extensor mechanism.

It acts as a fulcrum that increases the mechanical advantage of the quadriceps, thereby improving knee-extension strength.

Articular Cartilage

Hyaline cartilage covers the articulating surfaces of the:

Femoral condyles, tibial plateaus, trochlea, and posterior patellar surface.

Loss or injury of this cartilage may produce pain, crepitus, swelling, and degenerative arthritis.

Menisci

The medial and lateral menisci are fibrocartilaginous structures located between the femoral condyles and tibial plateaus.

They contribute to:

Load distribution, shock absorption, joint congruity, stability, lubrication, and protection of the articular cartilage.

Medial Meniscus

The medial meniscus is relatively firmly attached to the joint capsule and deep medial collateral ligament, making it less mobile than the lateral meniscus.

Lateral Meniscus

The lateral meniscus is more mobile and covers a larger proportion of the lateral tibial plateau.

Extensor Mechanism

The extensor mechanism consists primarily of:

Quadriceps muscle and tendon, patella, patellar tendon, and tibial tuberosity.

Quadriceps Tendon

The quadriceps tendon inserts on the superior pole of the patella.

Patellar Tendon

The patellar tendon extends from the inferior pole of the patella to the tibial tuberosity.

Together with the quadriceps tendon and patella, it transmits quadriceps force to extend the knee.

Anterior Cruciate Ligament

The ACL originates from the posteromedial surface of the lateral femoral condyle and inserts on the anterior intercondylar region of the tibia.

Its major function is to resist:

Anterior translation of the tibia relative to the femur.

It also contributes to rotational stability.

Posterior Cruciate Ligament

The PCL originates from the anterolateral surface of the medial femoral condyle and inserts on the posterior intercondylar region of the tibia.

Its primary role is to resist:

Posterior translation of the tibia relative to the femur, particularly during knee flexion.

Medial Collateral Ligament

The MCL originates near the medial femoral epicondyle and inserts along the medial proximal tibia.

Its deep fibers have connections with the medial capsule and medial meniscus.

The MCL is the principal restraint to valgus stress.

Lateral Collateral Ligament and Posterolateral Corner

The LCL originates from the lateral femoral epicondyle and inserts on the fibular head.

Together with the posterolateral corner structures, it helps resist:

Varus stress, external rotation of the tibia, and posterolateral instability.

The posterolateral corner is a complex of several stabilizing structures rather than the LCL alone.

Muscles

Knee Extensors

The quadriceps muscle group consists of:

Rectus femoris, vastus lateralis, vastus intermedius, and vastus medialis.

These muscles extend the knee.

Knee Flexors

Major flexors include the:

Biceps femoris, semimembranosus, semitendinosus, and gracilis.

Other muscles also contribute to knee flexion and rotation.

Nerves

Femoral Nerve

The femoral nerve supplies the quadriceps and is therefore critical to active knee extension.

Sciatic Nerve

The sciatic nerve travels posteriorly in the thigh and divides into the tibial and common peroneal nerves near the knee.

Common Peroneal Nerve

The common peroneal nerve passes laterally around the fibular neck, where it is relatively superficial and vulnerable to injury.

Diagnosis and Examination

A complete knee examination should follow a consistent sequence and should generally include:

Inspection, gait assessment, range of motion, palpation, evaluation for effusion, ligament testing, meniscal testing, patellofemoral assessment, and a complete neurovascular examination.

Initial Assessment

The unaffected knee should be examined for comparison.

The clinician should also consider referred pain from the:

Hip, lumbar spine, or surrounding soft tissues.

Neurovascular Examination

Motor function, sensation, peripheral pulses, and capillary refill should be assessed when appropriate.

Range of Motion

Normal knee motion is approximately:

0–140°, although values vary with age and body habitus.

Many individuals have a small degree of physiologic hyperextension.

Flexion Contracture

A flexion contracture is present when the knee cannot reach full extension either actively or passively.

Extension Lag

An extension lag exists when:

Full passive extension is possible, but the patient cannot actively achieve it.

This may indicate weakness or disruption of the extensor mechanism.

Symmetry

Knee motion should be compared with the contralateral side.

Inspection

Observe for:

Erythema, swelling, effusion, abrasions, scars, deformity, muscle wasting, and abnormal patellar position.

Muscle Atrophy

Quadriceps wasting may accompany chronic knee pain, instability, arthritis, or prolonged immobilization.

Alignment

Standing alignment should be assessed in the coronal and rotational planes.

Varus and Valgus

Physiologic lower-extremity alignment usually includes several degrees of valgus.

Historical averages are approximately:

5° of valgus in males and 7° in females, although individual variation is substantial.

Rotational Alignment

The direction of the patellae and feet during standing and walking can provide clues about rotational alignment of the lower extremities.

Gait Examination

The patient should be observed walking whenever possible.

Antalgic Gait

An antalgic gait is characterized by:

Reduced stance time on the painful side and shortened stride length.

Palpation

With the knee flexed to approximately 90°, systematically palpate:

Quadriceps tendon, patella, patellar tendon, medial and lateral joint lines, MCL, LCL, tibial tuberosity, iliotibial band, femoral epicondyles, and other areas of reported tenderness.

The location of tenderness should be correlated with underlying anatomy.

Knee Effusion

An intra-articular effusion may result from:

Hemarthrosis, inflammation, infection, arthritis, meniscal injury, ligament injury, or intra-articular fracture.

Hemarthrosis

Acute hemarthrosis may occur with:

ACL rupture, patellar dislocation, intra-articular fracture, or major meniscal or ligament injury.

Warmth

Increased warmth may indicate active inflammation or infection.

Patellar Ballottement / Blot Test

The patella is gently compressed toward the femoral trochlea.

With a substantial effusion, the patella may feel as though it floats or rebounds as fluid redistributes within the joint.

Prepatellar Bursitis

Prepatellar bursitis presents as:

Localized swelling directly anterior to the patella, often accompanied by anterior knee pain and tenderness.

The swelling is extra-articular.

Popliteal or Baker Cyst

A Baker cyst appears as swelling or fullness in the popliteal fossa.

It often reflects underlying intra-articular pathology such as:

Arthritis, meniscal disease, or chronic synovitis.

Iliotibial Band Syndrome

Iliotibial band syndrome commonly produces:

Lateral knee pain over the lateral femoral epicondyle, particularly in runners and cyclists.

It is usually an overuse condition.

Ober Test

The Ober test assesses iliotibial band tightness.

Technique

The patient lies on the unaffected side.

The pelvis is stabilized while the affected hip is abducted and extended.

The examiner then allows the leg to move toward adduction.

Positive Test

If the leg remains abducted rather than dropping toward the table, iliotibial band tightness is suggested.

Lateral knee pain may also be reproduced.

Extensor Mechanism Injury

Patellar fracture, quadriceps tendon rupture, and patellar tendon rupture may disrupt active knee extension.

Findings

Potential findings include:

Palpable tendon defect, extension lag, abnormal patellar position, and inability to perform an active straight-leg raise or actively extend the knee.

Patellofemoral Pain

Patellofemoral disorders commonly produce anterior knee pain.

Symptoms are often aggravated by:

Running, stair climbing, squatting, prolonged sitting, or rising from a seated position.

Q Angle

The Q angle is formed by the intersection of:

A line from the anterior superior iliac spine to the center of the patella, and a line from the patella to the tibial tuberosity.

Historically, an angle greater than approximately 15° has been associated with patellofemoral symptoms, although Q angle alone is a limited predictor of pathology.

Patellar Glide Test

With the knee extended or slightly flexed, the patella is translated medially and laterally.

Patellar mobility may be described in quadrants.

Excessive Translation

Translation greater than approximately two quadrants may suggest patellar hypermobility or instability, especially when asymmetric.

Patellar Apprehension Test

With the knee relaxed, the patella is translated laterally.

A positive test occurs when the patient develops marked apprehension or attempts to stop the maneuver.

This suggests lateral patellar instability.

Patellar Grind Test

The patella is compressed against the trochlea while the patient contracts the quadriceps.

Pain or crepitus may be produced in patients with patellofemoral pathology.

Because this maneuver can be uncomfortable even in normal knees, it should be interpreted cautiously.

Ligamentous Instability

The mechanism of injury often suggests which ligament is injured.

ACL Mechanism

ACL rupture commonly follows a:

Noncontact pivoting, cutting, or twisting injury with the foot planted, sometimes accompanied by an audible or palpable “pop.”

An acute hemarthrosis frequently develops.

PCL Mechanism

PCL injury classically follows a posteriorly directed force on the proximal tibia with the knee flexed, as in a dashboard injury.

MCL Mechanism

MCL injury typically results from a valgus force applied to the lateral side of the knee.

Symptoms of Instability

Patients may describe the knee as:

Giving way, buckling, or shifting, particularly during cutting or pivoting activities.

Varus and Valgus Stress Tests

These tests evaluate the collateral ligaments.

Technique

Apply valgus or varus stress with the knee:

In full extension and at approximately 30° of flexion.

Testing at 30° better isolates the collateral ligaments, whereas instability in full extension suggests injury to additional capsular or cruciate structures.

Grading

Traditional grading based on joint opening is:

Grade 1: less than 5 mm.

Grade 2: approximately 5–10 mm.

Grade 3: greater than 10 mm.

Comparison with the opposite knee is important.

Lachman Test

The Lachman test is one of the most sensitive clinical tests for ACL insufficiency.

Technique

With the knee relaxed at approximately 20–30° of flexion, stabilize the distal femur with one hand and translate the proximal tibia anteriorly with the other.

Positive Test

A positive test demonstrates:

Increased anterior translation and/or a soft or absent endpoint compared with the opposite knee.

Historically, more than approximately 5 mm of translation or more than 3 mm of side-to-side difference has been considered abnormal.

Grading

Grade 1: less than 5 mm.

Grade 2: 5–10 mm.

Grade 3: greater than 10 mm.

The endpoint may be described as:

A = firm endpoint

B = soft endpoint

Anterior Drawer Test

The anterior drawer test assesses ACL integrity.

Technique

With the knee flexed to 90° and the foot stabilized, grasp the proximal tibia and pull it anteriorly.

Excessive anterior translation suggests ACL insufficiency.

Posterior Drawer Test

With the same position, the tibia is pushed posteriorly.

Excessive posterior translation indicates PCL insufficiency.

Drawer Grading

Traditional grading is:

Grade 1: less than 5 mm.

Grade 2: 5–10 mm.

Grade 3: greater than 10 mm.

Dial Test

The dial test assesses posterolateral rotational instability.

Technique

The patient is often positioned prone.

Externally rotate both feet and compare the thigh-foot angles at approximately:

30° and 90° of knee flexion.

Positive Test

An increase in external rotation greater than approximately 10° compared with the opposite side is considered abnormal.

Interpretation

Increased external rotation primarily at 30° suggests an isolated posterolateral corner injury.

Increased rotation at both 30° and 90° suggests combined posterolateral corner and PCL injury.

Meniscal Pathology

Meniscal tears commonly cause:

Joint-line pain, swelling, catching, clicking, locking, or episodic mechanical symptoms.

A displaced tear such as a bucket-handle tear may produce a knee locked in flexion.

Joint-Line Tenderness

Tenderness is best assessed with the knee flexed to approximately 90°.

Focal tenderness along the affected joint line supports a meniscal lesion.

McMurray Test

The McMurray test attempts to reproduce symptoms from a meniscal tear during knee rotation and extension.

Medial Meniscus

To test the medial meniscus:

Flex the knee fully, externally rotate the tibia, and apply a valgus stress while gradually extending the knee.

Palpate the medial joint line.

Lateral Meniscus

To test the lateral meniscus:

Flex the knee, internally rotate the tibia, and apply a varus stress while extending the knee.

Palpate the lateral joint line.

Positive Test

A reproducible:

Painful click, clunk, or mechanical sensation at the joint line

suggests meniscal pathology.

Apley Compression Test

The patient lies prone with the knee flexed to approximately 90°.

Axial compression is applied through the heel while the tibia is internally and externally rotated.

Interpretation

Pain at the:

Medial joint line suggests possible medial meniscal injury.

Pain at the:

Lateral joint line suggests possible lateral meniscal injury.

The test should be interpreted together with the history and other examination findings.

Knee Arthritis

Patients with knee arthritis commonly report:

Activity-related pain, stiffness, swelling, loss of motion, and reduced walking tolerance.

Physical Findings

Examination may demonstrate:

Crepitus, palpable osteophytes, effusion, flexion contracture, reduced range of motion, deformity, and functional limitation.

Pseudolaxity

Advanced compartmental cartilage loss may create apparent varus or valgus laxity.

This is called pseudolaxity because the apparent opening results from joint-space loss and deformity rather than true ligament rupture.

Imaging in Arthritis

Radiographs may demonstrate:

Joint-space narrowing, osteophytes, subchondral sclerosis, cystic change, and deformity.

Weight-bearing radiographs are especially useful for evaluating compartmental joint-space loss.

General Examination Strategy

A complete knee assessment should integrate:

History, mechanism of injury, gait, alignment, range of motion, effusion, tenderness, patellofemoral examination, ligament testing, meniscal testing, and neurovascular status.

No single special test should be interpreted in isolation.

The most reliable diagnosis comes from correlating the history, examination findings, and appropriate imaging.

Orthopaedic Surgery - Klippel–Feil Syndrome

Basics

Klippel–Feil syndrome is a congenital disorder characterized by failure of normal segmentation of the cervical vertebrae during embryonic development, resulting in congenital fusion of two or more cervical vertebrae.

The classic clinical triad is:

A short neck, low posterior hairline, and restricted cervical range of motion.

However, the complete triad is present in only a minority of patients.

Associated Abnormalities

Klippel–Feil syndrome frequently occurs with abnormalities in other organ systems.

Common associations include:

Congenital scoliosis, Sprengel deformity, hearing impairment, synkinesis, congenital heart disease, renal abnormalities, and spinal dysraphism.

Classification

A traditional classification divides the disorder according to the distribution of vertebral fusion.

Type I

Type I consists of extensive fusion involving the:

Cervical and upper thoracic vertebrae.

Type II

Type II involves fusion confined predominantly to the cervical spine.

One or several cervical motion segments may be fused.

Type III

Type III describes cervical fusion associated with additional congenital fusion involving the:

Lower thoracic or lumbar spine.

Prevention

There are no established preventive measures because the condition develops during embryogenesis.

Epidemiology

The congenital segmentation abnormality develops early in fetal life.

The age at diagnosis varies considerably according to the severity of the fusion and associated abnormalities.

Early Presentation

Extensive cervical fusion is more likely to be recognized during early childhood, sometimes around 2–4 years of age, because of visible neck shortening, limited motion, or associated deformity.

Later Presentation

Less extensive disease may remain asymptomatic for many years.

Some patients are diagnosed incidentally during imaging, while others first become symptomatic when adjacent-segment degeneration, stenosis, or instability develops later in life.

Sex

A slight female predominance has been described, with historical female-to-male ratios around 1.5:1.

Neurologic Symptoms

Most children are neurologically normal.

Symptomatic cervical stenosis or adjacent-segment degeneration may become more apparent in adulthood, particularly during the fourth decade and beyond.

Symptoms may include sensory disturbance, weakness, gait abnormality, or myelopathic findings.

Incidence

Congenital cervical fusion has historically been reported in approximately 0.7% of the population, although prevalence varies according to imaging technique and diagnostic criteria.

Risk Factors and Associated Developmental Abnormalities

Associated abnormalities include:

Spina bifida and congenital renal malformations.

The presence of one congenital anomaly should prompt consideration of others.

Genetics

Klippel–Feil syndrome is genetically heterogeneous.

Many cases are sporadic, while familial cases may follow different inheritance patterns.

Inheritance

Autosomal dominant forms have been documented, and autosomal recessive forms are also recognized in some genetic subtypes.

Molecular Associations

Abnormalities involving genes that regulate vertebral segmentation and embryonic development have been implicated.

Research has identified associations with pathways involving somitogenesis and Notch signaling, while specific families have demonstrated chromosomal abnormalities such as an inversion involving 8q22.2–q23.3.

The genetic basis is therefore variable rather than attributable to one universal mutation.

Etiology

The fundamental developmental abnormality is incomplete segmentation of the cervical sclerotomes during embryogenesis.

Normally, adjacent portions of developing vertebral segments separate and reorganize into individual vertebrae.

Failure of this process produces congenital block vertebrae.

Proposed Mechanisms

Additional proposed mechanisms include:

Abnormal facet-joint segmentation, vascular disruption, fetal hypoxia, or other developmental insults affecting vertebral formation.

These mechanisms remain incompletely defined.

Associated Conditions

Musculoskeletal Abnormalities

Common musculoskeletal associations include:

Sprengel deformity, congenital or idiopathic scoliosis, spinal stenosis, cervical instability, and spina bifida occulta.

Sprengel Deformity

Sprengel deformity results from failure of normal descent of the scapula during development.

The affected scapula remains elevated and may contribute to:

Restricted shoulder motion, cosmetic asymmetry, and cervical or upper thoracic deformity.

Scoliosis

Scoliosis has been reported in up to approximately 60% of patients in some series.

Curves may be congenital, compensatory, or idiopathic.

Spinal Stenosis

The cervical spinal canal may be congenitally narrow or may become stenotic later because of:

Adjacent-segment degeneration, osteophyte formation, disc degeneration, or instability.

Craniofacial and Neurologic Associations

Possible abnormalities include:

Hearing loss, extraocular muscle palsy, synkinesis, and other cranial nerve abnormalities.

Genitourinary Abnormalities

Renal anomalies occur in a substantial minority of patients, historically reported in up to approximately 30%.

These may include:

Unilateral renal agenesis, ectopic kidney, collecting-system abnormalities, or other congenital renal malformations.

Cardiovascular Abnormalities

Congenital heart defects may occur and should be investigated when clinically suspected.

Diagnosis

Signs and Symptoms

The classic triad consists of:

Short neck, low posterior hairline, and restricted cervical motion.

The full triad is found in only approximately 40–50% of patients.

Limited Motion

Restricted cervical motion is one of the most common findings and has been reported in up to approximately 75% of affected patients.

Short Neck

Visible neck shortening and a correspondingly low posterior hairline are present in fewer than half of patients.

Incidental Diagnosis

Some patients have no obvious clinical abnormalities and are diagnosed after cervical fusion is discovered incidentally on radiographs or other imaging.

Other Presentations

Additional findings may include:

Scoliosis, shoulder asymmetry, hearing impairment, neurologic symptoms, renal anomalies, or congenital heart disease.

Physical Examination

A systematic examination should include both the cervical spine and screening for associated abnormalities.

Inspection

Assess:

Neck length, posterior hairline, head posture, cervical alignment, shoulder height, scapular position, and scoliosis.

Cervical Range of Motion

Document:

Flexion, extension, lateral bending, and rotation.

The degree of limitation depends on the number and location of fused segments.

Neurologic Examination

A complete neurologic examination is essential.

Assess:

Upper- and lower-extremity strength, sensation, reflexes, gait, coordination, pathologic reflexes, and signs of myelopathy.

Myelopathic Findings

Findings such as:

Hyperreflexia, clonus, pathologic reflexes, gait imbalance, hand clumsiness, or weakness

may indicate cervical spinal cord compression.

Examination for Associated Anomalies

The physical examination should also assess for:

Sprengel deformity, scoliosis, limb abnormalities, renal or genitourinary anomalies, hearing impairment, and cardiovascular findings.

Imaging

Plain Radiographs

Conventional cervical radiographs demonstrate varying patterns of congenital vertebral fusion.

Findings range from:

A single block vertebra to multiple contiguous fused segments.

Fusion Patterns

Different portions of the vertebra may be fused.

Historical series have reported combinations involving the:

Vertebral bodies, posterior elements, or lateral components.

Some patients demonstrate fusion of both anterior and posterior elements.

Spina Bifida Occulta

Associated posterior-element abnormalities, including spina bifida occulta, may be visible.

Adjacent-Segment Degeneration

Mobile segments immediately above or below a congenital fusion are exposed to greater mechanical stress.

Over time, they may develop:

Disc degeneration, facet arthrosis, instability, subluxation, or stenosis.

Flexion-Extension Radiographs

Dynamic lateral flexion and extension radiographs are useful for assessing:

Occult instability and excessive motion at adjacent segments.

These studies are particularly important before procedures requiring manipulation of the cervical spine, including anesthesia and intubation when instability is suspected.

MRI

MRI is indicated when there is concern for:

Spinal cord compression, nerve-root compression, stenosis, disc disease, congenital spinal cord abnormalities, or neurologic symptoms.

It is also useful before cervical spine surgery.

CT

CT may be useful for defining:

Complex bony anatomy, fused posterior elements, congenital anomalies, and preoperative surgical anatomy.

Pathological Findings

The primary abnormality is congenital fusion of cervical vertebrae.

Intervertebral Discs

Discs at the fused levels may be:

Narrow, rudimentary, or absent.

Adjacent Discs

Remaining mobile discs may undergo accelerated degeneration because they compensate for the lost movement at fused levels.

Degenerative Changes

Progressive abnormalities can include:

Degenerative disc disease, facet arthrosis, spinal stenosis, and subluxation.

Differential Diagnosis

Important alternative causes of a short or stiff neck include:

Postsurgical cervical fusion, muscular torticollis, cervical spinal stenosis, and other congenital vertebral segmentation disorders.

Treatment

General Principles

Management depends on:

Neurologic status, cervical stability, severity of stenosis, pain, associated deformity, and involvement of other organ systems.

Most asymptomatic patients do not require cervical surgery.

Evaluation of Associated Organ Systems

All patients should be assessed for associated congenital abnormalities.

Renal Evaluation

A renal ultrasound is commonly used to screen for congenital renal anomalies.

Cardiac Assessment

Cardiac evaluation is indicated when examination, history, or associated congenital findings raise concern for structural heart disease.

Hearing Assessment

Because hearing loss is a recognized association, formal audiologic assessment should be considered, especially in children.

Pre-Anesthetic Assessment

Because some patients have occult cervical instability, careful cervical evaluation is important before general anesthesia.

When clinically indicated, flexion-extension radiographs or advanced imaging should be reviewed before airway manipulation.

Anesthesia personnel should be informed of the cervical fusion and any instability.

MRI Before Spine Surgery

MRI should be obtained when neurologic compromise is suspected and before operative treatment of cervical stenosis or instability.

Activity Modification

Patients with significant cervical fusion, instability, or stenosis should avoid activities that create excessive risk of neck trauma.

This may include:

Collision sports, high-impact activities, and occupations or recreational activities with substantial risk of head or cervical injury.

Restrictions should be individualized according to anatomy and stability.

Nonoperative Treatment

For symptomatic but neurologically stable patients, treatment may include:

Activity modification, analgesics, short-term cervical support, and physical therapy.

Cervical Collar

A cervical collar may provide temporary symptomatic relief but should not routinely be used indefinitely because prolonged immobilization can weaken cervical musculature.

Physical Therapy

Physical therapy may be useful for:

Posture, general conditioning, shoulder-girdle strength, balance, and maintenance of available cervical and thoracic mobility.

Forceful manipulation of the cervical spine should be avoided in patients with congenital instability or stenosis.

Medication

Medication is directed at symptom control.

First-Line Analgesia

NSAIDs may be used for pain when there are no contraindications.

Acetaminophen is another option.

Long-Term Opioids

Chronic maintenance opioid therapy generally has no routine role.

Other Treatments

Selected patients with radicular symptoms may undergo specialist-directed interventions such as epidural steroid injection, although treatment should be tailored to the specific neurologic pathology.

Surgery

Surgery is generally reserved for patients with:

Neurologic deficits, progressive myelopathy, documented instability, significant spinal stenosis, or disabling pain that has failed appropriate nonoperative treatment.

Cervical Fusion or Decompression

Operative treatment may involve:

Decompression, stabilization, fusion, or a combination of procedures, depending on the site of stenosis and instability.

Preoperative Evaluation

Because associated renal and cardiac abnormalities are common, patients undergoing major surgery may require assessment by:

Anesthesiology, internal medicine, cardiology, or other appropriate specialists.

Compensatory Spinal Curves

Scoliosis or compensatory curves below the congenital cervical fusion should be monitored carefully.

Some curves can progress substantially during growth.

Bracing

Bracing may be appropriate for selected flexible progressive curves.

Fusion

Progressive structural deformity that cannot be controlled nonoperatively may require spinal fusion.

Surgery for Associated Anomalies

Surgical treatment may also be required for associated disorders such as:

Sprengel deformity, severe scoliosis, cervical rib-related symptoms, or other congenital musculoskeletal abnormalities.

Follow-Up

Prognosis

Many patients remain asymptomatic or minimally symptomatic for years.

Others develop:

Neck pain, radiculopathy, weakness, myelopathy, or adjacent-segment degeneration later in life.

Outcome depends largely on the number and location of fused vertebrae and the presence of associated neurologic, renal, cardiac, or musculoskeletal abnormalities.

Complications

Spinal Stenosis

Cervical spinal stenosis may become progressively symptomatic with age.

Adjacent-Segment Degeneration

Hypermobile segments adjacent to congenital fusion are subjected to increased stress and may develop premature degenerative disease.

Instability

Excessive motion at unfused segments can lead to:

Subluxation, nerve-root compression, or spinal cord compromise.

Neurologic Injury

Patients with extensive cervical fusion or stenosis may be more vulnerable to neurologic injury after trauma.

Severe injury can result in:

Weakness, paraparesis, quadriparesis, or paralysis.

Patient Monitoring

Patients should be followed periodically by an orthopaedic or spine specialist, particularly during growth or when symptoms change.

Follow-up should assess:

Cervical range of motion, pain, neurologic status, spinal alignment, adjacent-segment degeneration, and development of instability or stenosis.

Patients with associated renal, cardiac, hearing, or other systemic abnormalities should also receive appropriate long-term follow-up with the relevant specialists.

Orthopaedic Surgery - Kienböck Disease

Basics

Kienböck disease is osteonecrosis, or avascular necrosis, of the lunate.

Progressive loss of lunate vascularity can lead to sclerosis, fragmentation, collapse of the lunate, altered carpal mechanics, loss of carpal height, and eventually secondary degenerative arthritis of the wrist.

The condition is also known as lunatomalacia.

Classification

The traditional staging system was described by Stahl and later modified by Lichtman.

Classification is based primarily on the radiographic appearance of the lunate and the degree of associated carpal collapse.

Stage 0

MRI demonstrates evidence of lunate osteonecrosis despite normal plain radiographs.

This represents very early disease.

Stage I

Plain radiographs are normal or may demonstrate subtle fracture lines within the lunate.

MRI may show abnormal signal consistent with osteonecrosis.

There is no lunate collapse.

Stage II

The lunate becomes sclerotic on radiographs, reflecting increased bone density associated with osteonecrosis.

Carpal alignment and lunate height remain relatively preserved.

Stage IIIA

There is collapse of the lunate, but major fixed carpal malalignment has not yet developed.

In the modified Lichtman classification, the radioscaphoid angle remains less than approximately 60°.

Stage IIIB

Lunate collapse is accompanied by:

Proximal migration of the capitate, fixed flexion or rotation of the scaphoid, and loss of carpal height.

A radioscaphoid angle greater than approximately 60° is characteristic.

Stage IV

Advanced disease is characterized by generalized degenerative arthrosis of the wrist in addition to lunate collapse and carpal malalignment.

Additional Classification Systems

More recent systems incorporate findings from:

MRI, arthroscopy, cartilage assessment, and lunate vascularity.

These may help guide treatment more precisely than plain radiographs alone.

Epidemiology

Kienböck disease most commonly affects young adults between approximately 20 and 40 years of age.

Sex

A consistent overall sex predominance has not been established, although the disorder has historically been reported more frequently in young, physically active male manual workers.

Pediatric Disease

Kienböck disease can occur in children and adolescents.

The prognosis may be more favorable in younger patients because of greater healing and remodeling potential.

Risk Factors

Several anatomic and vascular factors may increase susceptibility.

Negative Ulnar Variance

An ulnar-negative wrist refers to a distal ulna that is relatively shorter than the radius.

This configuration can increase the proportion of load transmitted through the radial side of the wrist and potentially increase stress across the lunate.

Negative ulnar variance has therefore historically been associated with Kienböck disease.

Lunate Vascularity

Some lunates receive blood from a relatively limited vascular pattern, occasionally through a single dominant nutrient vessel.

Reduced vascular redundancy may increase susceptibility to ischemic injury.

Hematologic Disease

Conditions that impair bone perfusion, such as sickle cell disease, may predispose to lunate osteonecrosis.

Trauma and Ligament Injury

Traumatic disruption of carpal ligaments or repeated wrist loading may alter forces across the lunate and contribute to disease development.

Genetics

No consistent hereditary or genetic pattern has been identified.

Etiology

The exact cause remains uncertain.

When Kienböck originally described the disorder in 1910, it was considered a form of lunate softening or osteomalacia.

Current understanding favors a multifactorial process involving impaired blood supply combined with repetitive mechanical stress.

Ischemic Theory

Loss or compromise of the lunate blood supply may cause bone death and structural weakening.

Mechanical Theory

Repetitive microtrauma or abnormal load transmission may produce repeated injury to a vulnerable lunate.

Combined Mechanism

The prevailing concept is that repetitive stress acts on a lunate already predisposed by vascular or anatomic factors.

Diagnosis

History

Most patients present with a gradually developing combination of:

Dorsal wrist pain, stiffness, reduced grip strength, and difficulty with loading activities.

Symptoms may initially be mild or intermittent.

Pain Location

Pain is usually centered over the dorsal central wrist in the region of the lunate.

Grip Weakness

Some patients complain more prominently of decreased grip strength than pain.

Progression

If disease advances, symptoms may become progressively worse and eventually reflect secondary wrist arthritis.

Trauma History

A number of patients report a recent wrist hyperextension injury, although it is not always clear whether the injury caused the disease or simply made an existing process symptomatic.

Physical Examination

Tenderness

Tenderness may be present over the:

Dorsal lunate and central wrist.

Some patients may also report discomfort near the anatomic snuffbox.

Range of Motion

Wrist flexion and extension may become restricted as disease progresses.

Grip Strength

Grip strength is frequently reduced compared with the opposite hand.

Swelling

Mild dorsal wrist swelling may occasionally be present.

Imaging

Plain Radiographs

Standard wrist radiographs usually include:

PA, lateral, and oblique views.

Radiographs may establish the diagnosis once structural changes develop.

Early Disease

Stage I disease may have normal radiographs or show only a subtle lucent or fracture-like line within the lunate.

Sclerosis

Stage II disease demonstrates increased density or sclerosis of the lunate.

Collapse

More advanced stages demonstrate:

Lunate flattening, fragmentation, loss of height, carpal collapse, and proximal capitate migration.

Ulnar Variance View

A standardized PA radiograph can be used to assess ulnar variance.

Historically, this has been obtained with the:

Shoulder abducted to approximately 90°, elbow flexed to 90°, and forearm in neutral rotation.

Correct positioning is important because forearm rotation can alter the apparent ulnar variance.

MRI

MRI is particularly useful in early disease when plain radiographs remain normal.

It can demonstrate:

Abnormal lunate marrow signal, areas of necrosis, residual vascularity, fracture lines, and surrounding marrow changes.

MRI also contributes to assessment of disease extent and potential treatment planning.

CT

CT can provide detailed assessment of:

Lunate fracture, fragmentation, collapse, sclerosis, and carpal architecture.

It may be especially useful for operative planning.

Arthroscopy

Wrist arthroscopy may allow direct evaluation of the articular cartilage of the lunate, radius, and adjacent carpal bones.

Cartilage status can influence whether a reconstructive or salvage procedure is appropriate.

Pathological Findings

Biopsy specimens demonstrate features typical of osteonecrosis, including dead bone and altered marrow architecture.

Lunate Fracture

A transverse fracture through the lunate is a commonly described structural failure pattern.

Repeated loading across necrotic bone may contribute to collapse.

Differential Diagnosis

Important alternative diagnoses include:

Scapholunate ligament injury, scaphoid fracture, perilunate injury, degenerative wrist arthritis, and ulnar impaction syndrome.

Scapholunate Ligament Injury

Scapholunate instability can cause dorsal central wrist pain and altered carpal alignment that may mimic later-stage Kienböck disease.

Scaphoid Fracture

A scaphoid fracture should be considered when there is radial-sided wrist pain, particularly after trauma.

Perilunate Injury

Perilunate dislocation or ligament injury may produce significant wrist pain and carpal malalignment.

Ulnar Impaction Syndrome

Ulnar-sided wrist pain related to positive ulnar variance differs mechanically from the negative ulnar variance classically associated with Kienböck disease.

Treatment

General Principles

Optimal treatment remains debated.

Management depends on:

Patient age, symptoms, disease stage, ulnar variance, degree of lunate collapse, carpal alignment, cartilage condition, and functional demands.

Initial Management

The wrist may initially be:

Splinted or immobilized, with referral to a hand or wrist specialist.

Activity modification and analgesia may also be used during the early symptomatic phase.

Natural History

Radiographic disease can progress even when symptoms are modest.

However, the relationship between radiographic progression and clinical disability is variable.

Some patients remain functional despite substantial imaging abnormalities.

Young and Elderly Patients

Children younger than approximately 15 years and elderly patients older than approximately 70 years may have a more favorable clinical course with nonoperative management.

Observation is therefore often reasonable initially in these groups.

Persistent symptoms beyond several months may prompt reconsideration of surgery.

Treatment According to Stage

Stage I and Stage II

Treatment aims to:

Reduce mechanical loading across the lunate and improve or preserve its blood supply.

Joint-Leveling Procedures

When negative ulnar variance is present, a radial shortening osteotomy may reduce load across the lunate.

Historically, ulnar lengthening has also been used, although radial shortening is more commonly performed.

Capitate Shortening

A capitate shortening osteotomy is another load-reducing option in selected patients.

Limited Intercarpal Fusion

Selective fusion procedures can redistribute forces away from the diseased lunate while preserving some wrist motion.

Revascularization

Vascularized bone grafting may be used in selected early-stage disease to improve lunate perfusion.

The graft may provide both:

Biologic revascularization and structural support.

Stage III Disease

When lunate collapse has occurred, treatment becomes more dependent on:

Carpal alignment, cartilage condition, age, and degree of collapse.

Proximal Row Carpectomy

A proximal row carpectomy removes the:

Scaphoid, lunate, and triquetrum.

This can provide pain relief while preserving a functional range of wrist motion in appropriately selected patients.

It requires relatively preserved cartilage at the capitate head and lunate fossa of the radius.

Limited Fusion

Partial wrist fusion may be used to stabilize the carpus and reduce pain while maintaining some movement.

Stage IV Disease

Stage IV disease involves established degenerative arthritis.

At this stage, reconstructive procedures aimed solely at preserving the lunate are generally no longer sufficient.

Total Wrist Arthrodesis

Total wrist fusion provides reliable pain relief and stability but eliminates wrist flexion and extension.

It is often preferred in high-demand patients with advanced arthrosis.

Total Wrist Arthroplasty

Total wrist replacement may preserve motion in carefully selected lower-demand patients.

Implant longevity and activity restrictions must be considered.

Physical Therapy

Physical therapy generally has a limited role before definitive treatment.

It may be useful after surgery for:

Edema control, finger motion, scar management, gradual restoration of wrist motion when permitted, and strengthening.

Follow-Up

Prognosis

Untreated disease may progress to:

Lunate collapse, carpal malalignment, and secondary degenerative wrist arthritis.

However, the clinical course is variable, and not every patient with radiographic progression develops severe disability.

Children

Children tend to have a more favorable prognosis because of greater potential for revascularization and remodeling.

Complications

Potential complications of progressive Kienböck disease include:

Increasing wrist pain, mechanical clicking, loss of grip strength, reduced range of motion, carpal collapse, and secondary wrist arthritis.

Surgical Complications

Depending on the procedure, complications may include:

Nonunion of an osteotomy or fusion, stiffness, hardware irritation, persistent pain, progression of arthritis, and need for later salvage surgery.

Patient Monitoring

Even when surgery is not initially performed, patients should be followed periodically.

Monitoring should assess:

Pain, grip strength, wrist range of motion, functional limitation, lunate sclerosis or collapse, carpal height, scaphoid rotation, and progression of arthritis.

Serial radiographs are useful for detecting structural progression, while MRI may be used when early disease activity or lunate viability remains uncertain.

Orthopaedic Surgery - Jones Fracture

Basics

A Jones fracture is a fracture involving the proximal fifth metatarsal, near the metaphyseal-diaphyseal junction of the foot.

Proximal fifth metatarsal fractures may occur acutely after trauma or develop gradually as a stress fracture.

Because prognosis and treatment vary substantially according to fracture location, these injuries are commonly divided into three anatomic zones.

Classification

Zone 1: Tuberosity Avulsion Fracture

Zone 1 fractures involve the fifth metatarsal tuberosity.

They usually do not extend into the fourth-fifth intermetatarsal articulation.

These injuries are commonly called avulsion fractures or pseudo-Jones fractures.

They often result from traction by the peroneus brevis tendon or lateral plantar fascia during an inversion injury.

Zone 2: True Jones Fracture

A true Jones fracture occurs at the metaphyseal-diaphyseal junction.

The fracture extends into the fourth-fifth intermetatarsal joint.

This location has a relatively vulnerable blood supply and therefore carries a greater risk of delayed union and nonunion than a Zone 1 avulsion fracture.

Zone 3: Proximal Diaphyseal Stress Fracture

Zone 3 fractures are located in the proximal fifth metatarsal diaphysis, distal to the classic Jones fracture region.

They frequently represent repetitive stress injuries rather than a single acute traumatic event.

These fractures can also have a substantial risk of delayed union or nonunion.

Prevention

Athletes who develop persistent pain over the lateral border of the foot should be evaluated early.

When a stress injury is suspected, timely imaging and activity modification may prevent progression from a stress reaction to a complete fracture.

Epidemiology

Fifth metatarsal fractures are common, particularly in physically active individuals.

Metatarsal fractures can occur at any age, with an average age of approximately 42 years reported in some series.

Frequency

The fifth metatarsal is the most commonly fractured metatarsal.

Approximately 63% of all metatarsal fractures have been reported to involve the fifth metatarsal.

Sex

Some series report a higher overall frequency of metatarsal fractures in females, although athletic Jones fractures are also common in young male athletes.

Athletic Population

Jones fractures are especially important in sports requiring repeated:

Running, jumping, cutting, acceleration, and change of direction.

Historical reports suggest that approximately 1.8% of professional football players may sustain a Jones fracture during their careers.

Risk Factors

Important risk factors include:

Athletic participation, repetitive high-impact activity, falls, direct trauma to the lateral foot, osteoporosis, and abnormal foot alignment.

Cavus Foot

A cavus or cavovarus foot increases loading along the lateral column of the foot and may predispose to fifth metatarsal stress injury or recurrent fracture.

Etiology

The mechanism varies according to fracture type.

Zone 1 Avulsion Fracture

These fractures commonly occur during an inversion or internal-rotation injury of the foot.

The sudden traction force at the fifth metatarsal base avulses the tuberosity.

Zone 2 Jones Fracture

A Jones fracture may result from:

Inversion, plantarflexion with forefoot loading, twisting injury, or repetitive athletic stress.

Zone 3 Diaphyseal Fracture

These injuries may occur from:

Repetitive stress, indirect twisting, or direct trauma.

Chronic stress fractures are particularly common in high-level athletes.

Diagnosis

Signs and Symptoms

Patients typically develop:

Pain, swelling, and focal tenderness along the lateral border of the foot near the base of the fifth metatarsal.

Weight Bearing

Walking often increases pain.

Athletic movements such as:

Running, jumping, cutting, or changing direction

may produce particularly severe symptoms.

Physical Examination

Palpation

There is usually point tenderness over the proximal fifth metatarsal.

The precise location of maximal tenderness can help distinguish a tuberosity avulsion from a true Jones fracture or more distal diaphyseal injury.

Swelling

Swelling and occasionally erythema or bruising may be present.

Weight-Bearing Examination

Patients commonly experience pain with standing or walking.

Some acute fractures prevent normal weight bearing entirely.

Foot Alignment

The examiner should evaluate for:

Cavus or cavovarus alignment, which increases mechanical stress along the lateral ray.

Imaging

Plain Radiographs

Initial imaging should include:

AP, lateral, and oblique radiographs of the foot.

These views help define:

Fracture location, displacement, comminution, and involvement of adjacent joints.

MRI

MRI is useful when:

Plain radiographs are normal or equivocal but clinical suspicion for a stress fracture remains high.

It can detect early marrow edema and stress reaction before a clear fracture line develops.

CT

CT may be helpful when evaluating:

Delayed union, suspected nonunion, postoperative healing, or bony union after previous fixation.

Pathophysiology

The region of the fifth metatarsal metaphyseal-diaphyseal junction has a relatively tenuous blood supply.

Watershed Region

This vascular watershed area contributes to the higher incidence of delayed union and nonunion in true Jones fractures.

For this reason, Zone 2 injuries require more cautious management than typical Zone 1 avulsion fractures.

Zone 3 stress fractures may also heal slowly because repetitive loading can overwhelm the local healing response.

Differential Diagnosis

Important alternatives include:

Lisfranc injury, fifth metatarsal stress fracture, cuboid fracture, peroneal tendon strain or tear, and lateral ankle sprain.

Lisfranc Injury

Pain extending into the midfoot, plantar bruising, or tenderness at the tarsometatarsal joints should raise concern for a Lisfranc injury.

Peroneal Tendon Injury

Peroneus brevis or longus tendon pathology can cause lateral foot pain and may mimic a fifth metatarsal fracture.

Treatment

Treatment depends on the fracture zone, displacement, chronicity, activity level, and patient expectations.

Zone 1 Tuberosity Avulsion Fracture

Most Zone 1 fractures are treated nonoperatively.

Weight Bearing

Weight bearing is generally permitted as tolerated, using:

A stiff-soled shoe, walking boot, splint, or short cast for comfort.

Healing

Clinical healing commonly occurs within approximately 6–12 weeks.

Radiographic union may lag behind clinical recovery.

Displacement

Even considerably displaced avulsion fragments may heal satisfactorily without surgery if joint congruity and function remain acceptable.

Symptomatic Nonunion

Nonunion is uncommon and often asymptomatic.

If a persistent painful nonunion occurs, options may include:

Fragment excision with reattachment of the peroneus brevis tendon or other reconstructive tendon procedures.

Zone 2 Jones Fracture

True Jones fractures require more cautious treatment because of their relatively high nonunion risk.

Nonoperative Treatment

In lower-demand patients with an acute fracture, treatment may consist of:

Strict non-weight-bearing immobilization in a below-knee cast or boot for approximately 6 weeks, followed by gradual protected weight bearing as healing progresses.

The total immobilization and protection period may extend for several additional weeks.

Return to Activity

Return to unrestricted athletic activity may require approximately 3–5 months with nonoperative management, depending on healing.

Chronic Stress Injury

Chronic or stress-related Jones fractures are less likely to heal predictably with casting alone.

These injuries are more likely to require operative fixation.

Zone 3 Proximal Diaphyseal Stress Fracture

Nonoperative treatment generally requires a prolonged period of non-weight bearing, often at least 6–8 weeks or longer, until progressive healing is demonstrated.

Because these fractures frequently represent chronic stress injuries, operative treatment is commonly considered in athletes or delayed unions.

Activity

Zone 1

Activity may progress according to pain and tolerance.

Zones 2 and 3

Patients are generally restricted from full weight bearing initially.

Progression to weight bearing depends on:

Symptoms, fracture type, radiographic healing, and whether operative fixation was performed.

Physical Therapy

Formal physical therapy is rarely necessary during the initial healing phase.

After union, rehabilitation may focus on:

Range of motion, strength, balance, proprioception, gait, and gradual return to sport.

Surgery

Indications

Surgical treatment may be considered for:

Competitive athletes, chronic stress fractures, delayed union, nonunion, recurrent fractures, or fractures requiring a faster and more predictable return to high-level activity.

Intramedullary Screw Fixation

The most common operation is percutaneous intramedullary screw fixation.

A screw is passed down the medullary canal of the fifth metatarsal to compress and stabilize the fracture.

Competitive Athletes

Competitive athletes frequently undergo early fixation because surgery may provide:

Higher union rates, earlier weight bearing, and faster return to sport than prolonged casting.

Postoperative Weight Bearing

Protected weight bearing may begin relatively early in selected surgically treated patients, sometimes after approximately 2 weeks, depending on fixation, symptoms, and surgeon protocol.

Return to Sport

Athletes may return when there is:

No pain or focal tenderness, satisfactory functional recovery, and convincing evidence of healing.

Return commonly occurs around 8–12 weeks or later after successful operative fixation.

Return based solely on time should be avoided.

Surgery for Zone 3 Fractures

Proximal diaphyseal stress fractures may also be treated with intramedullary screw fixation, particularly when:

The athlete requires earlier return, sclerosis is present, or previous nonoperative treatment has failed.

Bone grafting may occasionally be added in established nonunion.

Surgery for Zone 1 Avulsion Fracture

Surgery is rarely required.

For persistent symptomatic nonunion, the fragment may be excised and the peroneus brevis tendon reattached.

Follow-Up

Prognosis of Zone 1 Fractures

The prognosis for tuberosity avulsion fractures is excellent.

Most patients regain normal function with conservative treatment.

Prognosis of Jones Fractures

Jones fractures have a less predictable natural history because of the vulnerable local blood supply.

Older series reported nonunion or delayed-union rates as high as approximately 40–60% with nonoperative treatment, although outcomes vary according to fracture chronicity, patient selection, and treatment protocol.

Surgical Prognosis

Intramedullary fixation generally produces:

Higher rates of union and earlier return to activity, particularly in athletes.

Complications

Delayed Union

Healing may progress more slowly than expected, particularly in Zone 2 and Zone 3 injuries.

Nonunion

Persistent lack of healing is one of the most important complications.

Risk is increased by:

Poor blood supply, chronic stress injury, premature return to sport, smoking, inadequate immobilization, and recurrent loading.

Refracture

Refracture may occur, particularly in highly competitive athletes.

Risk increases if the patient returns to high-impact sport before biological healing is complete.

Hardware Failure

Intramedullary screws may occasionally:

Break, loosen, bend, or become symptomatic.

Prominent Hardware

Screw prominence may produce local irritation and occasionally require implant removal after complete fracture healing.

Return to Sport

Premature return to competition is associated with a higher risk of:

Persistent fracture, nonunion, and refracture, even after surgical fixation.

Return should therefore be based on a combination of:

Clinical examination, absence of pain and tenderness, functional testing, and imaging evidence of healing.

Patient Monitoring

Patients should undergo serial clinical and radiographic follow-up until fracture healing is established.

Follow-Up Interval

Evaluation at approximately monthly intervals may be appropriate during early healing, particularly for Zone 2 and Zone 3 fractures.

Delayed Union

Delayed union should be suspected when there is minimal radiographic progression by approximately 6–8 weeks, especially if focal pain persists.

Nonunion

A fracture may be considered an established nonunion when there is persistent pain and no meaningful progression toward healing over a prolonged period, often around 6 months, although modern definitions also take clinical and radiographic progression into account.

Long-Term Prevention

In recurrent or stress-related fractures, the clinician should evaluate contributing factors such as:

Cavovarus alignment, training errors, footwear, bone health, nutritional deficiency, and premature return to high-impact activity.

Correcting these factors may reduce the risk of another fracture.

Orthopaedic Surgery - Intertrochanteric Hip Fracture

Basics

An intertrochanteric hip fracture is an extracapsular fracture of the proximal femur located between the greater and lesser trochanters.

The greater or lesser trochanter may separate as an individual fracture fragment.

These injuries are also called trochanteric or pertrochanteric fractures.

Classification

Many classification systems have been proposed, but their reproducibility is limited.

For practical treatment purposes, intertrochanteric fractures are commonly divided into:

Stable and unstable fractures.

Stable Fractures

A stable fracture generally has:

An intact or adequately reconstructed posteromedial cortex and a preserved lateral femoral wall or buttress.

These features allow the fracture to resist excessive collapse after fixation.

Unstable Fractures

Features of instability include:

Posteromedial comminution, disruption of the lateral wall, reverse-obliquity fracture configuration, subtrochanteric extension, or substantial comminution.

These patterns are more likely to shorten, collapse into varus, or fail mechanically if the fixation construct is inadequate.

Prevention

Prevention is directed primarily toward improving bone health and reducing falls.

Bone Health

Measures may include:

Adequate calcium and vitamin D intake, appropriate osteoporosis screening and treatment, antiresorptive or anabolic therapy when indicated, and regular weight-bearing exercise.

Bisphosphonates are commonly used in appropriate patients with osteoporosis.

Fall Prevention

Fall-risk reduction in older adults may include:

Canes or walkers, balance and strength training, medication review, correction of visual impairment, improved lighting, handrails, removal of loose rugs, and other home modifications.

Hip Protectors

External hip protectors may be considered in selected frail or institutionalized patients at particularly high risk of falls.

Epidemiology

Intertrochanteric fractures are substantially more common in women than men, largely because of the greater prevalence of postmenopausal osteoporosis.

Older series report female-to-male ratios ranging from approximately 2:1 to 8:1.

Incidence

Historical annual incidence has been estimated at approximately:

63 per 100,000 women and 34 per 100,000 men.

Proportion of Hip Fractures

Intertrochanteric fractures account for approximately 40–50% of all hip fractures.

Age

Incidence increases sharply with advancing age because of:

Osteoporosis, frailty, impaired balance, and increasing frequency of falls.

Risk Factors

The major risk factors are:

Advanced age, osteoporosis, frailty, gait instability, previous falls, and any condition that increases fall risk.

Pathologic Fracture

Intertrochanteric fractures may occasionally occur through abnormal bone weakened by:

Primary bone tumors, metastatic disease, or other pathologic processes.

Etiology

Most intertrochanteric fractures result from a fall, particularly in older adults.

Motor vehicle collisions are a less common but important cause, particularly in younger patients.

Mechanism of Injury

Typical mechanisms include:

Direct impact over the greater trochanter or axial loading transmitted through the femur.

Muscular forces acting on the trochanters can further displace the fragments after the fracture occurs.

Associated Conditions

Common associated conditions include:

Osteoporosis and frailty.

High-energy injuries may also be accompanied by:

Other fractures, soft-tissue trauma, neurologic injury, or vascular injury in the affected limb.

Diagnosis

Signs and Symptoms

Presentation depends partly on fracture stability and displacement.

Stable or Minimally Displaced Fractures

Some patients may remain able to stand or even walk, although weight bearing usually produces pain.

Pain is typically located in the groin, proximal thigh, or lateral hip.

Unstable or Displaced Fractures

Patients typically have:

Severe pain, inability to walk, substantial limitation of hip motion, swelling, and bruising over the lateral hip or greater trochanter.

History

The classic history is an older adult who sustains a low-energy fall from standing height.

In younger patients, the mechanism is more often high energy.

The clinician should also ask about:

Previous hip pain, preinjury mobility, osteoporosis treatment, use of anticoagulants, cognitive status, and medical comorbidities.

Physical Examination

Limb Position

A displaced intertrochanteric fracture typically produces a leg that appears:

Shortened and externally rotated.

External rotation can be pronounced because the distal fragment rotates under the influence of muscular forces, including the iliopsoas.

Inspection

Examine for:

Swelling, bruising, deformity, skin compromise, and wounds.

Hip Examination

Movement of the hip is usually extremely painful.

Forceful range-of-motion testing should be avoided once fracture is suspected.

Ipsilateral Knee and Limb Examination

The knee and remainder of the lower extremity should be assessed for associated injury, particularly after high-energy trauma.

Neurovascular Examination

Distal motor function, sensation, pulses, and capillary refill should be documented.

Imaging

Plain Radiographs

Initial imaging generally includes:

AP pelvis, AP view of the affected hip, and cross-table lateral hip radiograph.

Full-Length Femur

A full-length femoral radiograph may be useful to identify:

Additional fractures, distal deformity, previous implants, or other abnormalities relevant to surgical planning.

Occult Fracture

If the history and examination strongly suggest a hip fracture but plain radiographs are negative, MRI is the preferred test for detecting an occult fracture.

CT may be used when MRI is unavailable or contraindicated.

Treatment

General Principles

Most intertrochanteric fractures are treated surgically because fixation permits:

Earlier mobilization, earlier weight bearing, improved pain control, and reduced complications of prolonged bed rest.

Preoperative Care

Patients should generally remain protected from unrestricted weight bearing until definitive stabilization.

Traction

Routine preoperative traction has not been shown to provide meaningful benefit and is generally unnecessary.

Medical Optimization

Because many affected patients are elderly and medically complex, perioperative management should address:

Fluid status, anemia, anticoagulation, cardiac and pulmonary disease, pain control, delirium risk, nutrition, and osteoporosis.

Surgery should proceed promptly once the patient is medically optimized.

Nursing Care

Pressure-Injury Prevention

Special attention should be given to avoiding pressure over the:

Sacrum and heels.

Frequent repositioning and appropriate padding are important.

Delirium Prevention

Older patients are at high risk for acute delirium.

Useful measures include:

Frequent reorientation, adequate pain control, preservation of sleep-wake cycles, early mobilization, ensuring access to glasses and hearing aids, adequate hydration, and minimizing unnecessary sedating medications.

Nonoperative Treatment

Nonoperative management is rarely selected.

It may be considered in patients who:

Were already nonambulatory, have extremely limited life expectancy, or have medical conditions that make surgery disproportionately hazardous.

These patients still require aggressive pressure care, analgesia, pulmonary hygiene, thrombosis prevention, and gentle mobilization when possible.

Surgery

After closed or open reduction, the fracture is stabilized internally.

The implant is chosen according to fracture geometry and stability.

Sliding Hip Screw

A sliding hip screw, also called a dynamic hip screw (DHS), consists of a lag screw placed into the femoral head and neck that slides within a barrel attached to a side plate.

Mechanism

Controlled sliding permits the fracture to:

Impact and compress during weight bearing, improving bony contact and promoting union.

Indications

A sliding hip screw is particularly useful for stable intertrochanteric fracture patterns with an intact lateral wall.

Lateral Buttress

For a sliding hip screw to function properly, the lateral femoral wall must provide a mechanical stop.

If the lateral wall is deficient, uncontrolled lateralization or collapse can occur.

Cephalomedullary Nail

An intramedullary hip fixation device, usually a cephalomedullary nail, is commonly used for unstable patterns.

Indications

Particularly important indications include:

Reverse-obliquity fractures, subtrochanteric extension, lateral wall disruption, and highly comminuted unstable fractures.

The intramedullary implant itself provides a more medial load-sharing construct and can act as a buttress against excessive collapse.

Lag Screw Position

The position of the cephalic lag screw or blade within the femoral head is critical for preventing fixation failure.

Tip-to-Apex Distance

The tip-to-apex distance (TAD) is calculated by adding the distance from the tip of the lag screw to the apex of the femoral head on both the AP and lateral radiographs, corrected for magnification.

A target of approximately 25 mm or less is commonly recommended.

Failure Risk

A TAD greater than approximately 25 mm is associated with an increased risk of screw cutout and fixation failure.

Central or inferior-central placement within the femoral head is generally preferred depending on implant design.

Quality of Reduction

Successful fixation also depends on obtaining:

Appropriate neck-shaft alignment, restoration of medial cortical support, avoidance of varus, and satisfactory rotational alignment.

Good reduction is at least as important as implant selection.

Arthroplasty

Hip replacement is not the routine treatment for most intertrochanteric fractures.

However, arthroplasty may occasionally be considered in patients with:

Extreme comminution, severe preexisting hip arthritis, failed previous fixation, or fracture patterns unlikely to be reconstructed reliably.

Physical Therapy

Early rehabilitation is essential after fixation.

Mobilization

Patients should be mobilized as soon as medically safe, often beginning on the first postoperative day.

Weight Bearing

In many older patients with stable fixation, weight bearing as tolerated is encouraged.

Restrictions may be necessary in selected unstable fractures or when fixation quality is suboptimal.

Assistive Devices

A:

Walker, crutches, or cane

may be used according to balance, strength, and preinjury mobility.

Rehabilitation

Many elderly patients require a period of:

Inpatient rehabilitation, skilled nursing care, or structured home therapy

before they regain sufficient strength and independence.

Follow-Up

Main Rehabilitation Goal

The primary goal after surgery is early restoration of safe mobility while minimizing complications associated with immobility.

Prognosis

Fracture union is generally reliable because the intertrochanteric region contains well-vascularized cancellous bone.

However, recovery of overall function depends heavily on the patient’s preinjury health and mobility.

Functional Recovery

Historical studies suggest that only approximately 50% of patients return completely to their previous functional level after an intertrochanteric hip fracture.

Loss of independence is common in frail older adults.

Mortality

One-year mortality after hip fracture is substantial and is driven largely by:

Advanced age, frailty, and coexisting medical disease rather than the fracture alone.

Historical reports describe rates ranging from approximately 14–36%.

Complications

Delirium

Acute changes in mental status are common in older hospitalized patients.

Prevention and early treatment of postoperative delirium are important components of care.

Venous Thromboembolism

Deep venous thrombosis and pulmonary embolism are important complications.

Appropriate thromboprophylaxis should be used according to individual bleeding and thrombotic risk.

Options may include:

Low-molecular-weight heparin, direct factor Xa inhibitors, aspirin in selected protocols, or other anticoagulants together with mechanical prophylaxis and early mobilization.

Fixation Failure

Mechanical failure may produce:

Excessive fracture collapse, shortening, varus deformity, screw migration, or cutout through the femoral head.

Risk Factors for Mechanical Failure

Important causes include:

Poor reduction, varus alignment, inadequate fixation in the femoral head, excessive tip-to-apex distance, unstable fracture geometry, and severe osteoporosis.

Intra-Articular Penetration

The cephalic screw or blade can penetrate the femoral head and enter the hip joint if fixation fails or the implant is positioned too deeply.

This complication often requires revision surgery.

Peri-Implant Fracture

Stress concentration around the fixation device may rarely contribute to a new femoral fracture.

Nonunion

Nonunion is uncommon, historically occurring in fewer than approximately 2% of cases, because the intertrochanteric region has a rich blood supply.

Osteonecrosis

Femoral-head osteonecrosis is also uncommon compared with intracapsular femoral-neck fractures because the fracture generally lies outside the hip capsule and does not usually disrupt the main blood supply to the femoral head.

Salvage of Failed Fixation

Failed fixation with painful deformity, nonunion, or severe post-traumatic arthritis may require:

Revision fixation or conversion to total hip arthroplasty, depending on bone quality and joint condition.

Patient Monitoring

Patients should be followed clinically and radiographically until fracture healing is established.

Radiographic Surveillance

Radiographs should assess:

Fracture alignment, degree of controlled collapse, lag screw or blade position, maintenance of fixation, callus formation, and union.

Follow-up commonly continues for at least 1 year in complex cases.

CT

If union is difficult to determine on plain radiographs or nonunion is suspected, CT can help evaluate persistent fracture lines and bridging bone.

Long-Term Care

Following fracture recovery, attention should also be directed toward preventing future fragility fractures through:

Osteoporosis assessment and treatment, vitamin D optimization, fall-prevention strategies, strength and balance training, and review of modifiable risk factors.

Orthopaedic Surgery - Intercondylar Elbow Fracture

Basics

An intercondylar elbow fracture is an intra-articular fracture of the distal humerus in which the fracture extends through the articular surface and may separate one or both distal humeral columns.

These injuries may occur alone or together with a supracondylar fracture component.

Because the elbow joint is directly involved, restoration of articular congruity, alignment, stability, and early motion is particularly important.

Classification

No single classification system is universally used.

Modern descriptions frequently use the term column rather than condyle because the medial and lateral columns of the distal humerus provide the structural framework for fixation.

Single-Column Fractures

Single-column fractures involve either the:

Medial column or lateral column.

Lateral-sided injuries are more common than medial-sided injuries.

Low Single-Column Fractures

These involve a smaller distal portion of the articular segment and may be relatively more stable.

High Single-Column Fractures

Higher fractures incorporate a larger portion of the trochlea and distal humeral column.

They are generally more unstable.

Milch Classification

The Milch system is based on whether the fracture line includes the lateral aspect of the trochlea.

Milch Type I

Milch Type I is broadly analogous to a lower single-column fracture.

Milch Type II

Milch Type II corresponds more closely to a higher single-column fracture and includes more of the trochlear region.

Bicolumn Fractures

Bicolumn fractures separate both the medial and lateral columns and usually extend through the distal humeral articular surface.

They are generally more complex and unstable than single-column fractures.

Jupiter-Mehne Descriptive Patterns

Common fracture configurations include:

T-shaped, Y-shaped, H-shaped, and lambda-shaped patterns.

The pattern is determined by how the fracture lines pass through the columns and articular surface.

Synonyms

Other terms include:

Unicondylar fracture, bicondylar fracture, single-column fracture, bicolumn fracture, and intra-articular distal humerus fracture.

Epidemiology

Intercondylar distal humeral fractures can occur at any age but are uncommon before skeletal maturity.

Single-column injuries are proportionally more frequent in children, whereas complex bicolumn fractures are more typical in adults.

Single-Column Fractures

These are uncommon, accounting for approximately 3–4% of distal humerus fractures in older series.

Bicolumn Fractures

Reported incidence varies considerably, historically ranging from approximately 5–62% of distal humerus fractures, depending on the population and classification system used.

Age Distribution

A bimodal pattern is typical.

Younger Patients

Younger patients, often male, usually sustain these injuries through high-energy trauma.

Older Patients

Older adults, particularly women with osteoporosis, may sustain a distal humeral fracture after a relatively low-energy fall.

Risk Factors

Major risk factors include:

High-energy trauma, osteoporosis, advanced age, and increased fall risk.

Etiology

Common mechanisms include:

Falls from height, falls onto an outstretched arm, motor vehicle collisions, pedestrian-versus-vehicle trauma, and direct blows to the elbow.

The force may be transmitted axially through the forearm or applied directly to the distal humerus.

Associated Conditions

Because these fractures may result from substantial trauma, associated injuries can include:

Neurapraxia, vascular injury, additional upper-extremity fractures, and polytrauma.

Diagnosis

Signs and Symptoms

Typical findings include:

Severe elbow pain, substantial swelling, deformity, and marked reduction or complete loss of elbow motion.

Neurologic Symptoms

Although less common, patients may also report:

Numbness, tingling, dysesthesia, or weakness.

These findings should raise concern for nerve injury.

Vascular Symptoms

Pallor, coolness, delayed capillary refill, or diminished pulses indicate possible vascular compromise and require urgent assessment.

Physical Examination

Because many injuries are high energy, the patient should undergo a complete trauma and upper-extremity evaluation.

Skin Examination

Determine whether the fracture is:

Open or closed.

Look for:

Lacerations, puncture wounds, skin tenting, abrasions, severe bruising, or threatened soft tissue.

Swelling

Marked swelling is common and may obscure normal bony landmarks.

Vascular Examination

Document:

Radial and ulnar pulses, capillary refill, hand temperature, skin color, and evidence of ischemia.

A pulseless or poorly perfused hand requires immediate attention.

Neurologic Examination

Motor and sensory function should be carefully documented in the distributions of the:

Ulnar, median, anterior interosseous, radial, and posterior interosseous nerves.

Ulnar Nerve

Test:

Finger abduction and adduction and sensation over the little finger.

The ulnar nerve is particularly important because of its close relationship to the medial epicondyle and operative field.

Median Nerve

Median nerve function can be assessed with:

Thumb opposition, finger flexion, and palmar sensation in the radial digits.

Anterior Interosseous Nerve

Ask the patient to form an “OK” sign using the thumb and index finger.

Weakness suggests anterior interosseous dysfunction.

Radial Nerve

Test:

Wrist extension, finger extension, and sensation over the dorsal first web space.

Posterior Interosseous Nerve

Finger and thumb MCP extension help assess posterior interosseous motor function.

Elbow Motion

Patients frequently cannot tolerate active or passive movement because of pain.

If motion is attempted, crepitus or gross instability may be apparent.

Forceful examination should be avoided.

Imaging

Plain Radiographs

Initial imaging includes:

AP and lateral radiographs of the elbow.

Views of the entire humerus or forearm should be obtained when the examination suggests associated injury.

Fat-Pad Signs

Subtle fractures may be associated with displacement of the anterior or posterior fat pads.

A visible posterior fat pad is particularly suspicious for an intra-articular fracture.

Specialized Views

A radiocapitellar view may help distinguish:

Radial head, capitellar, and other subtle lateral elbow fractures.

CT

CT is particularly useful for:

Severely comminuted fractures, partial-articular injuries, and preoperative planning.

Three-dimensional reconstruction can improve understanding of complex articular fracture anatomy.

Differential Diagnosis

Important alternatives or associated injuries include:

Humeral shaft fracture, supracondylar fracture, transcondylar fracture, elbow dislocation, elbow sprain, capitellar fracture, trochlear fracture, olecranon fracture, radial head fracture or dislocation, proximal forearm fracture, and Monteggia fracture-dislocation.

Treatment

General Principles

The main objectives are to:

Restore the articular surface, reconstruct the medial and lateral columns, provide stable fixation, and begin early elbow motion.

Most displaced intercondylar fractures are now treated surgically.

Initial Management

Acute care includes:

Rest, ice, elevation, analgesia, careful neurovascular monitoring, and immobilization in a well-padded splint.

Vascular Compromise

If the limb has a diminished or absent pulse, urgent reduction and stabilization should be performed.

If perfusion does not improve, vascular exploration or other urgent surgical intervention may be required.

Timing of Surgery

When operative fixation is indicated and the patient is medically stable, surgery is generally performed early after soft-tissue assessment, often within the first several days.

Single-Column Fractures

Nondisplaced Fractures

Rare nondisplaced fractures may be managed nonoperatively.

Close clinical and radiographic follow-up is necessary because displacement may occur.

Immobilization

Immobilization should generally be brief, often less than approximately 2 weeks, followed by controlled motion when stability allows.

Hinged Brace

A hinged elbow brace may be used to permit gradually increasing range of motion while protecting the healing fracture.

Displaced Single-Column Fractures

Displaced fractures generally require operative reduction and fixation.

Bicolumn Fractures

Most bicolumn intra-articular distal humerus fractures require surgical fixation because they are unstable and involve the articular surface.

Nonoperative Treatment

Nonoperative care is generally reserved for unusual circumstances such as:

Extreme medical frailty, severe osteoporosis with unreconstructable comminution, very low functional demand, or inability to tolerate surgery.

Activity

Early controlled motion is essential to prevent severe elbow stiffness.

Many surgeons try to avoid immobilization beyond approximately 10–14 days when fixation and soft tissues permit earlier motion.

Loading Restrictions

Heavy lifting and repetitive loading should be avoided until fracture healing is established.

Physical Therapy

Rehabilitation should begin as soon as the fracture is sufficiently stable.

Range of Motion

Carefully supervised flexion and extension exercises are important for recovering a functional elbow arc.

A commonly cited functional goal is approximately 100° of total motion, sufficient for many daily activities.

Hinged Bracing

A hinged brace may help control the arc of motion while protecting healing soft tissues and fixation.

Medication

Acute management may require:

Analgesics and perioperative antibiotic prophylaxis when surgery is performed.

Open fractures require appropriate urgent antibiotic coverage according to contamination and fracture severity.

Surgery

The operative strategy is tailored to the fracture pattern but generally follows the same principles:

Reconstruct the articular block, restore the columns, and provide sufficiently rigid fixation to permit early motion.

Surgical Approach

A posterior approach is commonly used.

Several methods of exposing the articular surface are available.

Olecranon Osteotomy

An olecranon osteotomy can provide excellent visualization of the distal humeral joint surface in complex fractures.

However, alternative triceps-sparing or triceps-reflecting approaches may also be used depending on surgeon preference and fracture pattern.

Articular Reconstruction

The joint surface is often reconstructed first with:

Lag screws, headless screws, or other interfragmentary fixation.

Once the articular block is restored, it is secured to the humeral shaft.

Dual-Column Plating

Modern fixation usually employs plates along both the medial and lateral columns.

Plate Configuration

Two widely used constructs are:

Orthogonal plating, in which the plates are roughly at right angles to each other.

Parallel plating, in which medial and lateral plates are positioned more directly opposite one another.

Both can provide strong fixation when properly applied.

Precontoured Plates

Modern distal humeral plates are often anatomically precontoured and may incorporate locking screw options.

These are particularly useful in osteoporotic or comminuted bone.

Bone Grafting

Bone graft or bone-graft substitute may occasionally be required when there is substantial metaphyseal bone loss or comminution.

Ulnar Nerve Management

The ulnar nerve should be carefully identified and protected.

Routine transposition is not universally necessary; management may involve either:

In situ decompression and protection or anterior transposition, depending on nerve tension, implant position, and surgeon preference.

Single-Column Fixation

Less complex single-column fractures may be treated with:

One or more screws, a small plate, or occasionally Kirschner wires in selected pediatric injuries.

Total Elbow Arthroplasty

In selected elderly patients with:

Severe articular comminution, poor bone quality, and low functional demand, primary total elbow arthroplasty may be considered instead of fracture reconstruction.

This approach is most appropriate when reliable internal fixation is unlikely.

Follow-Up

Prognosis

Despite the technical difficulty of these injuries, modern fixation techniques can produce good functional results.

Historical series have reported approximately 75% good-to-excellent outcomes even among complex fractures.

Range-of-Motion Outcome

A commonly accepted useful postoperative arc is approximately:

15–30° short of full extension to 120–130° of flexion.

Some permanent loss of terminal motion is common.

Complications

Loss of Motion

Elbow stiffness is the most common complication.

Patients frequently lose approximately:

10–20° of extension and 10–20° of flexion, although losses vary widely.

Nonunion

Failure of fracture healing may occur, especially with:

Severe comminution, poor fixation, bone loss, infection, or impaired biology.

Malunion

Malalignment of the distal humerus can result in:

Loss of motion, deformity, instability, or altered elbow mechanics.

Post-Traumatic Arthritis

Damage to the articular cartilage or imperfect restoration of the joint surface may lead to degenerative arthritis.

Loss of Fixation

Hardware failure or secondary displacement may occur in osteoporotic or highly comminuted fractures.

Symptomatic Hardware

Prominent plates or screws may cause irritation and occasionally require removal after fracture healing.

Osteonecrosis

Rarely, disrupted blood supply to an articular fragment may produce osteonecrosis.

Neurovascular Injury

Nerve or vascular structures can be injured by the original trauma or during surgery.

Ulnar Neuropathy

Ulnar nerve symptoms are particularly common after distal humeral fracture and fixation.

Patients may develop:

Numbness in the ulnar digits, intrinsic hand weakness, or neuropathic pain.

Infection

Superficial or deep infection may occur, with greater risk in open fractures or extensive soft-tissue injury.

Heterotopic Ossification

Ectopic bone formation around the elbow may restrict motion and contribute to stiffness.

Patient Monitoring

During the acute period and after surgery, patients should be monitored carefully for:

Neurovascular compromise, worsening swelling, compartment syndrome, wound problems, and loss of fixation.

Postoperative Follow-Up

Close follow-up is necessary to monitor:

Fracture healing, implant position, elbow stability, nerve function, and recovery of range of motion.

Early recognition of stiffness allows rehabilitation to be modified before a fixed contracture develops.