Orthopaedic Surgery - Sever Disease

Basics

Sever disease, also called:

Calcaneal apophysitis

is a common cause of:

Posterior heel pain in growing children.

The pain arises from repetitive stress across the:

Calcaneal apophysis or growth plate.

Nature of the Condition

Sever disease is considered a form of:

Traction apophysitis

or historically an:

Osteochondrosis

in which the developing cartilage and bone of the calcaneal apophysis become painful under repetitive mechanical loading.

Natural History

The condition is:

Self-limited.

Symptoms resolve as the:

Calcaneal growth plate matures and eventually closes.

It does not cause permanent structural damage.

Laterality

Sever disease may be:

Unilateral

or

Bilateral.

Bilateral involvement is relatively common.

Epidemiology

Sever disease occurs most often in:

Preadolescent children

during periods of rapid growth.

Historical estimates suggest that it affects approximately:

5–10% of preadolescents.

Sex

Boys have historically been reported to be affected more often than:

Girls

although the condition occurs in both sexes.

Typical Age

The classic patient is an active child approximately:

9–12 years old

although the precise age varies with:

Skeletal maturity

and timing of the growth spurt.

Risk Factors

Important risk factors include:

Running sports

Jumping activities

Rapid growth

High training volume

and repetitive loading of the:

Heel.

Genetics

There is no recognized:

Genetic predisposition

to Sever disease.

Etiology

The:

Achilles tendon

inserts near the calcaneal apophysis.

During periods of rapid growth, the apophysis may be relatively vulnerable to:

Repetitive traction forces.

Achilles Tendon Traction

Tension generated by the:

Gastrocnemius–soleus complex

and Achilles tendon repeatedly loads the developing:

Calcaneal apophysis.

This is particularly important during:

Running

Jumping

and

Sports involving repeated acceleration.

Impact Loading

Heel impact during athletic activity produces additional stress across the:

Calcaneus

and

Apophysis.

The combination of:

Achilles traction

and

Repetitive impact

contributes to symptoms.

Growth Spurt

During a rapid growth phase, the bones may lengthen faster than the:

Muscle-tendon units

adapt.

This can increase tension in the:

Achilles tendon

and further stress the calcaneal apophysis.

Diagnosis

Sever disease is primarily a:

Clinical diagnosis.

The diagnosis is based on:

Age

Activity pattern

Location of pain

and

Characteristic examination findings.

Signs and Symptoms

Pain usually begins:

Gradually

without a specific traumatic event.

Pain Location

The pain is located at the:

Posterior aspect of the heel

over the calcaneal apophysis.

It is typically:

Below the Achilles tendon insertion

rather than on the:

Plantar surface of the foot.

Activity Relationship

Pain is usually worsened by:

Running

Jumping

and other impact activities.

Symptoms may be particularly noticeable:

After activity.

Rest

Pain improves with:

Prolonged rest

or temporary reduction in:

Sports participation.

Duration

Symptoms may recur for:

Several months

during the growth period.

The intensity often fluctuates according to:

Activity level.

Bilateral Symptoms

Either one or both heels may be involved.

Children with bilateral symptoms frequently report alternating severity between:

Right and left sides.

Physical Examination

The child often points directly to or grasps the:

Posterior heel

when describing the painful area.

Calcaneal Squeeze Test

Pain can usually be reproduced by:

Medial and lateral compression of the calcaneus

near the apophysis.

This is often referred to as the:

Calcaneal squeeze test.

Tenderness

Tenderness is generally localized to the:

Posterior calcaneal apophysis.

The pain is usually uncomfortable but not:

Exquisitely severe.

Marked or disproportionate tenderness should raise concern for another diagnosis.

Dorsiflexion

Passive ankle dorsiflexion may cause a:

Mild increase in symptoms

because it tensions the:

Achilles tendon.

Swelling

Visible swelling is usually:

Absent.

This differs from conditions such as:

Osgood–Schlatter disease

where a prominent apophyseal swelling may develop.

Gait

Children with more severe symptoms may develop:

Antalgic gait

or avoid placing the heel fully on the ground.

Some may preferentially:

Toe walk

to reduce heel impact.

Laboratory Tests

Routine laboratory testing is:

Not required.

Electrolytes and Vitamin D

Sever disease is not typically associated with abnormalities in:

Electrolytes

or

Vitamin D.

Laboratory evaluation should be reserved for patients in whom another metabolic or inflammatory disorder is suspected.

Imaging

Plain Radiographs

Radiographs are usually:

Not necessary

when the history and examination are classic.

There is no specific radiographic finding that confirms:

Sever disease.

Normal Calcaneal Apophysis

The normal developing calcaneal apophysis may appear:

Sclerotic

Irregular

and

Multipartite.

These findings are normal developmental appearances and should not be mistaken for:

Diagnostic evidence of disease.

Role of Radiographs

Radiographs may be obtained when symptoms are:

Atypical

Unilateral and severe

Persistent

or associated with concern for:

Fracture

Bone lesion

or

Infection.

MRI

MRI is rarely required.

In prolonged symptomatic cases, MRI may demonstrate:

Bone marrow edema

within or around the:

Calcaneal apophysis.

Pathological Findings

There is no characteristic pathological specimen because:

Biopsy and surgery are not indicated.

The condition reflects a temporary mechanical stress response of the:

Developing apophysis.

Differential Diagnosis

Important alternative diagnoses include:

Retrocalcaneal bursitis

Achilles tendinopathy

Plantar fasciitis

Calcaneal stress fracture

Calcaneal osteomyelitis

Unicameral bone cyst

Inflammatory enthesitis

Retrocalcaneal Bursitis

Retrocalcaneal bursitis produces more localized tenderness near the:

Anterior aspect of the Achilles insertion.

It is seen more frequently in:

Older adolescents

and

Adults.

Achilles Tendinopathy

Achilles tendinopathy causes pain primarily within the:

Tendon itself.

Associated findings may include:

Tendon thickening

Swelling

and occasionally:

Crepitus with ankle movement.

Plantar Fasciitis

Plantar fasciitis causes pain on the:

Plantar-medial heel

rather than the posterior calcaneus.

It is much more common in:

Adults.

Calcaneal Stress Fracture

A calcaneal stress fracture may also produce:

Heel pain

and a positive squeeze test.

Concern should increase when pain is:

Progressive

Present at rest

or associated with substantially reduced ability to:

Bear weight.

Calcaneal Osteomyelitis

Calcaneal osteomyelitis is uncommon but important.

Features suggesting infection include:

Fever

Marked tenderness

Systemic illness

Night pain

or elevated:

Inflammatory markers.

Unicameral Bone Cyst

A unicameral bone cyst of the calcaneus may be detected incidentally or after:

Persistent pain

or

Pathological fracture.

Radiographs help identify this condition.

Inflammatory Enthesitis

Inflammatory disorders such as:

Spondyloarthritis

can produce heel pain at tendon or fascia attachment sites.

These diagnoses should be considered when heel pain is associated with:

Morning stiffness

Other joint symptoms

Back pain

or systemic inflammatory features.

Treatment

The mainstay of treatment is:

Conservative management.

Activity Modification

Temporary reduction of painful:

Running

Jumping

and

High-impact sports

is often sufficient.

Complete restriction from all physical activity is usually unnecessary.

Rest

Relative rest should be guided by:

Symptoms.

The child may continue activities that do not produce substantial pain or:

Limping.

Stretching

Stretching of the:

Gastrocnemius

Soleus

and

Achilles tendon

is often helpful.

Stretching may be performed:

Before and after activity.

Ice

Ice may provide symptomatic relief after:

Sports

or during periods of:

Increased pain.

Footwear

Supportive shoes with good:

Heel cushioning

can reduce repetitive impact.

Heel Cups

Useful inserts include:

Heel cups

Gel heel pads

or other cushioned:

Heel lifts.

These reduce pressure and traction across the:

Calcaneal apophysis.

Immobilization

For severe or persistent symptoms that do not improve with simpler measures, short-term immobilization in a:

Walking boot

or occasionally a:

Cast

may be considered.

Time and Maturity

The most important elements in recovery are:

Time

and

Skeletal maturation.

Symptoms eventually resolve as the:

Calcaneal apophysis closes.

Physical Therapy

Physical therapy may be useful when the child needs additional assistance with:

Calf stretching

Achilles flexibility

Strengthening

or correction of activity-related movement patterns.

Medication

Symptomatic medication may include:

NSAIDs

or

Acetaminophen

when appropriate.

These medications provide:

Pain relief

but do not alter the natural history of the condition.

Surgery

Surgery is:

Never indicated

for uncomplicated Sever disease.

There is no role for:

Apophyseal excision

Fixation

or other operative treatment.

Follow-Up

Follow-up may be arranged:

As needed

for persistent symptoms, education, or diagnostic uncertainty.

Patient Education

Families should understand that the condition is:

Benign

Self-limited

and related to:

Growth and repetitive mechanical loading.

This helps reduce unnecessary anxiety and allows the child to participate in:

Self-management.

Return to Sports

Return to sport can occur gradually when the child can:

Walk without pain

Run without limping

Jump comfortably

and tolerate activity without significant:

Post-exercise heel pain.

Prognosis

The prognosis is:

Excellent.

Sever disease resolves with:

Skeletal maturity.

Long-Term Outcome

Unlike some traction apophysitis disorders, Sever disease does not usually leave:

Persistent deformity

or

Long-term functional impairment.

Recurrence

Symptoms may recur repeatedly during:

Childhood or early adolescence

especially during periods of:

Rapid growth

or increased:

Sports participation.

Complications

There are essentially no permanent complications.

The main difficulty is:

Recurrent activity-related pain

during the period before the growth plate closes.

Key Principle

Sever disease is calcaneal apophysitis causing posterior heel pain in active, growing children, typically during the preadolescent growth spurt.

The diagnosis is primarily:

Clinical, with posterior calcaneal tenderness and pain on heel squeeze.

Radiographs are usually unnecessary because the normal calcaneal apophysis can appear:

Sclerotic, irregular, and fragmented.

Treatment consists of:

Activity modification, Achilles and calf stretching, ice, supportive cushioned footwear, heel cups, and occasional short-term immobilization, while:

Surgery has no role.

The condition ultimately:

Resolves completely with skeletal maturity.

Orthopaedic Surgery - Seronegative Spondyloarthropathies

Basics

Seronegative spondyloarthropathies, now more commonly termed:

Spondyloarthritis (SpA)

are a group of related inflammatory disorders characterized by varying combinations of:

Axial spinal inflammation

Sacroiliitis

Peripheral arthritis

Enthesitis

and

Extra-articular manifestations.

Seronegative Nature

These conditions were historically called:

Seronegative

because patients generally lack the typical:

Rheumatoid factor

associated with rheumatoid arthritis.

Antinuclear antibodies are also usually not a defining feature.

However, negative RF or ANA testing alone does:

Not establish the diagnosis.

Enthesitis

A characteristic feature is inflammation of the:

Enthesis

which is the site where a:

Tendon

Ligament

or

Joint capsule

attaches to bone.

For this reason, these diseases have historically also been described as:

Enthesopathies.

Major Disorders

The spondyloarthritis family includes:

Ankylosing spondylitis / radiographic axial spondyloarthritis

Reactive arthritis

Psoriatic arthritis

Enteropathic or inflammatory bowel disease-associated arthritis

as well as other forms of:

Axial and peripheral spondyloarthritis.

Prevention

The underlying inflammatory disease usually cannot be:

Prevented.

However, appropriate treatment and long-term follow-up may reduce complications such as:

Joint contractures

Spinal deformity

Functional limitation

and selected:

Cardiac or pulmonary complications.

Epidemiology

Many spondyloarthropathies begin before:

40 years of age.

Symptoms may first appear during:

Adolescence

or

Young adulthood.

Sex

Axial disease, particularly classic ankylosing spondylitis, has historically been recognized more often in:

Men.

Older studies suggested a male-to-female ratio of approximately:

2–3:1.

Women may have less radiographic axial damage and historically were more likely to experience:

Delayed diagnosis.

HLA-B27 Distribution

The prevalence of:

HLA-B27

varies considerably among different ancestral populations.

Historical estimates include approximately:

Up to 10% in some White populations

Around 3% in African Americans

Very low prevalence in many sub-Saharan African populations

and substantially higher frequencies in some:

Indigenous populations.

Risk Factors

Important risk factors include:

HLA-B27 positivity

Family history of spondyloarthritis

Young age at symptom onset

and, for some manifestations,

Male sex.

Associated Disease-Specific Risks

Additional associations include:

Psoriasis

Inflammatory bowel disease

Recent gastrointestinal infection

Recent genitourinary infection.

Genetics

HLA-B27 has a strong association with:

Ankylosing spondylitis

and a weaker association with several other forms of:

Spondyloarthritis.

HLA-B27 and Ankylosing Spondylitis

A large proportion of patients with classic ankylosing spondylitis are:

HLA-B27 positive.

Historical estimates approach:

90%

in some predominantly European-derived populations.

HLA-B27 Is Not Diagnostic

Most people who carry HLA-B27 do:

Not develop ankylosing spondylitis.

Therefore, HLA-B27 should be interpreted together with:

Symptoms

Physical findings

Imaging

and

Family history.

Pathogenesis

Spondyloarthritis reflects an interaction between:

Genetic susceptibility

and

Environmental or immunologic triggers.

Infectious Triggers

Reactive arthritis may follow infection with organisms such as:

Chlamydia trachomatis

Salmonella

Shigella

Yersinia

and

Campylobacter.

Molecular Mimicry

One proposed mechanism is that bacterial antigens may trigger an immune response that cross-reacts with:

Host tissues

in genetically susceptible individuals.

The exact immunopathogenesis is more complex than a single antigenic mechanism.

Associated Conditions

Extra-articular manifestations may include:

Acute anterior uveitis

Aortic root or valvular disease

Inflammatory bowel disease

Pulmonary fibrosis in advanced disease

and other systemic inflammatory manifestations.

Diagnosis

Diagnosis is based on the overall pattern of:

Inflammatory back pain

Sacroiliitis

Peripheral arthritis

Enthesitis

Dactylitis

Skin or nail disease

Bowel disease

Uveitis

and appropriate:

Imaging and laboratory findings.

Ankylosing Spondylitis

Classic ankylosing spondylitis typically presents with:

Inflammatory back or buttock pain

Sacroiliitis

Progressive spinal stiffness

and

Enthesitis.

Inflammatory Back Pain

Characteristic features include:

Insidious onset before age 40–45

Morning stiffness

Improvement with exercise

Limited improvement with rest

and sometimes:

Night pain.

Uveitis

Acute anterior uveitis may occur and typically presents with:

Painful red eye

Photophobia

and

Blurred vision.

This requires prompt:

Ophthalmologic assessment.

Reactive Arthritis

Reactive arthritis usually follows a:

Genitourinary

or

Gastrointestinal infection.

Classic Triad

The historical triad consists of:

Urethritis or cervicitis

Conjunctivitis

and

Arthritis.

However, many patients do:

Not develop the complete triad.

Additional Reactive Arthritis Findings

Other manifestations include:

Heel pain from enthesitis

Dactylitis

Oral ulcers

Circinate balanitis

and

Keratoderma blennorrhagicum.

Psoriatic Arthritis

Psoriatic arthritis occurs in a subset of patients with:

Psoriasis.

It can involve:

Peripheral joints

Entheses

Digits

and the:

Axial skeleton.

Typical Joint Pattern

The small joints of the hands and feet may be involved, particularly the:

Distal interphalangeal joints.

Nail Findings

Associated nail changes include:

Nail pitting

Onycholysis

and other psoriatic nail dystrophy.

Dactylitis

Diffuse swelling of an entire finger or toe produces a:

Sausage digit

and is highly characteristic of:

Psoriatic arthritis.

Enteropathic Arthritis

Enteropathic arthritis occurs in association with:

Crohn disease

or

Ulcerative colitis.

Axial Pattern

Axial disease may resemble:

Ankylosing spondylitis

with:

Sacroiliitis

and

Inflammatory back pain.

Peripheral Pattern

Peripheral disease often affects:

Large weight-bearing joints

such as the:

Hips

and

Knees.

It may be:

Asymmetric.

Gastrointestinal Symptoms

Underlying inflammatory bowel disease may produce:

Abdominal cramping

Abdominal pain

Diarrhea

Rectal bleeding

Weight loss

and

Dehydration.

Laboratory Tests

No single laboratory test confirms all forms of:

Spondyloarthritis.

Rheumatoid Factor

Rheumatoid factor is usually:

Negative.

A positive result does not absolutely exclude SpA, but strong seropositivity may suggest an alternative or overlapping diagnosis.

Antinuclear Antibodies

ANA testing is generally:

Not diagnostic

for spondyloarthritis.

It is more useful when considering diseases such as:

Systemic lupus erythematosus.

HLA-B27

HLA-B27 testing may support the diagnosis when the clinical probability is:

Intermediate or high.

It has limited value as a:

General population screening test.

Inflammatory Markers

ESR and CRP may be:

Elevated

particularly with active disease.

However, normal inflammatory markers do:

Not exclude spondyloarthritis.

Imaging

Plain Radiographs

Initial radiographic evaluation of suspected axial disease may include:

AP pelvis

and appropriate views of the:

Lumbar or thoracolumbar spine.

Symptomatic peripheral joints should also be imaged when indicated.

Sacroiliac Joints

Radiographs may demonstrate:

Erosions

Subchondral sclerosis

Joint-space narrowing

and eventually:

Ankylosis.

MRI

MRI can identify:

Active sacroiliitis

before definite structural abnormalities appear on:

Plain radiographs.

Important MRI findings include:

Bone marrow edema

and

Osteitis

near the sacroiliac joint.

CT

CT demonstrates structural sacroiliac changes well, including:

Erosions

Sclerosis

and

Ankylosis.

However, its radiation exposure limits routine use compared with:

MRI.

Ankylosing Spondylitis Imaging

Radiographic findings may include:

Bilateral sacroiliitis

Vertebral body squaring

Marginal syndesmophytes

and progressive:

Spinal ankylosis.

Bamboo Spine

Advanced bridging syndesmophytes may produce the classic appearance known as:

Bamboo spine.

Hip Disease

Severe hip involvement may lead to:

Joint-space loss

Protrusio

and secondary:

Arthritic destruction.

Reactive Arthritis Imaging

Reactive arthritis may demonstrate:

Sacroiliitis

which can be:

Asymmetric.

Spinal involvement is variable.

Psoriatic Arthritis Imaging

Typical findings include:

DIP joint involvement

Erosions

Bone proliferation

Joint ankylosis

and severe forms of:

Osteolysis.

Pencil-in-Cup Deformity

A characteristic advanced finding is:

Pencil-in-cup deformity

in which one bone end becomes tapered while the adjacent articular surface becomes:

Cup shaped.

Enteropathic Arthritis Imaging

Axial imaging findings may resemble those of:

Ankylosing spondylitis.

Trauma in Ankylosed Spine

Patients with advanced ankylosing spondylitis require special caution after:

Even relatively minor trauma.

The rigid ankylosed spine behaves biomechanically like a:

Long bone

and is particularly vulnerable to unstable fractures.

Occult Fractures

Plain radiographs may miss:

Nondisplaced fractures

in an ankylosed spine.

Therefore, a patient with significant pain after trauma may require:

CT

or

MRI.

Epidural Hematoma

MRI is particularly useful when there is concern for:

Epidural hematoma

or

Neurologic compression.

Pathological Findings

Characteristic inflammatory abnormalities include:

Enthesitis

and

Synovitis.

Enthesopathy

Chronic inflammation at ligament and tendon insertions may lead to:

Erosion

followed by:

Reactive bone formation

and eventual:

Ankylosis.

Extra-Articular Pathology

Depending on the specific disorder, other pathological changes may include:

Colitis

Aortitis

and, in advanced disease,

Pulmonary fibrosis.

Differential Diagnosis

Important alternatives include:

Rheumatoid arthritis

Mechanical low-back pain

Degenerative spine disease

Infectious sacroiliitis

Lyme arthritis

Fibromyalgia

and other inflammatory arthritides.

Treatment

Treatment should be individualized according to whether disease is predominantly:

Axial

Peripheral

or associated with:

Psoriasis

Uveitis

or

Inflammatory bowel disease.

General Measures

Patients should be encouraged to maintain:

Regular physical activity

Good posture

Spinal mobility

and

Joint range of motion.

Exercise

Low-impact exercises are generally preferred, including:

Walking

Swimming

and other aerobic conditioning.

Postural Training

Postural exercises are particularly important in axial disease to reduce progressive:

Flexion deformity

and maintain:

Thoracic expansion.

Sleeping Position

Patients with ankylosing spondylitis have historically been advised to use:

Supportive sleeping surfaces

and avoid prolonged positions that reinforce:

Spinal flexion.

Contact Sports

Patients with advanced spinal ankylosis should avoid activities with a high risk of:

Collision or spinal trauma.

Physical Therapy

Physical therapy may be required to maintain:

Spinal mobility

Peripheral joint motion

Strength

Posture

and

Cardiorespiratory conditioning.

Contracture Prevention

Regular stretching and range-of-motion exercises help prevent:

Hip

Knee

and

Spinal contractures.

Medication

NSAIDs

NSAIDs are commonly used as first-line treatment for:

Pain

Stiffness

and

Inflammatory symptoms.

Conventional Disease-Modifying Drugs

Agents such as:

Sulfasalazine

may be useful for:

Peripheral arthritis.

Methotrexate may be useful in selected patients, particularly with:

Peripheral psoriatic arthritis.

These drugs are generally much less effective for purely:

Axial disease.

Biologic Therapy

Patients with persistent active disease may require biologic or targeted therapy such as:

TNF inhibitors

IL-17 pathway inhibitors

or other agents selected according to:

Disease phenotype

and associated conditions.

Uveitis Treatment

Acute anterior uveitis may require:

Topical corticosteroid eye drops

and other ophthalmologic treatment.

Management should be supervised by an:

Ophthalmologist.

Surgery

Surgery is reserved for:

Severe structural joint or spinal disease.

Total Hip Arthroplasty

Severe hip arthritis may require:

Total hip replacement.

This can substantially improve:

Pain

and

Mobility.

Spinal Deformity Surgery

Severe fixed:

Cervical

Thoracic

or

Lumbar deformity

may occasionally require corrective:

Spinal osteotomy

and stabilization.

Fracture Surgery

Spinal fractures in patients with an ankylosed spine are frequently:

Unstable

and often require:

Long-segment surgical fixation.

Follow-Up

Patients should be monitored by a multidisciplinary team that may include:

Rheumatologists

Physical therapists

Orthopaedic surgeons

Ophthalmologists

and other specialists according to systemic involvement.

Monitoring Frequency

Patients with active disease may be reviewed approximately every:

3–6 months

with the interval individualized according to:

Disease activity

Medication

and

Complications.

Prognosis

Prognosis varies according to:

Specific diagnosis

Disease activity

Axial involvement

Peripheral joint damage

and response to:

Treatment.

Ankylosing Spondylitis Prognosis

In axial disease, long-term outcome depends on:

Rate of structural progression

and degree of:

Spinal and hip involvement.

Modern therapy can substantially improve:

Symptoms

and

Function.

Complications

Cardiac Disease

Possible cardiac complications include:

Aortic root inflammation

and

Aortic insufficiency.

Conduction abnormalities may also occur in advanced disease.

Pulmonary Disease

Severe long-standing ankylosing spondylitis can occasionally cause:

Upper-lobe pulmonary fibrosis

and restriction related to reduced:

Chest-wall mobility.

Gastrointestinal Complications

Patients with inflammatory bowel disease may develop complications including:

Fistula formation

Stricture

Bleeding

or

Perforation.

Vertebral Fracture

Patients with advanced ankylosing spondylitis are at increased risk of:

Cervical and thoracolumbar fractures

even after:

Low-energy trauma.

Neurologic Injury

These fractures may result in:

Spinal cord injury

or

Epidural hematoma

and therefore require urgent assessment.

Contractures

Chronic inflammation and reduced movement may produce:

Hip flexion contracture

Spinal stiffness

and loss of:

Peripheral joint motion.

Patient Monitoring

Long-term follow-up should evaluate:

Pain

Morning stiffness

Spinal mobility

Peripheral joint involvement

Enthesitis

Uveitis

Skin disease

Bowel symptoms

and treatment-related adverse effects.

Key Principle

Seronegative spondyloarthropathies, now commonly grouped under spondyloarthritis, are inflammatory disorders characterized by varying combinations of:

Sacroiliitis, axial inflammation, peripheral arthritis, enthesitis, dactylitis, and extra-articular disease.

The major disorders include:

Ankylosing spondylitis, reactive arthritis, psoriatic arthritis, and inflammatory bowel disease-associated arthritis.

HLA-B27 is an important:

Genetic association, but it is neither necessary nor sufficient for diagnosis.

Treatment emphasizes:

Regular exercise and physical therapy, NSAIDs, appropriate disease-modifying or biologic therapy, and management of extra-articular manifestations, while surgery is reserved for:

Advanced joint destruction, severe spinal deformity, or unstable fractures of an ankylosed spine.

Orthopaedic Surgery - Septic Knee

Basics

A septic knee is:

An infection of the synovial lining and joint space of the knee.

It is most commonly caused by:

Bacteria

and represents an:

Orthopaedic emergency

because untreated infection can rapidly destroy:

Articular cartilage

and lead to permanent joint dysfunction.

Predisposing Factors

Important predisposing conditions include:

Pre-existing arthritis

Intravenous drug use

Alcohol misuse

Corticosteroid therapy

and other causes of:

Immunosuppression.

Epidemiology

Septic arthritis of the knee is:

Common among native-joint infections.

It may occur in:

Infants

Children

Adults

and

Older adults.

In adults, the knee is one of the:

Most frequently affected joints.

Risk Factors

Important risk factors include:

Bacteremia

Intravenous drug use

Alcohol misuse

Recent trauma

Previous knee surgery

Recent joint injection or aspiration

HIV infection

Diabetes mellitus

Corticosteroid use

Other immunocompromised states

Pre-existing inflammatory or degenerative joint disease

Pathogenesis

Infection may reach the knee through:

Hematogenous spread

Direct inoculation

or

Contiguous extension from nearby infection.

Hematogenous Spread

Because the synovium is:

Highly vascular

bacteria circulating in the bloodstream can seed the:

Knee joint.

This is a common mechanism in:

Native-joint septic arthritis.

Direct Inoculation

Direct introduction of organisms may occur after:

Trauma

Surgery

Arthrocentesis

or

Intra-articular injection.

Etiology

The most common causative organism is:

Staphylococcus aureus.

Other Organisms

Additional organisms include:

Streptococcus species

Streptococcus pneumoniae

Neisseria gonorrhoeae

Neisseria meningitidis

Salmonella species

Brucella species

and, historically in young children,

Haemophilus influenzae.

Haemophilus influenzae

Haemophilus influenzae type b was historically an important cause of septic arthritis in:

Infants and young children.

Its incidence has fallen substantially following widespread:

Hib vaccination.

Diagnosis

Diagnosis is based on:

Clinical examination

Synovial fluid aspiration

Laboratory testing

and, when necessary,

Imaging.

The most important diagnostic procedure is:

Knee aspiration.

Signs and Symptoms

Common symptoms include:

Knee swelling

Pain

Pain with movement

Difficulty bearing weight

and occasionally:

Fever.

Joint Swelling

The joint capsule may become:

Distended

and

Fluctuant

because of a large:

Effusion.

Pain

Pain is typically aggravated by:

Active movement

Passive range of motion

and

Weight bearing.

Systemic Features

Patients may have:

Fever

Malaise

or

Leukocytosis.

However, systemic signs may be absent, particularly in:

Older

Immunocompromised

or partially treated patients.

Physical Examination

The key findings are:

Joint effusion

Painful range of motion

and

Restricted motion.

Effusion

A significant:

Intra-articular effusion

is commonly present.

Pain With Short-Arc Motion

Marked pain with even:

Small arcs of passive motion

strongly suggests an intra-articular inflammatory process such as:

Septic arthritis.

Erythema

Overlying erythema may be:

Absent

because the knee joint lies beneath several layers of:

Soft tissue.

Its absence does not exclude infection.

Warmth and Tenderness

The knee may demonstrate:

Warmth

Diffuse tenderness

and

Protective muscle spasm.

Laboratory Tests

Peripheral White Blood Cell Count

CBC may demonstrate:

Leukocytosis

with a:

Left shift.

However, a normal peripheral WBC count does not exclude:

Septic arthritis.

ESR

The:

Erythrocyte sedimentation rate

is commonly elevated.

It is useful as a supportive marker and may help monitor:

Treatment response.

C-Reactive Protein

CRP is also commonly elevated and is particularly useful because it:

Rises and falls more rapidly than ESR.

Serial measurements can assist in assessing:

Clinical improvement.

Synovial Fluid Aspiration

Joint aspiration is the:

Primary diagnostic test.

The aspirate should be sent for:

Cell count

Differential

Gram stain

Culture

and

Crystal analysis.

Synovial White Blood Cell Count

A very high synovial WBC count strongly supports:

Septic arthritis.

Historical descriptions emphasized counts above:

100,000 cells/µL

with greater than:

90% polymorphonuclear leukocytes.

However, infection may occur with substantially lower counts.

Therefore:

No single synovial WBC threshold reliably rules septic arthritis in or out.

Neutrophil Predominance

A high percentage of:

Polymorphonuclear leukocytes

supports the diagnosis, particularly in the appropriate clinical setting.

Synovial Glucose and Protein

In bacterial infection, synovial fluid may demonstrate:

Reduced glucose

and

Elevated protein.

These findings are nonspecific and are not relied upon as primary diagnostic criteria.

Gram Stain

The aspirate should be sent for:

Gram stain.

A positive result may guide immediate antibiotic selection, but sensitivity is limited.

A negative Gram stain does not exclude:

Septic arthritis.

Culture

Synovial fluid culture is essential to identify:

The causative organism

and its:

Antimicrobial sensitivities.

Crystal Analysis

The aspirate should also be examined for:

Monosodium urate crystals

and

Calcium pyrophosphate crystals

to evaluate for:

Gout

or

Pseudogout.

The presence of crystals does not completely exclude:

Concomitant infection.

Blood Cultures

Patients with suspected septic arthritis should have:

Blood cultures

obtained before antibiotic administration whenever possible.

Blood cultures may identify the organism even when:

Synovial fluid cultures are negative.

Imaging

Plain Radiographs

Early radiographs may show:

Joint effusion

Soft-tissue swelling

or pre-existing:

Degenerative changes.

They may otherwise be normal.

Chronic Infection

Long-standing infection may eventually produce:

Joint-space narrowing

Subchondral erosion

Bone destruction

and secondary:

Degenerative change.

MRI

MRI is particularly useful when the diagnosis is:

Uncertain

or when there is concern for:

Adjacent osteomyelitis

Soft-tissue abscess

Popliteal cyst infection

or extensive:

Synovitis.

Baker Cyst

A large or infected:

Popliteal or Baker cyst

may coexist with septic arthritis.

If infected, it may serve as a persistent reservoir and potentially:

Reinoculate the knee joint.

Pathological Findings

Untreated infection causes progressive:

Synovial inflammation

followed by:

Articular cartilage destruction.

Cartilage Damage

Bacterial toxins and inflammatory enzymes can damage cartilage within:

A few days.

This is the major reason prompt:

Drainage

and

Antibiotic treatment

are required.

Bone Destruction

The severity of bone involvement depends on:

Organism virulence

and

Duration of untreated infection.

Long-Standing Infection

Advanced disease may progress to:

Fibrous ankylosis

Bony ankylosis

Osteomyelitis

or

Septicemia.

Differential Diagnosis

Important alternative diagnoses include:

Acute osteomyelitis

Periarticular cellulitis

Prepatellar bursitis

Gout

Pseudogout

Acute rheumatoid arthritis

Juvenile idiopathic arthritis

Hemarthrosis from hemophilia

Lyme arthritis

Prepatellar Bursitis

Prepatellar bursitis usually causes swelling:

Anterior to the patella

without the profound pain on passive short-arc knee motion typical of:

Intra-articular septic arthritis.

Gout and Pseudogout

Crystal arthritis can closely mimic infection with:

Acute pain

Effusion

Warmth

and

Erythema.

Definitive distinction often requires:

Joint aspiration.

Lyme Arthritis

Lyme arthritis may produce a:

Large knee effusion

but often causes less pain with:

Short-arc passive motion

than typical acute bacterial septic arthritis.

Treatment

General Principles

Treatment requires:

Early diagnosis

Prompt antibiotics

and

Adequate joint drainage.

The knee usually requires:

Arthroscopic or open irrigation and débridement.

Early Nonoperative Management

In carefully selected cases diagnosed very early, an initial trial of:

Intravenous antibiotics

with

Serial joint aspiration

may be considered.

This requires:

Very close monitoring.

Failure of Aspiration

Persistent or recurrent:

Effusion

Purulence

Fever

or clinical deterioration should prompt:

Surgical drainage.

Urgent Irrigation and Débridement

The infected knee should generally be:

Irrigated and débrided urgently

to reduce bacterial burden and protect:

Articular cartilage.

Repeat Débridement

Some infections require:

Multiple surgical washouts

before infection is controlled.

Popliteal Cyst Drainage

An infected or communicating:

Popliteal cyst

may need drainage if it serves as a persistent source of:

Reinfection.

Immobilization

A:

Knee immobilizer

may be used temporarily during the acute painful phase.

Duration of Immobilization

Prolonged immobilization should be avoided.

Once infection and pain improve, the patient should begin:

Gentle active and passive range-of-motion exercises.

Physical Therapy

After control of the acute infection, rehabilitation should focus on:

Restoring knee motion

Quadriceps strength

Gait

and overall:

Lower-extremity function.

Medication

Empiric Antibiotics

Antibiotic treatment should begin promptly after:

Synovial fluid

and

Blood cultures

are obtained whenever clinically feasible.

Initial Coverage

Empiric therapy should provide coverage for:

Gram-positive organisms

particularly:

Staphylococcus aureus.

Coverage for:

MRSA

should be considered according to patient risk factors and local resistance patterns.

Additional Coverage

Broader antibiotic coverage may be required in patients with:

Immunocompromise

Intravenous drug use

Recent surgery

Gram-negative risk factors

or other specific exposures.

Definitive Antibiotics

Once Gram stain, culture, and susceptibility results are available, antibiotics should be narrowed to:

Organism-specific therapy.

Surgery

Arthroscopic Irrigation and Débridement

Arthroscopy is commonly used to:

Drain the joint

Break up loculations

Remove purulent material

and perform:

Synovectomy when necessary.

Open Irrigation and Débridement

An open approach may be used when:

Arthroscopic drainage is inadequate

Infection is advanced

or extensive tissue destruction requires:

Direct exposure.

Irrigation

The joint is washed with large volumes of:

Sterile saline

until gross contamination and purulence are removed.

Loculations

All accessible:

Loculations

should be disrupted to permit:

Complete drainage.

Drains

A temporary:

Intra-articular drain

may occasionally be used until:

Inflammation and drainage decrease.

Follow-Up

Patients require close monitoring after treatment.

Important parameters include:

Pain

Fever

Knee swelling

Range of motion

CRP

ESR

and clinical evidence of:

Recurrent effusion.

Prognosis

When diagnosed and treated:

Early

the prognosis is generally:

Good.

Delayed Treatment

Outcomes deteriorate substantially when diagnosis is delayed.

Historical reports suggested that delays beyond approximately:

2–4 days

increase the risk of:

Permanent cartilage injury

and poor joint function.

Complications

Articular Cartilage Destruction

Persistent infection can cause irreversible:

Cartilage erosion

leading to:

Post-infectious osteoarthritis.

Fibrous Ankylosis

Severe inflammation may cause scar formation and eventual:

Fibrous ankylosis.

Bony Ankylosis

Advanced destructive infection may rarely lead to:

Bony fusion of the knee.

Osteomyelitis

Infection may extend into the:

Femur

Tibia

or

Patella

causing:

Osteomyelitis.

Septicemia

Bacterial dissemination can result in:

Sepsis

or

Septicemia.

Degenerative Joint Disease

Even after eradication of infection, damaged cartilage may result in:

Chronic pain

Stiffness

and progressive:

Degenerative joint disease.

Recurrent Infection

Incomplete drainage or inadequate antimicrobial treatment may lead to:

Persistent or recurrent septic arthritis.

Patient Monitoring

Patients should be monitored closely for:

Clinical improvement

Resolution of fever

Reduction in joint swelling

Improved motion

and declining:

Inflammatory markers.

Reaccumulating effusion or failure to improve should prompt consideration of:

Repeat aspiration

Repeat imaging

or

Repeat surgical débridement.

Key Principle

Septic knee is a serious infection of the knee joint, most commonly caused by Staphylococcus aureus, that can rapidly destroy articular cartilage if treatment is delayed.

The key diagnostic test is:

Joint aspiration with synovial fluid cell count, differential, Gram stain, culture, and crystal analysis.

Treatment generally requires:

Prompt empiric antibiotics after cultures and urgent drainage of the knee, most commonly by arthroscopic irrigation and débridement.

Early treatment usually results in a good outcome, whereas delay may lead to:

Cartilage destruction, osteomyelitis, ankylosis, septicemia, and secondary degenerative joint disease.

Orthopaedic Surgery - Septic Hip

Basics

Septic arthritis of the hip is:

An infection of the hip joint

most commonly caused by:

Bacteria.

It can occur in:

Infants

Children

Adults

and

Older adults.

Although traditionally more common in the pediatric population, septic hip is increasingly encountered in:

Older

and

Immunocompromised patients.

Clinical Importance

Septic hip is an:

Orthopaedic emergency

because infection can rapidly damage the:

Femoral head

Acetabulum

and

Articular cartilage.

Early diagnosis and drainage are essential for:

Joint preservation.

Common Predisposing Factors

Important risk factors include:

Previous hip surgery

Hip arthroplasty

Intravenous drug use

Alcohol misuse

Corticosteroid therapy

and other causes of:

Immunosuppression.

Epidemiology

In children, the hip is one of the:

Most common sites of septic arthritis.

In adults, septic arthritis more commonly affects the:

Knee

than the hip.

Prosthetic Hip Infection

Historical estimates have reported infection after total hip arthroplasty in approximately:

2% of cases

although rates vary according to:

Patient factors

Procedure type

and

Definition of infection.

Risk Factors

Risk factors may be divided into:

Local

and

Systemic factors.

Local Risk Factors

These include:

Previous hip surgery

Previous total hip arthroplasty

Intra-articular hip injection

Femoral or iliac osteomyelitis

Osteoarthritis

Avascular necrosis

Previous trauma

Systemic Risk Factors

These include:

Bacteremia

Immunosuppression

Intravenous drug use

Hemophilia

Seronegative inflammatory arthritis

Sickle cell disease

Pathophysiology

In adults, infection may develop through:

Direct inoculation

particularly after:

Surgery

or another invasive procedure.

Hematogenous Spread

In children, infection more commonly reaches the hip through:

Hematogenous spread.

Bacteria circulating in the bloodstream may lodge in the highly vascular:

Synovium

and subsequently invade the joint.

Possible Primary Sources

Sources of bacteremia may include:

Urinary tract infection

Pulmonary infection

Skin and soft-tissue infection

or another systemic infectious focus.

Direct Extension

Infection may also spread directly from adjacent:

Femoral osteomyelitis

Iliac osteomyelitis

Psoas infection

or surrounding soft tissues.

Etiology

Bacteria may enter the hip joint through:

Bloodstream seeding

Direct inoculation

or extension through abnormal or inflamed:

Synovium

or

Joint capsule.

Staphylococcus aureus

The most common organism in both:

Children

and

Adults

is:

Staphylococcus aureus.

Other Causative Organisms

Additional organisms include:

Streptococcus species

Neisseria gonorrhoeae

Pseudomonas species

Escherichia coli

Salmonella species

Klebsiella species

Mycobacterium tuberculosis

Brucella species

Kingella kingae

Kingella kingae

Kingella kingae is particularly important in:

Young children.

It may be difficult to isolate on routine culture and sometimes requires:

Molecular testing.

Sickle Cell Disease

In patients with sickle cell disease, organisms such as:

Salmonella

should be considered, particularly when associated:

Osteomyelitis

is present.

Associated Conditions

Conditions frequently associated with septic hip include:

Osteomyelitis

Hemophilia

Sickle cell disease

Intravenous drug use

Immunosuppression

Diagnosis

Diagnosis requires a combination of:

Clinical suspicion

Laboratory testing

Imaging

and, most importantly,

Hip aspiration.

Signs and Symptoms

Typical symptoms include:

Hip pain

Groin pain

Medial thigh pain

Fever

and

Reduced hip motion.

Groin and Thigh Pain

Pain is commonly localized to the:

Groin

or

Inner thigh.

Referred Knee Pain

Some patients, especially children, may present primarily with:

Ipsilateral knee pain.

Therefore, unexplained knee pain should prompt examination of the:

Hip.

Systemic Symptoms

Patients may have:

Fever

and occasionally:

Chills

or other evidence of:

Systemic infection.

However, fever may be absent in:

Immunocompromised

or

Older patients.

Gait

Patients may demonstrate:

Antalgic gait

or may be completely:

Unable to bear weight.

Guarding

The hip is frequently:

Guarded

with marked resistance to passive motion.

Physical Examination

Position of Comfort

Patients often hold the hip in:

Flexion

and

External rotation.

This position increases intracapsular volume and may reduce painful:

Joint pressure.

Tenderness

Tenderness may be present around the:

Hip

Groin

or proximal:

Thigh.

Range of Motion

Passive hip motion is:

Restricted

and typically causes significant:

Pain.

Pain with even small arcs of passive movement is an important finding.

Weight Bearing

Inability or refusal to:

Stand

Walk

or

Bear weight

is particularly concerning in children.

Laboratory Tests

Laboratory abnormalities are variable and may be less pronounced in:

Immunocompromised patients.

ESR

The:

Erythrocyte sedimentation rate

is commonly elevated.

It is useful as a supportive test and for:

Monitoring treatment response.

C-Reactive Protein

CRP is often elevated and is particularly useful because it responds relatively quickly to:

Active infection

and subsequent:

Clinical improvement.

Peripheral White Blood Cell Count

The peripheral WBC count may be:

Elevated

or

Normal.

A normal value does not exclude:

Septic hip.

Neutrophils

When leukocytosis is present, there is often an increased percentage of:

Polymorphonuclear leukocytes.

Blood Cultures

Blood cultures should be obtained before antibiotics whenever possible.

They may identify the causative organism when the:

Joint culture is negative.

Hip Aspiration

Hip aspiration is the:

Most important diagnostic test.

Synovial fluid should be sent for:

Cell count

Differential

Gram stain

Culture

and susceptibility testing.

Synovial White Blood Cell Count

Septic hip often produces a markedly elevated synovial WBC count.

Historical descriptions include values between approximately:

100,000 and 250,000 cells/µL.

However, lower counts may still occur, and the diagnosis should not depend on:

A single threshold.

Gram Stain

Gram stain may occasionally demonstrate the infecting organism, but its sensitivity is:

Limited.

A negative Gram stain does not exclude:

Septic arthritis.

Culture-Negative Infection

A substantial proportion of septic hips may remain:

Culture negative

even when the clinical diagnosis is convincing.

Possible reasons include:

Prior antibiotic exposure

Low organism burden

or

Fastidious organisms.

Pediatric Considerations

Diagnosis in:

Neonates

and

Children

can be particularly difficult because symptoms may be nonspecific.

Clinical Prediction Features

Features that increase concern for septic arthritis in a child include:

Fever above approximately 38.5°C

Inability to bear weight

Elevated ESR

and

Elevated CRP.

These findings are often incorporated into:

Kocher-type clinical prediction criteria.

They help estimate probability but do not replace:

Hip aspiration.

Imaging

Plain Radiographs

Early radiographs may remain:

Normal

for up to approximately:

2 weeks.

Early Radiographic Findings

Possible early changes include:

Increased joint-space width

or widening of the:

Teardrop interval

caused by joint effusion.

Late Radiographic Findings

Delayed or advanced infection may cause:

Bone erosion

Femoral head destruction

Acetabular destruction

Subluxation

and other destructive changes.

Ultrasound

Ultrasound is especially useful in:

Neonates

and

Children.

It can identify:

Hip joint effusion

and guide:

Diagnostic aspiration.

MRI

MRI is highly useful for evaluating:

Joint effusion

Synovitis

Soft-tissue infection

Osteomyelitis

Pelvic fracture

Psoas or retroperitoneal collections.

Nuclear Imaging

Nuclear medicine studies may occasionally be used when:

The diagnosis remains uncertain

or multiple sites of infection are suspected.

Diagnostic Procedure

Image-guided:

Hip aspiration

is the key diagnostic procedure.

Because the hip is a deep joint, aspiration is generally performed using:

Ultrasound

or

Fluoroscopic guidance.

Pathological Findings

Untreated infection can cause rapid destruction of:

The femoral head

and

Acetabulum.

Late Pathology

Advanced cases may develop:

Septicemia

Hip subluxation

Dislocation

Deformity

Ankylosis

and permanent:

Cartilage destruction.

Differential Diagnosis

Important alternatives include:

Crystal arthropathy

Inflammatory arthritis

Rheumatoid arthritis

Hemarthrosis from hemophilia

Transient synovitis

Lyme arthritis

Psoas abscess

Sacroiliac joint infection

Femoral or iliac osteomyelitis

Pyomyositis

Leukemia

Lymphoma

Transient Synovitis

Transient synovitis is an important pediatric differential diagnosis.

It generally causes less:

Systemic illness

and lower inflammatory markers than:

Septic arthritis.

Osteomyelitis

Osteomyelitis of the:

Proximal femur

or

Pelvis

may mimic septic hip or coexist with it.

MRI is especially useful for distinguishing or identifying:

Combined infection.

Psoas Abscess

A psoas abscess may produce:

Hip pain

Flexion posture

and

Pain with extension.

Cross-sectional imaging is required when this diagnosis is suspected.

Treatment

Initial Stabilization

Early diagnosis is critical to:

Preserve the hip joint.

Cultures Before Antibiotics

When the patient is clinically stable, obtain:

Synovial fluid

and

Blood cultures

before beginning antibiotic treatment.

In a septic or unstable patient, treatment should not be dangerously delayed.

Empiric Antibiotics

After cultures are obtained, begin:

Empiric intravenous antibiotics

directed toward likely organisms based on:

Age

Risk factors

Gram stain

and

Local antibiotic resistance patterns.

Definitive Antibiotics

Once cultures and sensitivities are available, therapy should be changed to:

Organism-specific antibiotics.

Surgery

The traditional cornerstone of treatment is:

Surgical drainage and débridement.

Open Irrigation and Débridement

Open surgery allows:

Complete drainage

Removal of purulent material

Synovectomy when necessary

and inspection of the:

Hip joint.

Arthroscopic Débridement

Hip arthroscopy may be used in selected patients to:

Irrigate

and

Débride the joint.

Its appropriateness depends on:

Age

Disease severity

Surgeon expertise

and

Associated pathology.

Serial Aspiration

If a patient is too medically unstable to tolerate surgery, repeated:

Image-guided aspirations

may sometimes be used as temporary or alternative drainage.

Close monitoring is essential.

Prosthetic Joint Infection

Management of an infected total hip arthroplasty differs from treatment of a native-joint septic hip.

Suppressive Antibiotics

Long-term suppressive antibiotics alone are generally reserved for patients who:

Cannot tolerate surgery

or in whom definitive reconstruction is not possible.

Débridement With Implant Retention

Débridement, antibiotics, and implant retention may be considered when:

The infection is acute

Implants are stable

and symptoms have been present for only a:

Short period.

One-Stage Revision

A one-stage revision removes the infected components, performs thorough:

Débridement

and places a new prosthesis during the:

Same operation.

This may be appropriate in carefully selected patients.

Two-Stage Revision

Two-stage revision historically has been considered one of the most reliable strategies for chronic:

Periprosthetic hip infection.

The first stage involves:

Removal of components

Débridement

and often placement of an:

Antibiotic spacer.

Definitive reconstruction is performed later after infection control.

Late Sequelae in Children

Children with residual deformity may eventually require procedures such as:

Pelvic osteotomy

Hip reconstruction

Hip fusion

or, in severe destructive cases,

Resection procedures.

Late Sequelae in Adults

Adults with severe joint destruction may require:

Resection arthroplasty

or staged:

Total hip replacement.

Referral

A patient with a painful hip and concern for infection should be referred:

Urgently to an orthopaedic surgeon.

Delay in diagnosis substantially increases the risk of:

Permanent joint damage.

Prognosis

If treatment begins:

Early

the prognosis is generally:

Good.

Delayed Diagnosis

Outcomes become significantly worse when diagnosis and treatment are:

Delayed.

Persistent infection may rapidly destroy the:

Femoral head

and

Acetabulum.

MRSA

Infections caused by:

Methicillin-resistant Staphylococcus aureus

may be associated with:

More severe disease

and more complicated treatment than infections caused by susceptible organisms.

Complications

Osteomyelitis

Infection may spread into the:

Proximal femur

or

Pelvis

producing:

Osteomyelitis.

Septicemia

Bacteria may enter the bloodstream and cause:

Systemic sepsis.

Subluxation and Dislocation

Accumulation of pus and destruction of supporting structures may cause:

Hip subluxation

or

Dislocation.

This is particularly concerning in:

Children.

Avascular Necrosis

Severe infection may compromise blood supply to the:

Femoral head

and lead to:

Osteonecrosis.

Physeal Injury

In children, infection may damage the:

Proximal femoral physis

and result in:

Growth disturbance

Angular deformity

or

Limb-length discrepancy.

Degenerative Joint Disease

Cartilage destruction may ultimately cause:

Secondary osteoarthritis

and chronic:

Pain and stiffness.

Deformity

Delayed or inadequately treated childhood infection can result in permanent:

Hip deformity

and loss of:

Joint congruity.

Ankylosis

Advanced destruction and healing may result in:

Severe stiffness

or

Ankylosis.

Patient Monitoring

Patients should be monitored closely for:

Fever

Pain

Range of motion

Weight-bearing ability

CRP

ESR

and other signs of response to treatment.

Failure to Improve

Persistent:

Pain

Fever

Joint effusion

or worsening inflammatory markers should raise concern for:

Inadequate drainage

Resistant infection

Associated osteomyelitis

or another undrained:

Abscess.

Repeat:

Aspiration

MRI

or

Surgical débridement

may be necessary.

Key Principle

Septic hip is a serious infection of the hip joint that can occur at any age and can rapidly destroy the femoral head and acetabulum.

The most common organism is:

Staphylococcus aureus, while hematogenous spread is particularly important in children and direct inoculation after surgery is a major mechanism in adults.

The most important diagnostic test is:

Image-guided hip aspiration for synovial fluid analysis and culture.

Treatment requires:

Prompt antibiotics after appropriate cultures and urgent joint drainage, usually by surgical irrigation and débridement.

Delayed treatment may result in:

Osteomyelitis, sepsis, subluxation or dislocation, osteonecrosis, growth disturbance, deformity, and secondary degenerative joint disease.

Orthopaedic Surgery - Septic Arthritis of the Foot

Basics

Septic arthritis of the foot is:

A bacterial or fungal infection involving one or more joints of the foot.

It may develop through:

Hematogenous spread

Direct inoculation

or

Contiguous extension from an adjacent soft-tissue or bone infection.

Because infection can rapidly damage articular cartilage, prompt diagnosis and treatment are essential.

Prevention

Preventive measures include:

Appropriate footwear

Avoidance of walking barefoot in high-risk environments

Prevention of puncture wounds

and careful treatment of:

Diabetic

or

Neuropathic foot ulcers.

Good wound care is particularly important in patients with impaired:

Sensation

Vascular supply

or

Immune function.

Risk Factors

Important risk factors include:

Previous joint trauma

Pre-existing arthritis

Puncture wounds of the foot

Inflammatory arthropathy

Diabetes mellitus

Immunocompromise

Skin disease

Peripheral vascular disease

Intravenous drug use

Previous Joint Disease

A previously damaged or arthritic joint may be more susceptible to:

Bacterial seeding

and subsequent septic arthritis.

Diabetes and Neuropathy

Patients with diabetes or peripheral neuropathy are at increased risk because of:

Unrecognized skin injury

Ulceration

Impaired host defense

and possible direct spread of infection into:

Bone and joint.

Peripheral Vascular Disease

Poor perfusion reduces:

Tissue oxygenation

and

Immune-cell delivery

which can impair the ability to contain infection.

Pathophysiology

Joint damage results from a combination of:

Direct bacterial injury

and the host:

Inflammatory response.

Bacterial Factors

Bacteria may release:

Enzymes

and

Toxins

that directly damage:

Articular cartilage.

Neutrophil-Mediated Injury

Activated neutrophils release:

Proteases

Cytokines

and other inflammatory mediators that further damage:

Cartilage

and

Synovium.

Ischemic Injury

Accumulation of purulent material within the joint can impair:

Oxygen diffusion

and increase intra-articular pressure.

This may contribute to:

Ischemic cartilage damage.

Etiology

Septic arthritis of the foot may arise through several mechanisms.

Hematogenous Spread

Bacteremia can seed the:

Synovial membrane

and establish infection within the joint.

Direct Inoculation

A:

Puncture wound

or penetrating trauma may directly introduce organisms into a joint.

Iatrogenic Infection

Joint infection may occasionally follow:

Arthrocentesis

Arthroscopy

or other invasive procedures.

Contiguous Spread

In patients with:

Diabetes

Peripheral neuropathy

or

Peripheral vascular disease

infection may spread directly from:

Ulcerated skin

or

Adjacent osteomyelitis

into the joint.

Associated Conditions

The most important associated condition is:

Osteomyelitis.

Because the bones and joints of the foot are anatomically close together, septic arthritis and osteomyelitis may occur:

Simultaneously.

Diagnosis

Diagnosis is based on:

Clinical examination

Joint aspiration

Laboratory analysis

and

Imaging.

Signs and Symptoms

Typical findings include:

Warmth

Swelling

Joint pain

Reduced range of motion

and difficulty with:

Weight bearing.

Systemic Symptoms

Some patients may also develop:

Fever

Chills

Sweats

or other signs of systemic infection.

However, systemic symptoms may be absent, particularly in:

Older

Diabetic

or

Immunocompromised patients.

Physical Examination

The goal of examination is to identify the:

Specific joint involved

and determine whether infection extends into:

Adjacent soft tissues

or

Bone.

Palpation

Carefully palpate for:

Localized tenderness

Swelling

Warmth

and

Fluctuance.

Skin Examination

Inspect for:

Erythema

Ulceration

Puncture wound

Drainage

or other portals of entry.

Range of Motion

Septic arthritis typically causes:

Marked pain with passive joint motion

and substantial:

Restriction of range of motion.

Weight Bearing

Patients frequently have difficulty:

Standing

or

Walking

on the affected extremity.

Vascular and Neurologic Examination

Particularly in patients with diabetes, assess:

Peripheral pulses

Capillary refill

Protective sensation

and evidence of:

Peripheral neuropathy.

Laboratory Tests

Joint Aspiration

Aspiration of the suspected joint is a key diagnostic step.

Synovial fluid should be sent for:

Cell count

Differential

Gram stain

Culture

and

Crystal analysis.

Crystal Analysis

Testing for:

Urate crystals

is useful because:

Gout

commonly affects foot joints and can closely mimic infection.

The presence of crystals does not absolutely exclude:

Concurrent septic arthritis.

Synovial Culture

Synovial fluid culture is essential for identifying:

The causative organism

and determining:

Antibiotic susceptibility.

Blood Cultures

Blood cultures should also be obtained, especially when:

Fever

Sepsis

or suspected:

Hematogenous spread

is present.

Imaging

Plain Radiographs

Radiographs may demonstrate:

Soft-tissue swelling

Joint-space abnormalities

or signs of:

Adjacent osteomyelitis.

Early infection may still have:

Normal radiographs.

CT

CT may demonstrate:

Joint effusion

Cortical destruction

and bony changes associated with:

Osteomyelitis.

It is particularly useful for defining:

Bone anatomy.

MRI

MRI is highly useful because it can evaluate:

Joint effusion

Synovitis

Soft-tissue abscess

Bone marrow edema

and

Adjacent osteomyelitis.

It is often the preferred advanced study when the extent of infection is uncertain.

Pathological Findings

Foot-joint infections may develop through:

Direct inoculation

Contiguous spread

or

Hematogenous seeding.

Most Common Organism

The most common causative organism is:

Staphylococcus aureus.

Gram-Positive Organisms

In adults, most septic arthritis of the foot is caused by:

Gram-positive bacteria.

Haemophilus influenzae

Historically:

Haemophilus influenzae

was an important pathogen in children younger than approximately:

6 years.

Its incidence has declined substantially following widespread:

Hib vaccination.

Pseudomonas

Pseudomonas species should be considered after:

Puncture wounds through footwear

particularly injuries involving the:

Sole of an athletic shoe.

Diabetic Foot Infection

Patients with:

Diabetes

Foot ulcers

or

Peripheral vascular disease

are more likely to develop:

Polymicrobial infection

including:

Gram-negative organisms

and

Anaerobes.

Differential Diagnosis

Important alternatives include:

Fracture

Soft-tissue abscess

Osteomyelitis

Gout

Tumor

Reactive arthritis

Charcot neuroarthropathy

Gout

Gout may produce:

Acute redness

Severe pain

Swelling

and

Joint effusion

particularly in the:

First metatarsophalangeal joint.

Joint aspiration is often needed to distinguish:

Crystal arthritis

from

Infection.

Charcot Arthropathy

Charcot neuroarthropathy may cause:

Warmth

Swelling

and

Bony destruction

in patients with neuropathy.

The degree of pain may be surprisingly low because of:

Sensory loss.

Osteomyelitis

Adjacent osteomyelitis should always be considered when infection involves:

Small joints of the foot

especially in the presence of:

Ulceration

or

Puncture wounds.

Treatment

General Principles

Acute septic arthritis requires:

Prompt antibiotics

Adequate drainage

and protection of the affected joint.

Initial Antibiotics

Empiric intravenous antibiotics should be selected according to:

Likely organism

Patient risk factors

Local resistance patterns

and the suspected:

Route of infection.

Whenever possible, cultures should be obtained before antibiotics are started.

Repeated Aspiration

Selected acute infections may be managed with:

Parenteral antibiotics

and

Repeated joint aspiration

provided the joint can be adequately drained and the patient is:

Improving clinically.

Failure of Aspiration

Surgical drainage should be considered when:

Purulence persists

Effusions continue to recur

Clinical improvement is inadequate

or infection is:

Chronic.

Historical Timing

Older recommendations suggested surgical drainage when effusions continued beyond approximately:

5–6 days

or when repeated aspiration failed to achieve adequate control.

Current management is individualized and may proceed to surgery earlier when infection is severe.

Immobilization

During the acute painful phase, the joint may be:

Splinted

to reduce motion and discomfort.

Weight Bearing

Patients are generally kept:

Non-weight-bearing

or protected from weight bearing during the acute infection, particularly when there is associated:

Bone involvement

or substantial joint destruction.

Duration of Immobilization

Prolonged immobilization should be avoided once infection is controlled because of the risk of:

Stiffness

and

Contracture.

Physical Therapy

After the acute infection begins to resolve, physical therapy may help restore:

Range of motion

Strength

Balance

and

Gait mechanics.

Ankle Motion

Early controlled ankle motion is particularly useful for preventing:

Equinus contracture

and chronic:

Stiffness.

Medication

Initial antibiotic therapy should provide empiric coverage based on:

Clinical setting

and

Expected organisms.

Definitive Antibiotics

Once culture results are available, treatment should be narrowed to:

Organism-specific antibiotics.

The total treatment duration depends on:

Organism

Joint involved

Presence of osteomyelitis

and

Clinical response.

Puncture-Wound Infection

When infection follows a plantar puncture through footwear, empiric treatment may need to consider:

Pseudomonas

in addition to usual:

Gram-positive organisms.

Diabetic or Polymicrobial Infection

Patients with diabetic foot ulcers or severe soft-tissue infection may require broader initial coverage for:

Gram-positive bacteria

Gram-negative bacteria

and

Anaerobes.

Surgery

Acute infection that responds rapidly to aspiration and antibiotics may not require surgery.

However, surgical treatment becomes important when adequate drainage cannot otherwise be achieved.

Indications for Surgical Débridement

Surgical drainage or débridement is particularly indicated in patients with:

Sepsis

Immunocompromise

Diabetes or significant systemic disease

Chronic infection

Delayed presentation

Adjacent soft-tissue abscess

Necrotizing infection

Gram-negative infection with tissue destruction

Failure of repeated aspiration

Arthroscopic Débridement

Uncomplicated septic arthritis of the:

Ankle

may be treated arthroscopically.

Arthroscopy permits:

Irrigation

Synovectomy

and

Removal of purulent material.

Open Arthrotomy

Many smaller joints of the foot are more commonly treated through:

Open arthrotomy and débridement.

This allows direct access to:

Infected tissue

and adjacent:

Bone.

Osteomyelitis Débridement

Any associated:

Necrotic bone

or

Osteomyelitis

should be débrided when necessary.

Soft-Tissue Débridement

Necrotic or infected soft tissue should also be removed to reduce:

Bacterial burden

and improve:

Wound healing.

Follow-Up

Patients require:

Close clinical monitoring

until the infection and joint effusion resolve.

Repeat Aspiration

If the effusion:

Reaccumulates

the joint may require:

Repeat aspiration

or progression to:

Surgical drainage.

Prognosis

Most infections can be eradicated with:

Early recognition

Appropriate antibiotics

and adequate:

Drainage or débridement.

Prognostic Factors

Outcome is influenced by:

Duration of infection

Host immune status

Presence of diabetes

Peripheral vascular disease

Osteomyelitis

and extent of:

Cartilage destruction.

Complications

Joint Destruction

Delayed treatment may result in:

Articular cartilage destruction

with permanent loss of:

Joint function.

Osteomyelitis

Infection may extend into adjacent bone and produce:

Chronic osteomyelitis.

Chronic Infection

Persistent infection can lead to:

Sinus formation

Chronic drainage

and recurrent:

Soft-tissue infection.

Joint Stiffness

Inflammation and prolonged immobilization may result in:

Contracture

and

Reduced range of motion.

Resection

Advanced infection may require:

Resection of infected bone or joint surfaces.

Amputation

Severe progressive infection, particularly in patients with:

Diabetes

Ischemia

or extensive:

Necrotic tissue

may ultimately require:

Partial foot or limb amputation.

Patient Monitoring

Follow-up should assess:

Pain

Swelling

Joint effusion

Range of motion

Wound condition

Systemic signs of infection

and response to:

Antibiotic therapy.

Laboratory Monitoring

Serial measurements of:

CRP

and other inflammatory markers may assist in determining:

Treatment response.

Imaging Follow-Up

Repeat radiographs or MRI may be required when there is concern for:

Ongoing osteomyelitis

Abscess

Joint destruction

or treatment failure.

Key Principle

Septic arthritis of the foot is a serious joint infection that commonly arises from hematogenous spread, puncture wounds, or extension from diabetic or neuropathic ulcers.

The diagnosis depends on:

Careful localization of the affected joint, joint aspiration with synovial fluid analysis and culture, and imaging to assess for associated osteomyelitis or abscess.

Treatment requires:

Prompt antibiotics, adequate joint drainage, temporary protection from weight bearing, and surgical débridement when aspiration is insufficient or infection is advanced.

Patients with:

Diabetes, neuropathy, vascular disease, puncture wounds, or adjacent osteomyelitis

require especially close monitoring because progressive infection may ultimately lead to:

Joint destruction, bone resection, or amputation.

Orthopaedic Surgery - Septic Arthritis

Basics

Septic arthritis is:

Infection of a synovial joint

caused most commonly by:

Bacteria.

It represents an:

Orthopaedic emergency

because persistent infection can rapidly destroy:

Articular cartilage

and, in children, may damage the:

Epiphysis

and

Growth plate.

Pediatric Anatomy

In young infants, vascular channels may cross the:

Physis

from the metaphysis toward the epiphysis.

These transphyseal vessels persist during approximately the first:

12–18 months of life.

As a result, infection can spread from:

Metaphyseal osteomyelitis

through the:

Epiphysis

and into the:

Adjacent joint.

Growth-Plate Injury

Infection involving the immature joint can cause irreversible damage to the:

Physis

or

Cartilaginous epiphysis.

Potential consequences include:

Growth disturbance

Angular deformity

and

Limb-length discrepancy.

Polyarticular Septic Arthritis

Although most cases involve:

A single joint

multiple joints may be involved.

Historical series have reported polyarticular involvement in approximately:

5% of patients.

Prevention

Preventive measures include prompt recognition and treatment of:

Bacteremia

Skin and soft-tissue infection

Systemic infection

and sexually transmitted infections such as:

Gonorrhea.

The most important preventive principle is:

Early diagnosis and treatment

before permanent cartilage or growth-plate damage occurs.

Epidemiology

Septic arthritis can occur in:

Any joint

and at:

Any age.

Sex

There is no strong sex predominance in most forms of:

Nongonococcal monoarticular septic arthritis.

Gonococcal arthritis has historically been reported more commonly in:

Women

than men.

Incidence

The incidence varies substantially according to:

Age

Immune status

Comorbidities

and presence of:

Prosthetic joints.

Neonatal septic arthritis is uncommon but particularly serious.

Risk Factors

Important risk factors include:

Neonatal age

Prematurity

Concurrent bacteremia

Inflammatory arthritis

Prosthetic joint

Diabetes mellitus

HIV or other immunocompromised states

Hemophilia

Sickle cell disease

Intravenous drug use

Recent joint surgery or injection

Skin infection

Neonatal Risk

Neonates may have several potential portals of infection, including:

Umbilical infection

Intravenous lines

Skin lesions

or systemic bacteremia.

Rheumatologic Disease

Patients with inflammatory arthritis are at increased risk because of:

Underlying joint disease

and frequently:

Immunosuppressive medication.

Prosthetic Joints

Joint prostheses provide a surface on which organisms can form:

Biofilm

making infection difficult to eradicate without:

Surgical intervention.

Sickle Cell Disease

Patients with sickle cell disease have increased susceptibility to:

Musculoskeletal infection.

Historically, both:

Staphylococcus aureus

and

Salmonella species

have been emphasized, particularly in associated osteomyelitis.

Intravenous Drug Use

Intravenous drug use increases the risk of bacteremia with organisms including:

Staphylococcus aureus

and selected:

Gram-negative organisms.

Etiology

The causative organism varies with:

Age

Host factors

and

Exposure history.

Staphylococcus aureus

Across many age groups, the most important pathogen is:

Staphylococcus aureus.

It is particularly important in:

Infants

Children

and

Adults.

Neonates

Potential organisms include:

Staphylococcus aureus

Group B Streptococcus

Gram-negative enteric bacilli

and, less commonly,

Candida species.

Young Children

In young children, important organisms include:

Staphylococcus aureus

Streptococcal species

and

Kingella kingae.

Haemophilus influenzae

Historically:

Haemophilus influenzae type b

was an important cause of septic arthritis in children younger than approximately:

2 years.

Its incidence declined dramatically following widespread:

Hib vaccination.

Kingella kingae

Kingella kingae is particularly important in:

Young children, often between approximately 6 months and 4 years.

It is:

Fastidious

and may be difficult to isolate using routine culture.

Diagnosis may require:

PCR or other molecular testing.

Adolescents and Young Adults

In sexually active adolescents and young adults, consider:

Neisseria gonorrhoeae.

Staphylococcus aureus remains an important alternative.

Other Organisms

Other causes include:

Streptococci

Gram-negative bacilli

Pseudomonas

and less common organisms depending on:

Immune status

and

Exposure.

Culture-Negative Infection

A causative organism may not be recovered in a substantial proportion of cases.

Culture negativity may result from:

Previous antibiotic therapy

Low organism burden

Fastidious organisms

or limitations of conventional culture methods.

Lyme Arthritis

Lyme disease can produce:

Infectious inflammatory arthritis, particularly of the knee.

However, it generally follows a different clinical pattern from:

Acute pyogenic septic arthritis

and is managed differently.

Associated Conditions

Septic arthritis may occur together with:

Osteomyelitis.

This association is particularly important in:

Infants

and when infection involves the:

Hip

or other joints adjacent to metaphyseal bone.

Diagnosis

Diagnosis depends on:

Clinical suspicion

Joint aspiration

Synovial fluid analysis

Culture

and supporting laboratory and imaging studies.

Signs and Symptoms

Children commonly present with:

Fever

Irritability

Pain

Refusal to move the affected extremity

and reduced:

Appetite or activity.

Subtle Presentation

Not every child appears severely ill.

Some may present only with:

Fever of unknown origin

or relatively subtle findings localized to:

One extremity.

Neonatal Presentation

Neonates may show very nonspecific findings such as:

Poor feeding

Failure to gain weight

Reduced spontaneous limb movement

or irritability.

Only a minority may initially demonstrate obvious:

Sepsis.

Earliest Physical Finding

One of the earliest and most sensitive findings is:

Pain with joint movement.

This may precede visible:

Swelling

or

Erythema.

Later Findings

As infection progresses, patients may develop:

Swelling

Warmth

Muscle spasm

Restricted range of motion

and

Joint effusion.

Erythema

Overlying erythema may be:

Absent

because the inflammatory process is located deep within the:

Joint capsule.

Its absence does not exclude infection.

Physical Examination

The affected joint should be examined for:

Tenderness

Pain with passive motion

Swelling

Warmth

Effusion

and loss of:

Active and passive movement.

Position of Comfort

Patients often hold the joint in a position that maximizes:

Capsular volume

and reduces:

Intra-articular pressure.

Hip

A child with septic arthritis of the hip may hold the hip in:

Flexion

Abduction

and

External rotation.

Weight bearing is often:

Painful or impossible.

Systemic Examination

Assess for potential sources of bacteremia, including:

Skin infection

Respiratory infection

Urinary infection

and signs of:

Systemic sepsis.

Laboratory Tests

Synovial Fluid

Joint aspiration is the key diagnostic procedure.

Fluid should be sent for:

Cell count

Differential

Gram stain

Aerobic and anaerobic culture

and additional testing when indicated.

Synovial White Blood Cell Count

A synovial white-cell count above approximately:

50,000 cells/µL

with a predominance of:

Neutrophils

strongly supports septic arthritis in the appropriate clinical setting.

However, no single cutoff absolutely confirms or excludes:

Infection.

Neutrophil Predominance

Purulent septic arthritis often demonstrates:

More than 90% polymorphonuclear leukocytes.

Gram Stain

Gram stain has limited sensitivity.

It may be positive in only approximately:

30–40% of cases.

A negative Gram stain therefore does:

Not exclude septic arthritis.

Synovial Culture

Culture of aspirated joint fluid remains essential for identifying:

The causative organism

and its:

Antibiotic sensitivities.

Blood Cultures

Blood cultures should be obtained:

Before antibiotics whenever this can be done without delaying treatment.

They may identify the organism even when:

Synovial cultures are negative.

ESR

The:

Erythrocyte sedimentation rate

may be elevated.

It is useful mainly as a supportive test and for:

Following response to treatment.

Limitations of ESR

ESR may be less reliable in:

Neonates

Patients with sickle cell disease

and patients receiving:

Corticosteroids.

C-Reactive Protein

CRP is especially useful because it:

Rises relatively early

and falls relatively quickly with successful treatment.

Serial CRP measurement can therefore help assess:

Treatment response.

Peripheral White Blood Cell Count

A high systemic WBC count with a:

Left shift

may support infection but is:

Nonspecific.

A normal peripheral WBC count does not exclude:

Septic arthritis.

Crystals

Synovial fluid should be examined for:

Urate

or

Calcium pyrophosphate crystals

when crystal arthritis is possible.

The presence of crystals does not completely exclude:

Concomitant infection.

Imaging

Plain Radiographs

Early radiographs may be normal or show only:

Soft-tissue swelling

Joint-space widening from effusion

or distention of the:

Joint capsule.

Hip in Infants

In neonatal hip infection, radiographs may occasionally demonstrate:

Lateral displacement of the proximal femur

relative to the:

Acetabulum

because of a large effusion.

Ultrasound

Ultrasound is particularly useful for detecting an:

Effusion

in deep joints such as the:

Hip.

It can also guide:

Joint aspiration.

MRI

MRI is valuable when:

The diagnosis is uncertain

Adjacent osteomyelitis is suspected

or evaluation of deep structures is required.

It can identify infection within the:

Joint

Bone

Muscle

and surrounding:

Soft tissues.

Pathological Findings

The joint typically contains:

Purulent synovial fluid

with a marked:

Neutrophilic inflammatory response.

Synovial Changes

The synovium becomes:

Hyperemic

Inflamed

and

Thickened.

Cartilage Destruction

If infection remains untreated, bacterial toxins, inflammatory cells, and enzymes begin to damage:

Articular cartilage

within a relatively short period.

This can ultimately lead to:

Permanent joint destruction.

Differential Diagnosis

Important alternatives include:

Osteomyelitis

Transient synovitis

Inflammatory arthritis

Crystal arthritis

Rheumatologic disease

Pyomyositis

Trauma

Malignancy

Transient Synovitis of the Hip

Transient synovitis usually occurs in a child who is:

Less systemically ill

and typically has lower:

Temperature

Inflammatory markers

and

Peripheral WBC count.

Kocher-Type Clinical Features

Features favoring septic arthritis of the hip include:

Inability to bear weight

Fever

Elevated inflammatory markers

and

Elevated peripheral WBC count.

No clinical prediction rule should replace:

Joint aspiration when septic arthritis remains a significant concern.

Treatment

Orthopaedic Emergency

Suspected bacterial septic arthritis should be treated as an:

Emergency.

Hospitalization is often appropriate, particularly for:

Children

Systemically ill adults

and infections of:

Large joints.

Core Treatment Principles

Management consists of:

Prompt joint aspiration

Blood cultures

Immediate bactericidal antibiotics

Adequate drainage

and subsequent:

Restoration of motion.

Timing of Antibiotics

When the patient is clinically stable, obtain:

Synovial fluid

and

Blood cultures

before starting antibiotics.

Antibiotic treatment should then begin:

Promptly.

In a septic or unstable patient, antibiotic treatment should not be dangerously delayed for diagnostic procedures.

Empiric Antibiotics

Initial therapy is generally:

Intravenous

and should provide coverage for the most likely organisms according to:

Age

Risk factors

Local resistance patterns

and

Gram-stain findings.

Staphylococcal Coverage

Because:

Staphylococcus aureus

is a common cause, empiric therapy usually includes strong:

Antistaphylococcal coverage.

Local prevalence of:

MRSA

must be considered.

Definitive Antibiotics

Once the organism and antimicrobial sensitivities are known, therapy should be narrowed to:

Targeted antibiotic treatment.

Duration of Therapy

Treatment duration depends on:

Organism

Joint involved

Presence of osteomyelitis

Clinical response

and host factors.

Historical regimens commonly used approximately:

3–6 weeks of total antibiotic treatment.

Many uncomplicated cases can now be treated with shorter individualized regimens under specialist guidance.

Intravenous-to-Oral Transition

Transition to oral treatment may be appropriate when:

Clinical improvement is clear

The organism is identified or adequately covered

An effective oral agent is available

The patient can reliably take oral medication

and inflammatory markers are:

Improving.

Serial Aspiration

In selected superficial or easily accessible joints, early infection may sometimes be managed with:

Repeated aspiration

plus antibiotics.

The patient must be monitored closely for:

Rapid clinical improvement.

Hip Aspiration

Aspiration of the hip should usually be performed with:

Ultrasound

or

Fluoroscopic guidance.

Surgical Drainage

Surgical drainage is particularly important for:

Hip infection

Large-joint infection

Loculated purulent effusion

Failure to improve with aspiration and antibiotics

or extensive:

Synovitis and debris.

Arthroscopic Irrigation and Débridement

Arthroscopic treatment is commonly used for joints such as the:

Knee

Shoulder

Elbow

and

Ankle.

It allows:

Irrigation

Synovectomy

and removal of:

Purulent material and debris.

Open Irrigation and Débridement

Open drainage remains appropriate when:

Arthroscopic access is inadequate

Infection is advanced

The hip is involved in selected patients

or complete clearance cannot otherwise be achieved.

Gonococcal Arthritis

Disseminated gonococcal arthritis may often respond to:

Appropriate antibiotic therapy

and aspiration without formal surgical drainage, provided there is no persistent:

Purulent joint infection.

Immobilization

Initially, the joint may be splinted in a:

Comfortable position

to control pain.

Duration of Immobilization

Prolonged immobilization should be avoided.

Once:

Pain

Swelling

and

Tenderness

begin to improve, gradual:

Range-of-motion exercises

should begin.

Physical Therapy

Rehabilitation is important to prevent:

Stiffness

Contracture

and

Muscle wasting.

Early Exercises

Adults may begin with:

Isometric strengthening

followed by progressive:

Active range of motion.

Continuous Passive Motion

Continuous passive motion has historically been proposed to:

Reduce adhesions

and improve:

Cartilage nutrition.

Its role depends on the involved joint and current rehabilitation protocol.

Surgery

The goals of operative treatment are to:

Drain purulent fluid

Reduce bacterial burden

Remove inflammatory debris

and decrease enzymes that can destroy:

Articular cartilage.

Open Drainage

Open irrigation and débridement allows direct removal of:

Necrotic synovium

Pus

and

Debris.

Drainage may be maintained when clinically necessary.

Follow-Up

Patients require close follow-up until:

Clinical signs resolve

Inflammatory markers improve

and useful joint function returns.

Prognosis

With:

Prompt diagnosis

Adequate drainage

and

Appropriate antibiotics

the prognosis is generally:

Good.

Poor Prognostic Factors

Outcomes are less favorable in:

Premature infants

Immunocompromised patients

Patients with delayed diagnosis

and those with:

Systemic sepsis.

Delay in Treatment

A delay of several days can substantially increase the risk of:

Permanent cartilage destruction

and other complications.

Historical series identified delays beyond approximately:

5 days

as particularly concerning.

Complications

Cartilage Destruction

Ongoing infection may destroy:

Articular cartilage

leading to:

Pain

Restricted movement

Secondary osteoarthritis

or

Ankylosis.

Pathologic Hip Dislocation

In children with delayed treatment of septic arthritis of the hip, a large effusion and structural damage may result in:

Pathologic dislocation.

Growth-Plate Damage

In children, injury to the:

Physis

and

Cartilaginous epiphysis

can cause:

Growth arrest

Angular deformity

and

Limb-length discrepancy.

Femoral Head Necrosis

Severe hip infection may compromise the blood supply to the:

Femoral head

causing:

Osteonecrosis

and subsequent:

Growth disturbance

or

Degenerative joint disease.

Joint Stiffness

Inflammation, prolonged immobilization, and cartilage injury may lead to:

Loss of motion

or permanent:

Contracture.

Hematogenous Prosthetic Joint Seeding

Patients with prosthetic joints elsewhere in the body may develop:

Hematogenous prosthetic joint infection

during episodes of:

Bacteremia.

Patient Monitoring

Patients should initially be monitored in the hospital until:

Hemodynamic and clinical stability are achieved

Appropriate antibiotic therapy is established

and there is clear evidence of:

Treatment response.

Signs of Improvement

Expected findings include:

Resolution of fever

Reduced swelling

Reduced tenderness

Improved range of motion

and declining:

CRP and other inflammatory markers.

Lack of Improvement

Persistent:

Fever

Pain

Effusion

or worsening inflammatory markers may indicate:

Inadequate drainage

Resistant organism

Associated osteomyelitis

or an incorrect diagnosis.

Repeat:

Aspiration

Imaging

or

Surgical débridement

may be necessary.

Key Principle

Septic arthritis is a joint infection that can rapidly destroy articular cartilage and therefore must be considered an orthopaedic emergency.

The diagnosis depends on:

Clinical suspicion and urgent joint aspiration, with synovial fluid sent for cell count, Gram stain, and culture.

Treatment requires:

Prompt antibiotics after appropriate cultures, effective drainage of the infected joint, and early rehabilitation once inflammation begins to improve.

In children, particularly infants, delayed treatment can result in:

Growth-plate injury, deformity, limb-length discrepancy, hip dislocation, osteonecrosis, and permanent loss of joint function.

Orthopaedic Surgery - Scoliosis

Basics

Scoliosis is a:

Three-dimensional deformity of the spine

characterized by lateral curvature together with:

Vertebral rotation

and changes in the normal sagittal alignment.

Although often described on an:

AP or PA spinal radiograph

the deformity is not purely lateral.

Definition

Radiographic scoliosis is conventionally defined as a spinal curve measuring:

More than 10° by the Cobb method.

Both the:

Thoracic

and

Lumbar spine

may be involved.

Classification

Scoliosis can be classified according to:

Etiology

Location of the curve

and, in idiopathic cases,

Age at onset.

Classification by Etiology

Major categories include:

Idiopathic

Congenital

Neuromuscular

Connective-tissue associated

Degenerative

Classification by Curve Location

The curve is named according to the level of its:

Apex.

Common categories are:

Thoracic

Thoracolumbar

Lumbar

Idiopathic Scoliosis by Age

Idiopathic scoliosis may be subdivided into:

Infantile scoliosis – younger than 3 years

Juvenile scoliosis – 3–10 years

Adolescent scoliosis – approximately 11 years to skeletal maturity

Epidemiology

The most common form is:

Idiopathic scoliosis.

Scoliosis may appear at:

Any age.

Adolescent idiopathic scoliosis is most commonly recognized between approximately:

10 and 13 years of age.

Prevalence

Curves greater than:

10°

occur in approximately:

2–3% of the population.

Sex

Small idiopathic curves occur at approximately similar rates in:

Boys and girls.

However, girls are approximately:

3–4 times more likely

to develop significant:

Curve progression.

Bracing and Surgery Prevalence

Historical estimates suggest that approximately:

0.3%

develop curves large enough to require:

Brace treatment.

Approximately:

1 in 1,000

may ultimately require:

Surgical treatment.

Risk Factors for Progression

Factors associated with increased risk of curve progression include:

Female sex

Positive family history

Skeletal immaturity

Premenarchal status

Larger curve magnitude at presentation

Neuromuscular Risk Factors

Progressive deformity is also common in patients with:

Severe spinal cord injury before adolescence

Paralysis

Cerebral palsy with extensive involvement

and other severe neuromuscular disorders.

Genetics

Idiopathic scoliosis has a significant:

Familial component.

Older descriptions suggested an:

Autosomal-dominant pattern with incomplete penetrance and variable expression

in some families.

Modern understanding supports a more:

Complex polygenic and multifactorial inheritance.

Etiology

Idiopathic Scoliosis

By definition, there is no single identifiable cause.

Proposed mechanisms have included abnormalities involving:

Connective tissue

Neuromuscular control

Growth regulation

Neurohormonal signaling

and

Genetic susceptibility.

Congenital Scoliosis

Congenital scoliosis results from abnormal vertebral development.

Examples include:

Hemivertebra

and

Failure of segmentation or congenital vertebral fusion.

Neuromuscular Scoliosis

Neuromuscular scoliosis may occur with:

Cerebral palsy

Traumatic paralysis

Spina bifida

Poliomyelitis

Friedreich ataxia

Charcot–Marie–Tooth disease

Duchenne muscular dystrophy

and many other neurologic or muscular disorders affecting:

Trunk control.

Connective-Tissue Associated Scoliosis

Scoliosis may occur with disorders such as:

Marfan syndrome

Ehlers–Danlos syndrome

Neurofibromatosis

Down syndrome

and other systemic connective-tissue conditions.

Associated Conditions

Almost any disorder that affects:

Neurologic control of the trunk

or

Connective-tissue integrity

can predispose to scoliosis.

Diagnosis

Diagnosis is based on:

Standing physical examination

and

Standing spinal radiographs.

Signs and Symptoms

Symptoms vary with:

Curve location

Curve magnitude

Age

and

Underlying cause.

Thoracic Curves

Thoracic curves cause rotation of the:

Rib cage.

On the convex side, the ribs rotate posteriorly, producing a:

Rib prominence or rib hump.

The scapula on the same side may also appear:

More prominent.

Thoracolumbar and Lumbar Curves

These curves may produce:

Waist asymmetry

and an apparent:

High hip.

One side of the pelvis or flank may appear more prominent.

Pain

Many adolescents have:

Little or no pain.

Some develop mild back discomfort, but substantial pain is not typical of uncomplicated adolescent idiopathic scoliosis and should prompt evaluation for:

Other causes.

Adult Symptoms

In adulthood, patients may develop:

Mechanical back pain

Degenerative changes

and occasionally:

Nerve-root symptoms.

Growth History

In girls, menstrual history is useful because:

Menarchal status

helps estimate remaining skeletal growth and therefore risk of:

Curve progression.

Physical Examination

The examination should be performed with the patient:

Standing.

Inspection

Assess for asymmetry of:

Shoulders

Scapulae

Rib cage

Waist

Pelvis

Leg Length

Measure both lower extremities because:

Leg-length discrepancy

can produce an apparent functional scoliosis or pelvic tilt.

Adams Forward-Bend Test

The:

Adams forward-bend test

is one of the most useful screening maneuvers.

The patient bends forward with:

Knees straight

and the examiner looks along the spine for asymmetry of the:

Ribs

or

Lumbar paraspinal region.

Rib Prominence

Scoliosis causes rotational deformity that becomes more obvious during:

Forward flexion.

A thoracic curve may produce a:

Rib hump

on the convex side.

Scoliometer

A:

Scoliometer

can quantify trunk rotation.

A trunk rotation measurement around:

5–7° or greater

commonly prompts consideration of:

Radiographic evaluation

depending on age, clinical context, and screening protocol.

False-Positive Forward-Bend Test

Some patients have:

Trunk asymmetry

without a radiographic scoliosis greater than 10°.

Therefore, an abnormal forward-bend test alone does not establish:

Structural scoliosis.

Sagittal Alignment

Observe for abnormal:

Kyphosis

and

Lordosis.

Skin Examination

Inspect the skin over the spine for:

Dimples

Hairy patches

Vascular markings

or other cutaneous stigmata that may suggest:

Underlying spinal dysraphism or congenital abnormality.

Ligamentous Laxity

Generalized:

Joint hypermobility

should be assessed when connective-tissue disease is suspected.

Neurocutaneous Findings

Look for:

Café-au-lait macules

Neurofibromas

or other findings suggestive of:

Neurofibromatosis.

Neurologic Examination

A careful neurologic examination is essential.

Assess:

Gait

Strength

Sensation

Reflexes

and

Abdominal reflexes.

Functional Neurologic Assessment

Useful screening observations include:

Heel walking

Toe walking

Single-leg hopping

and overall:

Gait symmetry.

Abdominal Reflexes

Asymmetric or absent abdominal reflexes may raise concern for:

Underlying spinal cord pathology

such as:

Syringomyelia.

Physical Maturity

Growth potential should be assessed using:

Secondary sexual characteristics

Menarchal status

Height changes

and radiographic indicators of:

Skeletal maturity.

Serial Height

Height should be measured over time because rapid growth is associated with a higher risk of:

Curve progression.

Imaging

Standing Spinal Radiographs

The standard study is a:

Standing posteroanterior full-length spinal radiograph.

This allows measurement of:

Curve magnitude

Coronal balance

and

Skeletal maturity.

Cobb Angle

The:

Cobb angle

is measured between the most tilted vertebrae at the:

Upper and lower ends of the curve.

A curve greater than:

10°

meets the radiographic definition of scoliosis.

Lateral Radiograph

A standing lateral view is useful when evaluating:

Kyphosis

Lordosis

or other sagittal deformity.

Risser Stage

The iliac crest apophysis can be used to estimate:

Skeletal maturity.

The:

Risser stage

ranges from:

0 – little or no iliac apophyseal ossification

to

5 – complete ossification and fusion.

Greater Risser stage generally indicates:

Less remaining spinal growth.

Triradiate Cartilage

An open:

Triradiate cartilage

of the pelvis indicates substantial:

Skeletal immaturity

and that the major growth period is not yet complete.

MRI

MRI is not routinely required for every patient with typical adolescent idiopathic scoliosis.

It is indicated when there is concern for:

Spinal cord abnormality

Neurologic findings

Atypical curve pattern

Significant unexplained pain

or other suspicious features.

Early-Onset Scoliosis

MRI is commonly obtained for clinically significant:

Infantile

and

Juvenile scoliosis

because the likelihood of underlying:

Neural-axis abnormalities

is higher.

Pathological Findings

In structural scoliosis, the vertebrae undergo:

Rotation

toward the convexity of the curve.

Vertebral Remodeling

As the child grows while the spine remains curved, individual vertebrae may become:

Asymmetrically shaped

or

Wedged.

The deformity therefore becomes increasingly:

Three-dimensional.

Differential Diagnosis

Important alternatives include:

Isolated rib asymmetry

Kyphosis

Leg-length discrepancy

Sprengel deformity

Clavicular deformity or previous fracture

Postural scoliosis

Functional Scoliosis

Leg-length inequality can produce an apparent:

Pelvic tilt and compensatory spinal curve.

Unlike a true structural scoliosis, this may improve when the:

Pelvis is leveled.

Kyphosis

Kyphosis is primarily a deformity in the:

Sagittal plane.

It can occasionally be mistaken clinically for scoliosis when shoulder or trunk asymmetry is prominent.

Treatment

General Principles

The spine in uncomplicated scoliosis is:

Not mechanically unstable.

Patients should generally remain:

Active.

Bone Health

Adequate:

Calcium

and

Vitamin D

should be maintained through diet or supplementation when indicated.

Exercise

Exercise may improve:

Strength

Conditioning

Posture

and

Back discomfort.

It does not reliably correct the structural Cobb angle by itself.

Observation

Growing children with relatively small curves, generally:

Less than approximately 20–25°

are usually managed with:

Observation and serial examination.

Skeletally Mature Patients

A patient with a small stable curve who has reached:

Skeletal maturity

may no longer require routine pediatric deformity follow-up.

Bracing

Bracing is generally considered for:

Moderate idiopathic curves

in children who still have significant:

Growth remaining.

Typical Bracing Range

Brace treatment is commonly used for curves around:

25–40°

in skeletally immature patients.

Goal of Bracing

The goal is not necessarily to permanently straighten the spine.

The primary aim is to:

Reduce the risk of curve progression

and decrease the likelihood of:

Surgery.

Brace Effectiveness

Full-time brace treatment has been shown to reduce progression risk in appropriately selected:

Growing adolescents with idiopathic scoliosis.

Effectiveness depends heavily on:

Brace wear time

and

Remaining growth.

Large Curves

Curves greater than approximately:

40–45°

should be evaluated by an:

Orthopaedic spine specialist.

Surgical Threshold

Surgery is commonly considered for progressive adolescent idiopathic curves around:

45–50° or greater

particularly when substantial growth remains or progression is documented.

Infantile Scoliosis

Selected children with progressive infantile scoliosis may benefit from:

Serial corrective casting.

Casting may be continued over:

Several months

and can occasionally substantially correct early flexible curves.

Physical Therapy

Physical therapy may help patients with:

Pain

Stiffness

Poor conditioning

or postural difficulty.

Exercise Program

Exercises may include:

Core strengthening

Spinal extensor strengthening

Flexibility work

Postural training

Aerobic conditioning.

Curve-Specific Exercises

Specialized scoliosis-specific exercise programs may help with:

Postural control

Trunk symmetry

and function in selected patients.

They are generally considered an adjunct rather than a replacement for:

Observation, bracing, or surgery when otherwise indicated.

Complementary Therapies

Yoga or similar flexibility and conditioning activities may help with:

Back discomfort

and general well-being.

They have not been shown to reliably correct a significant structural curve.

Surgery

The goal of surgery is to:

Correct deformity

Prevent further progression

and maintain overall:

Spinal balance.

Posterior Instrumentation and Fusion

A common operation uses:

Posterior spinal instrumentation

with rods, screws, and bone graft.

The curved portion of the spine is:

Corrected and fused.

Fusion Levels

Only the necessary portion of the spine is included in the fusion to preserve as much:

Spinal mobility

as safely possible.

Bone Graft

Bone graft is placed along the instrumented segment to promote:

Solid vertebral fusion.

Neurologic Risk

Major neurologic injury is:

Uncommon

with modern techniques and intraoperative neurologic monitoring.

Historical estimates placed the risk at:

Less than approximately 1%.

Follow-Up

Children with scoliosis should generally be followed until:

Skeletal maturity

or until the curve is clearly stable.

Growing Children

During periods of rapid growth, patients are commonly reviewed every:

4–6 months.

Adult Follow-Up

Adults with established curves may be followed every:

1–5 years

depending on:

Symptoms

Curve magnitude

and

Evidence of progression.

Congenital Scoliosis

Patients with congenital scoliosis require assessment for associated abnormalities involving:

Spinal cord

Kidneys

Heart

and other organ systems depending on the vertebral anomaly.

Prognosis

Prognosis depends on:

Curve magnitude

Curve type

Remaining growth

Underlying diagnosis.

Adult Progression

Many untreated curves greater than approximately:

40–50° at skeletal maturity

continue to progress slowly during adulthood.

Pulmonary Function

Major pulmonary compromise is uncommon in typical moderate adolescent idiopathic scoliosis.

It becomes a concern particularly with:

Very severe thoracic curves

especially those exceeding approximately:

70–100°.

Neuromuscular and Congenital Curves

Severe congenital or neuromuscular scoliosis may produce:

Restrictive pulmonary disease

and, in extreme cases:

Cor pulmonale.

Back Pain

Curves greater than approximately:

40°

may be associated with an increased frequency of:

Back pain in adulthood.

However, many adults with scoliosis remain highly functional.

Complications

Potential complications of severe untreated scoliosis include:

Progressive deformity

Chronic back pain

Degenerative changes

Radiculopathy

Reduced pulmonary function in severe thoracic curves

Surgical Complications

Potential complications include:

Neurologic injury

Infection

Pseudarthrosis or failure of fusion

Implant problems

Loss of correction

Patient Monitoring

Growing patients should be monitored for:

Curve magnitude

Curve progression

Skeletal maturity

Height

Neurologic status

Brace compliance when applicable

Radiographic Monitoring

Serial standing radiographs are used to document:

Cobb angle progression

while minimizing unnecessary radiation exposure.

Key Principle

Scoliosis is a three-dimensional spinal deformity defined radiographically by a Cobb angle greater than 10°.

The most common form is:

Adolescent idiopathic scoliosis.

Management is determined primarily by:

Curve magnitude, skeletal maturity, and risk of progression.

Small curves are generally:

Observed, moderate progressive curves in growing children may require:

Bracing, and curves approaching or exceeding approximately:

45–50°

may require consideration of:

Surgical correction and spinal fusion.

Orthopaedic Surgery - Sciatica

⸻

Basics

Sciatica refers to:

Pain radiating from the lower back or buttock into the lower extremity along the distribution of a lumbosacral nerve root.

The sciatic nerve is formed mainly from the:

L4–S3 nerve roots, although higher lumbar radiculopathies involving L2–L4 can produce related anterior-thigh symptoms.

⸻

Typical Pain Distribution

Sciatic or radicular pain may be experienced in several regions.

⸻

Low Back

Pain may begin in the:

Midline or paraspinal lumbosacral region

and then radiate toward the hip or leg.

⸻

Buttock

Patients may describe:

Deep, cramping, aching pain

within the buttock.

⸻

Posterior or Lateral Thigh

Compression of the:

L5

or

S1

nerve roots commonly causes pain in the:

Posterior or lateral thigh.

Some patients experience symptoms in both regions.

⸻

Anterior Thigh

Higher lumbar radiculopathy involving:

L2

L3

or

L4

may cause pain in the:

Anterior or medial thigh.

⸻

Epidemiology

Sciatica is relatively common.

Historical estimates suggest that approximately:

2% of the general population

may be affected at a given time, with a lifetime occurrence approaching:

40%.

⸻

Etiology

The most common cause is:

Lumbar intervertebral disc herniation

with compression and inflammation of a:

Lumbosacral nerve root.

The most frequently affected disc levels are:

L4–L5

and

L5–S1.

⸻

Pathophysiology

The:

Nucleus pulposus

may protrude or extrude through a weakened or torn:

Annulus fibrosus.

The resulting disc material can compress or chemically irritate an adjacent:

Nerve root.

Both:

Mechanical compression

and

Inflammatory mediators

contribute to radicular pain.

⸻

Diagnosis

Diagnosis is based primarily on:

History

Neurologic examination

Nerve-root tension signs

and selective imaging.

⸻

Signs and Symptoms

Most patients have some history of:

Low-back pain

before the onset of leg symptoms.

A precipitating event may occur, such as:

Bending

Lifting

Straining

or sudden twisting.

Symptoms may begin:

Gradually

or

Abruptly.

⸻

Leg Pain

Leg pain is often:

More disabling than the back pain.

The distribution generally follows the affected nerve root.

⸻

Root-Specific Pain Patterns

L1

Pain may localize to the:

Groin.

⸻

L2

Symptoms may occur in the:

Medial or anterior thigh.

⸻

L3

Pain typically affects the:

Anterior thigh

and may extend toward the:

Medial knee.

⸻

L4

Pain may involve the:

Anterior thigh

Medial knee

and

Medial shin.

⸻

L5

Pain commonly travels through the:

Lateral thigh

Lateral calf

and

Dorsum of the foot.

⸻

S1

Symptoms commonly involve the:

Posterior thigh

Posterior calf

and

Lateral aspect of the foot.

⸻

Pain Below the Knee

In classic lower lumbar radiculopathy, pain frequently extends:

Below the knee.

This can help distinguish nerve-root pain from some forms of nonspecific referred back pain.

⸻

Foot Symptoms

Paresthesia is a common distal symptom.

⸻

L5

Tingling or numbness commonly affects the: