Orthopaedic Surgery - Patellar Fracture

Basics

A patellar fracture is a fracture involving the patella, or kneecap.

Because the patella forms part of the knee extensor mechanism, fracture displacement may disrupt continuity between the:

Quadriceps tendon

Patella

and

Patellar tendon.

Loss of extensor mechanism continuity can result in inability to actively extend the knee.

Classification

Patellar fractures are commonly classified according to fracture pattern.

Typical patterns include:

Vertical

Transverse

Stellate or comminuted

Superior or inferior pole

The degree of displacement, articular incongruity, and integrity of the extensor mechanism are also clinically important.

Pediatric Sleeve Fracture

In children, the characteristic injury is the:

Patellar sleeve fracture.

In this injury, a sleeve of:

Cartilage and periosteum

is avulsed from the developing patella, often together with the:

Patellar tendon.

Because much of the avulsed tissue is not ossified, the fracture may be difficult to identify on plain radiographs.

A clue is:

Patella alta

without an obvious large bony fragment.

For this reason, pediatric sleeve fractures are easily missed.

Epidemiology

Patellar fractures occur in:

Both males and females

and across a broad age range.

Incidence

Patellar fractures account for approximately:

1% of all skeletal fractures.

Risk Factors

The major risk factor is:

Direct blunt trauma to the anterior knee.

A classic mechanism is a:

Dashboard injury during a motor vehicle collision.

Etiology

Patellar fractures may result from:

Direct trauma

or

Indirect force through the extensor mechanism.

Direct Trauma

A direct blow to the patella, especially with the knee flexed, can produce:

Comminuted

Stellate

or other fracture patterns.

The exact pattern depends partly on:

Direction and magnitude of the impact

and

Degree of knee flexion.

Indirect Injury

A sudden, powerful eccentric contraction of the quadriceps against a flexed knee may generate enough force to produce a:

Transverse fracture

or

Patellar pole avulsion.

Fracture in Compromised Bone

Patellar fracture can also occur in structurally weakened bone, including after:

Total knee arthroplasty

Osteolysis

or

Patellar tendon graft harvest during ACL reconstruction.

Associated Injuries

Patellar fracture may occur with other significant injuries, including:

Femoral shaft fracture

Knee ligament injury

Other injuries caused by high-energy trauma

Diagnosis

Signs and Symptoms

Typical symptoms include:

Acute anterior knee pain

Swelling

Difficulty walking

and, in displaced injuries,

Inability to actively straighten the knee.

Physical Examination

The examination should determine both:

Fracture characteristics

and

Whether the extensor mechanism remains functional.

Swelling and Tenderness

Typical findings include:

Localized patellar tenderness

Anterior knee swelling

Hemarthrosis

Straight-Leg Raise

The ability to perform a:

Straight-leg raise

is an important test of extensor mechanism continuity.

Inability to perform the test raises concern for:

Displaced patellar fracture

Quadriceps tendon rupture

or

Patellar tendon rupture.

Palpable Defect

A gap may occasionally be:

Visible or palpable

across the patella or extensor mechanism.

Extensor Mechanism

The clinician should assess whether the patient can:

Actively extend the knee against gravity.

An intact retinaculum may sometimes preserve active extension despite a patellar fracture, so imaging remains important.

Imaging

Plain Radiographs

Standard imaging includes:

AP

and

Lateral radiographs.

Axial or Tangential Views

Axial or sunrise views can be particularly useful for identifying:

Vertical fractures

Marginal fractures

Articular incongruity

These views should be obtained only when clinically safe and tolerable.

CT

CT is not routinely required for a straightforward isolated patellar fracture.

It can be useful when there is:

Complex comminution

Uncertain fracture morphology

Need for detailed surgical planning.

MRI

MRI is rarely necessary for an isolated fracture but may help evaluate:

Cartilage injury

Retinacular injury

Associated ligamentous injury

Occult pediatric sleeve injury

Pathological Findings

Common associated findings include:

Hemarthrosis

and, in displaced fractures,

Disruption of the extensor mechanism.

The articular surface may also be damaged depending on the fracture pattern.

Differential Diagnosis

Important alternatives include:

Quadriceps tendon rupture

Patellar tendon rupture

Patellar dislocation

Posterior cruciate ligament injury

Osteochondral injury

Treatment

General Principles

Treatment is determined primarily by:

Fracture displacement

Articular congruity

Integrity of the extensor mechanism

Degree of comminution

Nondisplaced Fractures

Nondisplaced or minimally displaced fractures with an intact extensor mechanism can often be treated:

Nonoperatively.

Treatment usually involves:

A cast, brace, or splint with the knee in extension.

Follow-Up of Nonoperative Fractures

Close radiographic follow-up is important because a fracture that is initially well aligned may:

Displace during healing.

Weight Bearing

Many patients treated nonoperatively may:

Bear weight as tolerated with the knee locked in extension, depending on stability and pain.

Range of Motion

Range-of-motion exercises are introduced progressively once sufficient stability and healing are present.

Prolonged immobilization should be minimized when safe because it may contribute to:

Knee stiffness

Quadriceps atrophy

Displaced Fractures

Displaced fractures are generally treated with:

Open reduction and internal fixation, particularly when the extensor mechanism is disrupted.

Surgery allows:

Restoration of articular congruity

Restoration of extensor mechanism continuity

Earlier rehabilitation

Medication

Pain can be treated with:

Acetaminophen

and other appropriate analgesics.

NSAID use may be individualized based on fracture-healing considerations and patient comorbidities.

Short-term opioid medication may be used for:

Severe acute postoperative or fracture pain when necessary.

Surgery

Indications

Operative treatment is generally indicated for:

Significant fracture displacement

Articular step-off that cannot be accepted

Loss of extensor mechanism continuity

Open fracture

Displaced osteochondral or pole fragments

Tension-Band Fixation

Traditional fixation for a transverse patellar fracture uses:

Parallel Kirschner wires

with a:

Tension-band construct.

The construct converts tensile forces at the anterior patella into:

Compression across the fracture during knee flexion.

Cannulated Screw Fixation

Tension-band principles may also be applied using:

Parallel cannulated screws

with a tension-band construct.

This may provide stronger fixation and reduce some wire-related problems in selected fractures.

Stellate and Comminuted Fractures

Comminuted fractures may require:

Additional cerclage fixation

Multiple screws

Plates

or other modern fixation constructs.

The goal is to preserve as much viable patella and articular surface as possible.

Distal Pole Fractures

Small, nonreconstructible inferior-pole fragments were historically treated with:

Partial excision and patellar tendon repair.

Current treatment increasingly favors:

Fragment-preserving fixation when feasible

because preservation of patellar length and the extensor mechanism generally improves function.

Patellectomy

Partial or total patellectomy should be reserved for:

Rare, severely comminuted fractures that cannot be reconstructed.

Loss of patellar bone reduces:

Quadriceps mechanical efficiency

and may weaken knee extension.

Open Fractures

Open patellar fractures require:

Prompt irrigation and debridement

Appropriate antibiotics

and

Stable fixation when possible.

Every effort should be made to preserve:

Viable patellar bone

and

Extensor mechanism continuity.

Rehabilitation

Physical therapy is important after both operative and nonoperative treatment.

Goals include:

Restoring range of motion

Preventing stiffness

Rebuilding quadriceps strength

Normalizing gait

Returning to function

Prognosis

Nondisplaced fractures treated appropriately generally have a:

Good prognosis.

Displaced fractures also have favorable outcomes when:

Anatomic or near-anatomic alignment is restored

and

Stable fixation permits rehabilitation.

Elderly Patients

Older patients with displaced fractures and disruption of the extensor mechanism generally benefit from:

Operative restoration of continuity, provided they are suitable surgical candidates.

Complications

Nonunion and Malunion

Fracture healing may occasionally result in:

Nonunion

or

Malunion.

This may cause persistent:

Pain

Weakness

Extensor dysfunction

Refracture

Refracture can occur, particularly after:

Premature return to activity

or in the setting of compromised bone.

Symptomatic Hardware

Prominent wires or other fixation devices may cause:

Anterior knee pain

Soft-tissue irritation

and sometimes require:

Hardware removal.

This is one of the more common problems after traditional tension-band fixation.

Post-Traumatic Arthritis

Damage to the patellar articular surface may lead to:

Patellofemoral osteoarthritis.

Risk increases with:

Comminution

Residual articular incongruity

Cartilage loss

Extensor Mechanism Weakness

Quadriceps strength decreases as:

More of the patella is lost

Articular anatomy becomes more disrupted

or

Patellar height and mechanics become abnormal.

This is one reason preservation of the patella is preferred whenever possible.

Knee Stiffness

Prolonged immobilization or postoperative scarring may result in:

Loss of flexion

Arthrofibrosis

Early controlled motion helps reduce this risk when fixation is sufficiently stable.

Patient Monitoring

Serial clinical and radiographic follow-up should assess:

Fracture alignment

Healing

Extensor function

Range of motion

Hardware position

Radiographs are often repeated at approximately:

4–6-week intervals

until satisfactory union is demonstrated.

Key Principle

Patellar fracture management is determined primarily by fracture displacement and integrity of the extensor mechanism.

Stable, nondisplaced fractures with preserved active extension can often be treated with:

Immobilization in extension and progressive rehabilitation.

Displaced fractures or fractures that interrupt the extensor mechanism generally require:

Operative fixation with preservation of as much patellar bone and articular surface as possible.

Orthopaedic Surgery - Paronychia (Nail Infection)

⸻

Basics

Paronychia is an infection or inflammatory process involving the lateral nail fold, typically along the radial or ulnar margin of a fingernail.

It may occur acutely after disruption of the nail fold or chronically after repeated exposure to moisture and irritants.

⸻

Prevention

Preventive measures include:

Keeping nails clean and appropriately trimmed

Avoiding nail biting

Avoiding aggressive cuticle manipulation

Using gloves during wet work or exposure to irritants

Care should be taken during manicures to avoid injury to the nail fold.

⸻

Epidemiology

Paronychia can occur at any age.

Older studies suggest that it is more common in:

Women

with an approximate female-to-male ratio of:

3:1.

⸻

Risk Factors

Important risk factors include:

Nail biting

Hangnails

Manicures

Frequent water exposure

Diabetes mellitus

Chronic corticosteroid use

Chemotherapy

Other immunosuppressed states

⸻

Etiology

Acute paronychia usually develops after disruption of the protective barrier between the nail plate and surrounding skin.

Common precipitating events include:

Hangnail formation

Biting the nail edge

Picking at the cuticle

Manicure instrumentation

The most common bacterial pathogen is:

Staphylococcus aureus.

Other organisms may be involved depending on the clinical setting.

⸻

Associated Conditions

Several related infections may occur around the nail and fingertip.

⸻

Eponychia

Eponychia involves the:

Proximal nail fold and periungual tissues.

⸻

Felon

A felon is an infection of the:

Pulp space of the fingertip.

Because the pulp contains multiple fibrous septae, an abscess can generate substantial pressure and pain.

⸻

Subungual Abscess

A subungual abscess develops:

Beneath the nail plate.

Its management may require partial or complete nail removal if adequate drainage cannot otherwise be achieved.

⸻

Diagnosis

⸻

Signs and Symptoms

Typical findings include:

Redness

Swelling

Tenderness

Pain along one side of the nail fold

If an abscess is present, there may be:

Fluctuance

Purulent drainage

⸻

Physical Examination

Examine the entire fingertip and nail apparatus.

Assess for:

Lateral nail-fold swelling

Proximal nail-fold involvement

Subungual pus

Tenderness or fluctuance in the fingertip pulp

This helps distinguish uncomplicated paronychia from:

Felon

Eponychia

Subungual abscess

⸻

Laboratory Tests

Laboratory studies are usually unnecessary for uncomplicated localized paronychia.

They may be considered when:

The infection is severe

The infection is spreading

The patient is immunocompromised

Systemic infection is suspected

⸻

Cultures

Routine culture of drained pus is not always necessary in a simple uncomplicated case.

Culture becomes more useful when:

The infection is recurrent

Treatment has failed

There is extensive cellulitis

Unusual organisms are suspected

The patient is significantly immunocompromised

⸻

Imaging

Imaging is not routinely required initially.

Radiographs may be useful when the infection is:

Chronic

Aggressive

Associated with trauma

Unresponsive to appropriate treatment

or when there is concern for:

Foreign body or osteomyelitis.

⸻

Chronic Infection and Osteomyelitis

Longstanding infection may produce radiographic findings such as:

Cortical erosion

Bone resorption

or other changes compatible with:

Osteomyelitis.

⸻

Pathological Findings

Acute paronychia usually demonstrates:

Acute inflammatory changes

with neutrophilic infiltration and purulent material.

Staphylococcus aureus is a common causative organism.

⸻

Differential Diagnosis

Important alternatives include:

Eponychia

Felon

Subungual abscess

Herpetic whitlow

Mucous cyst

Psoriasis

Squamous cell carcinoma

Melanoma

Digital papillary adenocarcinoma

⸻

Herpetic Whitlow

Herpetic whitlow can mimic paronychia but typically presents with:

Grouped vesicles

Burning pain

Viral-type lesions

Incision and drainage should be avoided when herpetic whitlow is suspected.

⸻

Treatment

⸻

Early Acute Paronychia Without Abscess

When there is:

Erythema and tenderness without a drainable collection, treatment may include:

Warm soapy soaks

Local wound care

and, when clinically indicated,

Oral antibiotics.

⸻

Warm Soaks

Warm soaks may be performed several times daily to:

Promote drainage

Reduce swelling

Improve comfort

⸻

Abscess

Once a fluctuant abscess has formed, the key treatment is:

Incision and drainage.

⸻

Anesthesia

A:

Digital nerve block

with local anesthetic may be used before drainage.

⸻

Drainage

The abscess can be drained using:

A small scalpel incision

or

A needle or blunt instrument

depending on the size and location.

A blunt instrument may be used to gently elevate the nail fold and open the infected space.

⸻

Irrigation

After drainage, the wound may be irrigated with:

Saline solution

to remove residual purulent material and debris.

⸻

Septae and Loculations

Any loculated collection should be gently opened so that:

Pus can drain completely.

Forceful deep probing should be avoided.

⸻

Nail Removal

If pus extends beneath the nail, treatment may require:

Removal of the lateral portion of the nail plate

or, for a large subungual abscess,

Partial or complete nail removal.

⸻

Dressings

A nonadherent dressing may be placed beneath or around the nail fold after drainage.

If part of the nail plate is removed, the nail fold may be protected with:

Nonadherent sterile gauze or another spacer.

⸻

Antibiotics After Drainage

In a healthy patient with:

A localized uncomplicated abscess

that has been adequately drained and can be followed closely, routine antibiotics may not always be necessary.

Antibiotics are more appropriate when there is:

Cellulitis

Immunosuppression

Systemic symptoms

Incomplete drainage

High-risk comorbidity

⸻

Medication

When antibiotics are indicated, therapy should cover typical skin flora.

Common oral options include:

Cephalexin

Amoxicillin-clavulanate

Clindamycin

Trimethoprim-sulfamethoxazole

Choice depends on:

Allergy history

Local resistance patterns

Concern for MRSA

Clindamycin or trimethoprim-sulfamethoxazole may be considered when MRSA is a concern.

⸻

Chronic Paronychia

Chronic paronychia is generally defined as inflammation lasting:

More than 6 weeks.

It commonly occurs in individuals with repeated exposure to:

Water

Detergents

Chemical irritants

⸻

Pathophysiology of Chronic Paronychia

Chronic disease is often primarily an:

Irritant or inflammatory dermatitis

rather than a persistent bacterial infection.

Fungal organisms may colonize the affected nail fold, but colonization does not necessarily mean that antifungal therapy is required.

⸻

Chronic Paronychia Treatment

Management focuses on:

Avoiding irritants

Keeping the hands dry

Using protective gloves

Applying topical corticosteroids

Potential causative medications should be reviewed when appropriate.

⸻

Surgical Treatment for Chronic Disease

Severe or refractory chronic paronychia may require procedures such as:

Eponychial marsupialization

or

Temporary reflection of the proximal nail fold

to allow the chronically inflamed tissue to heal.

⸻

Surgery

Most acute paronychias do not require formal operating-room surgery.

They can usually be treated with:

Conservative care

or

Minor drainage under local anesthesia.

⸻

Nail Deformity

Nail removal may be considered when there is:

Marked nail deformity

Persistent subungual infection

Inadequate drainage beneath the nail

⸻

Follow-Up

The patient should generally be reassessed within approximately:

48 hours

after drainage or initiation of treatment.

⸻

Patient Monitoring

At follow-up, assess for:

Reduction in pain

Improvement in redness and swelling

Resolution of drainage

Return of normal finger use

Worsening symptoms should prompt reassessment for:

Persistent abscess

Felon

Deep infection

Osteomyelitis

⸻

Prognosis

The prognosis is generally:

Excellent with appropriate treatment.

Most acute infections resolve without long-term consequences.

⸻

Complications

⸻

Extension Into the Finger Pulp

Progression into the fingertip pulp may produce a:

Felon, which can require more extensive drainage.

⸻

Osteomyelitis

Untreated or prolonged infection may spread to the:

Distal phalanx

and produce osteomyelitis.

⸻

Nail Deformity

Infection or surgical injury involving the nail matrix may result in:

Permanent or temporary nail deformity.

⸻

Progressive Soft-Tissue Infection

Cellulitis may spread proximally if infection is not controlled.

This is more concerning in patients with:

Diabetes

Immunosuppression

or

Peripheral vascular disease.

⸻

Key Principle

Paronychia is a common infection or inflammatory disorder of the nail fold, usually following disruption of the protective nail barrier.

Management depends primarily on whether:

A drainable abscess is present.

Early cases without abscess may respond to:

Warm soaks and local care, whereas abscess formation requires:

Prompt drainage, with antibiotics reserved for selected patients with cellulitis, systemic disease, or other high-risk features.

Orthopaedic Surgery - Paget Disease

Basics

Paget disease of bone, also called osteitis deformans, is a chronic disorder of abnormally accelerated and disorganized bone remodeling.

It was first described by Sir James Paget in 1877.

The affected bone may become:

Enlarged

Deformed

Hypervascular

Mechanically weak despite increased density

Any bone may be affected.

Disease can be:

Monostotic, involving a single bone

or

Polyostotic, involving multiple bones.

The distribution is often asymmetric.

Phases of Disease

Paget disease progresses through characteristic remodeling phases.

Early Lytic Phase

The earliest phase is dominated by:

Excessive osteoclastic bone resorption.

Radiographs may show advancing areas of osteolysis.

Mixed Phase

During the mixed phase, there is simultaneous:

Accelerated bone resorption

and

Disorganized new bone formation.

This produces characteristic enlargement and architectural distortion.

Late Sclerotic Phase

Later disease becomes predominantly:

Osteoblastic and sclerotic.

The bone may appear dense but remains structurally abnormal.

Inactive Disease

Some older patients develop metabolically inactive disease with:

No progressive radiographic change

Few or no symptoms

Normal or near-normal biochemical markers

Epidemiology

Paget disease primarily affects:

Middle-aged and older adults.

It is rare before approximately:

40 years of age.

Prevalence rises substantially with increasing age.

Historical Prevalence

Older studies reported disease in approximately:

3–4% of adults older than 50 years

in populations where Paget disease was common.

Prevalence has historically been highest in:

People of European ancestry, particularly in the United Kingdom.

The disease is slightly more common in:

Men.

Geographic Distribution

Paget disease has traditionally been more common in:

Britain

Western Europe

Australia

New Zealand

and populations descended from these regions.

Its prevalence appears to have declined in several countries over recent decades.

Risk Factors

Important risk factors include:

Advancing age

Positive family history

A first-degree relative with Paget disease substantially increases risk.

Genetics

There is strong evidence of a genetic contribution.

First-degree relatives of affected patients have historically been reported to have a risk up to:

Several times greater than that of the general population.

Variants involving genes that regulate:

Osteoclast differentiation and signaling

have been identified in familial disease.

Etiology

The exact cause is not fully established.

Current understanding supports an important:

Genetic predisposition

with possible environmental contributions.

Historical Viral Hypothesis

A slow viral infection involving paramyxoviruses was historically proposed because of:

Long disease latency

Absence of systemic fever

Characteristic osteoclast abnormalities

However, an infectious cause has not been conclusively proven and is not considered an established explanation for most cases.

Pathophysiology

Paget disease begins with excessive:

Osteoclast-mediated bone resorption.

This is followed by a compensatory increase in:

Osteoblast activity and bone formation.

The resulting bone is produced rapidly and lacks the normal organized lamellar architecture.

Abnormal Bone

Pagetic bone may therefore become:

Enlarged

Hypervascular

Sclerotic

yet

Mechanically weaker than normal bone.

This explains the increased risk of:

Deformity

Fracture

Secondary arthritis

Diagnosis

Diagnosis is based on:

Clinical findings

Serum biochemical markers

Plain radiographs

and often

Bone scintigraphy.

Signs and Symptoms

Many patients are:

Asymptomatic.

The disease may be discovered incidentally through:

Elevated alkaline phosphatase

or

Abnormal radiographs.

Bone Pain

When symptomatic, the most common complaint is:

Bone pain.

Pagetic bone pain is often:

Deep

Aching

Persistent

and may be unrelated to activity.

Acute Increase in Pain

A sudden increase in pain should raise concern for:

Pathologic fracture

or, much less commonly,

Malignant transformation.

Skull Involvement

Skull disease may produce:

Frontal bossing

Increase in head size

Headache

Hearing loss

Hearing Loss

Conductive or sensorineural hearing impairment may develop because of:

Temporal bone involvement and alteration of the auditory apparatus.

Spine Involvement

Paget disease of the spine may cause:

Spinal stenosis

Radiculopathy

Neurogenic symptoms

due to vertebral enlargement and narrowing of the spinal canal or neural foramina.

Secondary Arthritis

Pagetic deformity may alter joint mechanics and produce secondary osteoarthritis.

The:

Hip

and

Knee

are particularly commonly affected.

Patients may develop:

Severe joint pain

Stiffness

Reduced walking tolerance

Physical Examination

Local Warmth

Affected superficial bone may feel:

Unusually warm

because of increased vascularity.

This is particularly noticeable in bones such as the:

Tibia.

Deformity

Long-standing disease may produce:

Bowing of long bones

Enlargement of the skull

Angular deformity

Joint Examination

Secondary arthritis may cause:

Restricted range of motion

Pain with motion

Crepitus

Gait disturbance

Hip involvement may significantly restrict:

Internal rotation and flexion.

Neurologic Examination

When the spine or skull is affected, assess for:

Weakness

Sensory change

Radicular symptoms

Gait abnormality

Hearing impairment

Laboratory Tests

Alkaline Phosphatase

The most useful routine biochemical marker is:

Serum alkaline phosphatase.

It is usually elevated when disease is metabolically active.

The level broadly reflects:

The extent and activity of abnormal bone remodeling.

Bone-Specific Alkaline Phosphatase

When total alkaline phosphatase is difficult to interpret because of liver disease, bone-specific markers may be useful.

Bone Resorption Markers

Markers of collagen breakdown may be elevated, including:

N-telopeptide

Hydroxyproline

Pyridinoline cross-links

These are used less commonly than alkaline phosphatase in routine clinical practice.

Serum Calcium

Serum calcium is usually:

Normal.

Hypercalcemia should prompt consideration of another or additional process, such as:

Prolonged immobilization

Hyperparathyroidism

Malignancy

Imaging

Plain Radiographs

Radiographs demonstrate characteristic abnormalities.

Findings may include:

Bone enlargement

Cortical thickening

Coarse trabeculation

Areas of osteolysis

Areas of sclerosis

Bone deformity

Flame-Shaped Lytic Lesion

A classic advancing osteolytic lesion may produce:

A flame-shaped or blade-of-grass radiolucent front, particularly in a long bone.

This is highly suggestive of Paget disease.

Skull Findings

Skull radiographs may demonstrate:

Patchy sclerosis

and the classic:

Cotton-wool appearance

in later stages.

The skull may also become enlarged and thickened.

Pelvic Findings

Pelvic involvement may produce:

Cortical and trabecular thickening

Pelvic brim sclerosis

Protrusio or secondary hip arthritis

Vertebral Findings

Pagetic vertebrae may become:

Enlarged

Sclerotic

with cortical thickening.

This can produce a characteristic:

Picture-frame vertebral appearance.

Bone Scintigraphy

Technetium bone scintigraphy demonstrates:

Increased radionuclide uptake in active lesions.

It is particularly useful for determining:

The full skeletal distribution of disease.

Role of Bone Scan

A bone scan helps determine whether disease is:

Monostotic

or

Polyostotic.

Areas identified on bone scan are often correlated with radiographs.

CT and MRI

CT or MRI may be used when evaluating:

Neurologic compression

Complex deformity

Possible malignant transformation

Atypical lesions

They are not required routinely in uncomplicated disease.

Pathological Findings

Pagetic bone demonstrates:

Very high remodeling activity

with numerous:

Osteoclasts

and

Osteoblasts.

Mosaic Pattern

Repeated cycles of resorption and deposition create numerous irregular:

Cement lines.

This produces the classic histologic:

Mosaic or jigsaw pattern of lamellar bone.

Vascularity

Affected bone is often:

Markedly hypervascular.

This can contribute to increased blood loss during surgery.

Structural Weakness

Although pagetic bone may be dense, it is mechanically disorganized and susceptible to:

Bowing

Microfracture

Pathologic fracture

Differential Diagnosis

Important alternatives include:

Metastatic bone disease

Fibrous dysplasia

Primary bone sarcoma

Paget-associated sarcoma

Metastatic Disease

Metastatic lesions may produce:

Mixed lytic and sclerotic changes

that resemble Paget disease.

Distribution, laboratory findings, imaging morphology, and clinical history help distinguish them.

Fibrous Dysplasia

Fibrous dysplasia may resemble Paget disease radiographically but generally occurs at a:

Younger age

and has different structural characteristics.

Paget-Associated Sarcoma

Malignant transformation should be suspected when a patient with longstanding Paget disease develops:

Rapidly increasing pain

A growing mass

New cortical destruction

A soft-tissue mass

Treatment

General Principles

Not every patient requires treatment.

Therapy is generally directed toward patients with:

Active symptomatic disease

High risk of complications

or

Disease in a location where progression may cause significant morbidity.

Indications for Treatment

Common reasons to treat include:

Pagetic bone pain

Neurologic compression related to active disease

Preparation for surgery involving pagetic bone

Selected lesions at high risk of fracture or deformity

Secondary Arthritis

Pain from secondary osteoarthritis may be treated using:

NSAIDs

Activity modification

Assistive devices

and standard osteoarthritis management.

Assistive Devices

A:

Cane

or

Walker

may help improve:

Balance

Gait stability

Pain control

Physical Therapy

Physical therapy may be used to improve:

Mobility

Strength

Balance

Postoperative rehabilitation

Exercise should be adapted to avoid excessive stress across severely deformed or weakened bone.

Medication

Bisphosphonates

Bisphosphonates are the principal medical treatment for active Paget disease.

They reduce:

Osteoclast-mediated bone resorption

and suppress excessive remodeling.

Mechanism

Bisphosphonates bind to:

Hydroxyapatite in bone

and are taken up by active osteoclasts, reducing their function and survival.

Common Agents

Modern treatment often uses potent agents such as:

Zoledronic acid

because a single intravenous dose can produce prolonged biochemical remission in many patients.

Other bisphosphonates may also be used.

Response to Therapy

Effective treatment generally causes:

Reduction in bone pain

and

Normalization or substantial reduction of alkaline phosphatase.

Bisphosphonate Adverse Effects

Potential effects vary by drug and may include:

Transient flu-like symptoms after intravenous treatment

Gastrointestinal irritation with oral drugs

Hypocalcemia

Renal function and vitamin D status should be considered before therapy.

Calcitonin

Calcitonin inhibits osteoclast function and was historically used frequently.

It may still be considered in selected patients who cannot receive bisphosphonates, but it is generally:

Less effective and less durable.

Potential adverse effects include:

Nausea

Flushing

Preoperative Medical Treatment

When major surgery is planned through highly active pagetic bone, treatment with antiresorptive medication may be considered beforehand to:

Reduce metabolic activity and potentially decrease intraoperative bleeding.

Surgery

The major orthopaedic indications for surgery are:

Joint replacement for secondary arthritis

Fixation of pathologic fractures

Correction of severe deformity

Joint Replacement

Total hip or knee arthroplasty can provide:

Excellent pain relief

and

Substantial functional improvement

in patients with advanced Paget-associated arthritis.

Fracture Fixation

Long-bone fractures often require stable fixation.

For diaphyseal fractures, an:

Intramedullary nail

is often advantageous because it spans a long segment of abnormal bone.

Deformity Correction

Severe long-bone bowing may require:

Corrective osteotomy.

Multiple osteotomies may occasionally be necessary to restore acceptable mechanical alignment.

Surgical Challenges

Operations involving pagetic bone may be complicated by:

Hypervascularity

Excessive bleeding

Bone deformity

Altered anatomy

Poor mechanical quality

Careful planning is therefore essential.

Follow-Up

Patients are followed according to:

Symptoms

Disease activity

Anatomic site

Treatment status

Laboratory Monitoring

Serum alkaline phosphatase is useful for following:

Response to therapy

and

Recurrence of metabolic activity.

Imaging Follow-Up

Plain radiographs are obtained when clinically indicated to monitor:

Deformity

Fracture

Arthritis

Possible malignant transformation

Routine annual radiographs of every involved site are not always necessary in stable asymptomatic disease.

Prognosis

Most patients with Paget disease are:

Asymptomatic or only mildly symptomatic

and have a near-normal life expectancy.

Complications depend primarily on:

The location and extent of affected bone.

Paget-Associated Sarcoma

Malignant transformation is rare, generally occurring in:

Less than 1% of patients.

When it occurs, the tumor is usually a high-grade sarcoma and carries a:

Poor prognosis.

Complications

Pathologic Fracture

Weakened pagetic bone is susceptible to:

Insufficiency and pathologic fractures.

These frequently occur through deformed weight-bearing bones.

Secondary Osteoarthritis

Abnormal alignment may increase loading across nearby joints and lead to:

Progressive degenerative arthritis.

Hearing Loss

Skull involvement may result in progressive:

Hearing impairment.

Neurologic Compression

Vertebral enlargement may cause:

Spinal stenosis

Radiculopathy

and occasionally

Spinal cord compression.

High-Output Cardiac Failure

Extensive active skeletal disease creates increased bone vascularity.

Very rarely, widespread disease can contribute to:

High-output cardiac failure.

Malignant Transformation

Warning features include:

New severe pain

Rapid enlargement

Cortical destruction

Soft-tissue mass

These should prompt advanced imaging and oncologic evaluation.

Patient Monitoring

Patients are commonly reassessed periodically, often:

Yearly in clinically active or significant disease.

Monitoring may include:

Symptoms

Serum alkaline phosphatase

Functional status

Targeted radiographs

Key Principle

Paget disease is a chronic disorder of excessively rapid and disorganized bone remodeling that produces enlarged, hypervascular, and mechanically weak bone.

Most patients do not require treatment, but active symptomatic disease is usually managed with:

Bisphosphonate therapy, while surgery is reserved for complications such as:

Advanced arthritis, pathologic fracture, severe deformity, neurologic compression, or suspected malignant transformation.

Orthopaedic Surgery - Osteosarcoma

Basics

Osteosarcoma is a high-grade primary malignant bone tumor characterized by malignant cells that directly produce osteoid or immature bone.

It is one of the most important primary bone sarcomas in:

Children

Adolescents

Young adults

and is particularly associated with periods of rapid skeletal growth.

Osteosarcoma can also occur in older adults, although in this population other primary bone malignancies, including chondrosarcoma, become relatively more common.

Synonym

Osteosarcoma is also called:

Osteogenic sarcoma.

Biological Behavior

Conventional high-grade osteosarcoma is an aggressive malignancy characterized by:

Rapid local invasion

Cortical destruction

Soft-tissue extension

Early hematogenous metastasis

The most common site of distant metastasis is the:

Lung.

Bone metastases may also occur.

Common Sites

Osteosarcoma most often develops in rapidly growing metaphyseal regions of long bones.

Historical distributions include:

Femur – approximately 41.5%

Tibia – approximately 16.5%

Humerus – approximately 15%

The classic location is:

Around the knee, particularly the distal femur and proximal tibia.

Classification

Osteosarcoma can be classified according to:

Anatomic location

Histologic grade

Degree of differentiation

Relationship to the bone surface or medullary cavity

Conventional High-Grade Intramedullary Osteosarcoma

This is the:

Most common form.

It arises within the medullary cavity and usually behaves aggressively.

Low-Grade or Well-Differentiated Intramedullary Osteosarcoma

This is uncommon and generally has:

Less aggressive histologic features

than conventional high-grade disease.

Surface Osteosarcomas

Surface osteosarcomas arise from the external surface of bone.

They include:

Parosteal osteosarcoma

Periosteal osteosarcoma

High-grade surface osteosarcoma

Parosteal Osteosarcoma

Parosteal osteosarcoma is the most common surface subtype.

It is generally:

Low grade

Well differentiated

and most frequently occurs around the:

Distal femur

although other metaphyseal locations can be involved.

Periosteal Osteosarcoma

Periosteal osteosarcoma is typically:

Intermediate grade

and arises from the bone surface beneath the periosteum.

It often demonstrates:

Prominent chondroid differentiation with malignant bone formation.

It more frequently involves the:

Diaphyseal or metadiaphyseal region.

High-Grade Surface Osteosarcoma

High-grade surface osteosarcoma is rare and behaves more aggressively than parosteal or many periosteal lesions.

Osteosarcoma of the Jaw

Osteosarcoma can involve the:

Mandible

or

Maxilla.

Jaw osteosarcomas often occur at an older age and may behave somewhat differently from conventional high-grade extremity osteosarcoma.

Secondary Osteosarcoma

Osteosarcoma can occasionally develop in previously abnormal bone.

Examples include:

Paget disease

Previous radiation exposure

Bone infarction

Fibrous dysplasia

and, rarely, other pre-existing skeletal disorders.

These are referred to as:

Secondary osteosarcomas.

Staging

Musculoskeletal sarcomas have historically been staged using the Enneking system.

Many conventional osteosarcomas present as:

Stage IIB – high-grade extracompartmental disease with soft-tissue extension

whereas patients with distant metastases are classified as:

Stage III.

Approximately 10–20% of patients historically have had detectable metastatic disease at diagnosis.

Epidemiology

Osteosarcoma occurs most commonly during:

The second decade of life.

The median age at presentation has historically been approximately:

13–17 years.

A slight male predominance has been reported.

Incidence

Primary sarcomas of bone are uncommon.

Osteosarcoma accounts for only a small fraction of all cancers but is one of the more common primary malignant bone tumors in children and adolescents.

Older U.S. estimates described several hundred new osteosarcoma cases annually.

Risk Factors

Most patients have no identifiable predisposing condition.

Recognized risk factors include:

Previous therapeutic radiation

Paget disease of bone

Bone infarction

Certain hereditary cancer syndromes

Pre-existing abnormal bone in selected disorders

Etiology

The cause of conventional high-grade osteosarcoma is usually unknown.

Its increased frequency during periods of:

Rapid skeletal growth

has long suggested a relationship between growth rate and tumor development, although rapid growth itself is not considered a direct cause.

Genetic Abnormalities

Osteosarcoma frequently contains complex genomic abnormalities.

Important tumor-suppressor pathways include:

RB1

and

TP53.

Retinoblastoma

Patients with hereditary retinoblastoma have an increased risk of developing osteosarcoma because of germline abnormalities involving the:

RB1 tumor-suppressor gene.

The risk may be further increased after radiation exposure.

Other Hereditary Syndromes

Osteosarcoma can also occur more frequently in rare cancer-predisposition syndromes involving:

TP53

and other genes controlling:

Cell-cycle regulation and DNA repair.

Associated Conditions

Important associated conditions include:

Hereditary retinoblastoma

Paget disease

Prior radiotherapy

Certain hereditary cancer syndromes

Diagnosis

Diagnosis is based on:

Clinical features

Plain radiographs

MRI

Staging studies

and

Biopsy.

Signs and Symptoms

The most common symptoms are:

Pain

and

Swelling.

Pain

Pain usually develops:

Gradually

and becomes:

Persistent and progressive.

It may initially be attributed to:

Sports activity

Minor trauma

or

Growing pains.

Night Pain

Many patients report:

Pain at night, sometimes severe enough to interrupt sleep.

Persistent night pain in a child or adolescent with a focal bone lesion should prompt further evaluation.

Swelling

As the tumor expands through the cortex, patients may notice:

Localized swelling

or

A palpable mass.

Physical Examination

A soft-tissue mass may be:

Firm

Tender

Warm

and associated with:

Reduced motion of the adjacent joint.

Range of Motion

Large lesions near a joint may cause:

Painful limitation of motion

because of local mass effect and inflammation.

Direct joint invasion is relatively uncommon early because articular cartilage and other joint structures initially act as barriers.

Pathologic Fracture

Occasionally, patients present with a:

Pathologic fracture through the tumor.

This complicates local treatment because fracture hematoma may contaminate surrounding tissue planes.

Staging Evaluation

Once osteosarcoma is suspected or diagnosed, staging commonly includes:

MRI of the primary tumor

CT of the chest

and

Whole-body assessment for additional skeletal disease, traditionally with bone scintigraphy and increasingly with other appropriate staging modalities.

Biopsy

Definitive diagnosis requires tissue biopsy.

The biopsy should be planned by or in consultation with the:

Musculoskeletal oncologic surgeon who will perform definitive resection.

Poor biopsy placement can contaminate compartments and complicate limb-salvage surgery.

Laboratory Tests

There is no single diagnostic blood test for osteosarcoma.

Alkaline Phosphatase

Serum alkaline phosphatase may be elevated.

A markedly elevated pretreatment value has historically been associated with:

Greater tumor burden and less favorable prognosis.

Serial measurements can occasionally help monitor disease when the level was elevated initially.

Lactate Dehydrogenase

Serum LDH may also be elevated.

An elevated LDH has likewise been associated with:

Higher tumor burden and poorer prognosis in some studies.

Imaging

Plain Radiographs

Osteosarcoma most commonly arises in the:

Metaphysis of a long bone.

Typical radiographic features include a mixture of:

Bone destruction

Tumor bone formation

Aggressive periosteal reaction

Soft-tissue mass

Destructive Bone Lesion

The classic lesion is:

Aggressively destructive while simultaneously producing abnormal mineralized osteoid or bone.

There may be:

Poorly defined margins

Cortical destruction

Mixed lytic and sclerotic change

Tumor Bone Formation

Malignant osteoid may appear radiographically as:

Cloud-like or dense mineralization

within the lesion or soft-tissue mass.

Codman Triangle

Rapid tumor growth may lift the periosteum away from the cortex.

Reactive bone formation at the edge of this elevated periosteum can produce a:

Codman triangle.

This is an aggressive periosteal reaction but is not specific to osteosarcoma.

Sunburst Appearance

Radiating spicules of mineralized tumor or reactive bone extending perpendicular to the cortex can create the classic:

Sunburst or sunray appearance.

Again, this is suggestive but not pathognomonic.

Soft-Tissue Extension

A mineralized soft-tissue mass strongly supports an aggressive bone-forming lesion.

MRI

MRI is the preferred modality for defining:

Intramedullary tumor extent

Soft-tissue extension

Relationship to neurovascular structures

Relationship to the joint

Skip lesions within the involved bone

This information is essential for surgical planning.

Chest CT

CT of the chest is important because:

The lungs are the most common site of metastasis.

Small pulmonary nodules may be detected before they are visible on routine chest radiography.

Skeletal Staging

Whole-body imaging is used to evaluate for:

Bone metastases

and

Additional skeletal lesions.

Pathological Findings

The defining histologic feature of osteosarcoma is:

Malignant mesenchymal cells directly producing osteoid or immature bone.

This malignant osteoid is required for diagnosis.

Histologic Subtypes

Conventional osteosarcoma may demonstrate varying dominant patterns.

Broad histologic patterns include:

Osteoblastic

Chondroblastic

Fibroblastic

Regardless of subtype, malignant osteoid production is the essential feature.

Differential Diagnosis

Important differential diagnoses include:

Osteomyelitis

Ewing sarcoma

Giant cell tumor

Metastatic bone disease

Eosinophilic granuloma

Other bone-forming tumors

Osteomyelitis

Infection may mimic osteosarcoma because both can produce:

Pain

Swelling

Bone destruction

Periosteal reaction

Clinical findings, inflammatory markers, MRI, and biopsy help distinguish the two.

Ewing Sarcoma

Ewing sarcoma frequently affects children and adolescents and can also present with:

Pain

Swelling

Aggressive bone destruction

However, its typical location and histologic appearance differ from osteosarcoma.

Giant Cell Tumor

Giant cell tumor generally occurs in:

Skeletally mature patients

and typically involves the:

Epiphysis extending to the subchondral bone.

Metastatic Disease

Metastatic bone lesions become increasingly important in the differential diagnosis in older adults.

Treatment

General Principles

Any patient with an aggressive destructive lesion that also demonstrates:

Tumor bone formation

should be referred promptly to an experienced:

Musculoskeletal oncology team.

Biopsy or definitive surgery should not be undertaken casually before appropriate staging and multidisciplinary planning.

Activity

Once osteosarcoma is suspected, the affected extremity should be protected from:

High-impact activity

Falls

Excessive weight bearing

to minimize the risk of:

Pathologic fracture.

Lower-Extremity Lesions

Patients with tumors of the lower extremity are often instructed to use:

Crutches or another protected-weight-bearing aid.

Upper-Extremity Lesions

For upper-extremity tumors, efforts should be made to maintain:

Hand

Wrist

and

Elbow function

while avoiding activities that risk fracture through the tumor.

Chemotherapy

Modern treatment of conventional high-grade osteosarcoma combines:

Systemic chemotherapy

with

Wide surgical resection.

Neoadjuvant Chemotherapy

Chemotherapy is often administered:

Before surgery

to treat microscopic metastatic disease and begin systemic tumor control.

A typical preoperative phase lasts several weeks.

Common Chemotherapy Agents

Common multiagent regimens may include combinations of:

High-dose methotrexate

Doxorubicin

Cisplatin

with other agents used in selected protocols.

The exact regimen depends on:

Age

Tumor characteristics

Treatment center

National or cooperative-group protocol

Adjuvant Chemotherapy

Chemotherapy is continued after surgery for several months.

Postoperative treatment addresses:

Micrometastatic disease

and reduces the risk of systemic recurrence.

Histologic Response

The amount of tumor necrosis following preoperative chemotherapy is an important prognostic factor.

A high percentage of necrosis generally indicates:

A favorable chemotherapy response.

Surgery

Historically, amputation was the standard treatment.

With modern imaging, chemotherapy, reconstruction, and oncologic surgical techniques, most appropriately selected patients can undergo:

Limb-salvage surgery.

Wide Resection

The primary tumor must be removed with:

A wide margin of uninvolved tissue.

The goal is complete local control without leaving microscopic tumor at the surgical margin.

Limb Salvage

Limb salvage is feasible in a large majority of patients when:

Adequate margins can be achieved

Critical neurovascular structures can be preserved or reconstructed

and

The limb can remain functional.

Reconstruction

After tumor resection, the skeletal defect may be reconstructed using:

Large-segment endoprostheses

Allograft

Allograft-prosthetic composites

Other biological reconstruction techniques

depending on the site and age of the patient.

Amputation

Amputation may still be required when:

Adequate oncologic margins cannot be achieved with limb salvage

Major neurovascular contamination exists

Severe infection or tissue loss prevents reconstruction

Functional limb salvage would be inferior to amputation

Pulmonary Metastasectomy

Selected patients with resectable lung metastases may benefit from:

Surgical removal of pulmonary metastatic lesions, particularly when complete resection is possible.

Follow-Up

Long-term surveillance is required because osteosarcoma can recur:

Locally

or

At distant sites.

The lungs are monitored especially closely.

Prognosis

Before effective chemotherapy, survival for high-grade osteosarcoma was poor, with historical 5-year survival rates of only:

Approximately 20–30%.

The major problem was occult pulmonary metastatic disease.

Modern Outcomes

For patients with:

Localized high-grade disease

treated with multiagent chemotherapy and complete surgical resection, long-term survival is substantially better, historically in the range of:

Approximately 60–70% or higher in selected contemporary series.

Outcomes are significantly worse when metastatic disease is present at diagnosis.

Favorable Prognostic Factors

Better outcomes are associated with:

Localized disease

Complete surgical resection

Good histologic response to chemotherapy

Smaller tumor burden

Resectable pulmonary metastases when present

Poor Prognostic Factors

Less favorable factors include:

Metastatic disease at diagnosis

Large tumor volume

Poor chemotherapy response

Elevated alkaline phosphatase or LDH in some series

Inability to achieve clear surgical margins

Complications

Pulmonary Metastases

The lungs are the most frequent site of metastatic spread.

Pulmonary metastases may occur:

At diagnosis

or

During follow-up after treatment.

Most recurrences occur within the first several years, although later recurrence is possible.

Bone Metastases

Osteosarcoma may also metastasize to:

Other bones.

Multifocal skeletal involvement generally indicates a less favorable prognosis.

Local Recurrence

Local recurrence after limb-salvage treatment is uncommon when adequate margins are obtained but remains a serious complication.

Older series reported local recurrence in approximately:

5–10% of patients.

Pathologic Fracture

Fracture through the tumor can:

Increase pain

Complicate local control

Contaminate surrounding tissues

It does not automatically require amputation, but it may make limb salvage more difficult.

Infection

Major reconstruction after tumor resection carries a meaningful risk of:

Deep infection.

This may require:

Débridement

Revision reconstruction

or occasionally

Amputation.

Prosthetic Complications

Endoprosthetic reconstruction may be complicated by:

Aseptic loosening

Mechanical failure

Periprosthetic fracture

Joint instability

Wear

Need for revision surgery

Wound Complications

Large oncologic resections may lead to:

Wound breakdown

Skin necrosis

Delayed healing

particularly after extensive soft-tissue resection.

Chemotherapy-Related Complications

Systemic treatment may cause:

Myelosuppression

Infection

Renal toxicity

Cardiac toxicity

Hearing impairment

and other drug-specific adverse effects.

Patient Monitoring

Post-treatment surveillance should assess for:

Pulmonary metastasis

Local recurrence

Bone metastasis

Reconstruction failure

Long-term chemotherapy effects

Chest Surveillance

Because pulmonary metastases are particularly common, chest imaging is performed regularly.

Historically, chest CT was obtained approximately every:

3–4 months during the first 2 years, with progressively longer intervals afterward.

The exact modern surveillance schedule depends on:

Treatment protocol

Disease stage

Age

Institutional practice

Local Imaging

Plain radiographs of the treated extremity are used to assess:

Local recurrence

Prosthetic or graft integrity

Fracture

Mechanical complications

MRI may be added when recurrence is suspected.

Key Principle

Osteosarcoma is an aggressive malignant bone-forming tumor that most commonly arises in the metaphyses of rapidly growing long bones in adolescents.

The defining pathologic feature is:

Malignant osteoid production.

Optimal treatment requires:

Prompt referral to musculoskeletal oncology, carefully planned biopsy, systemic multiagent chemotherapy, wide surgical resection, appropriate reconstruction, and long-term surveillance for pulmonary and local recurrence.

Orthopaedic Surgery - Osteoporosis

Basics

Osteoporosis is a systemic skeletal disorder characterized by reduced bone mass and deterioration of bone microarchitecture, resulting in decreased bone strength and an increased risk of fragility fracture.

The disease affects both:

Cortical bone

and

Trabecular bone.

Clinically important fractures most commonly involve the:

Vertebrae

Hip

Distal radius

Proximal humerus

Bone Mineral Density Definition

Bone mineral density is commonly measured using dual-energy X-ray absorptiometry (DEXA or DXA).

The T-score compares the patient’s bone mineral density with that of a healthy young adult reference population.

In postmenopausal women and men aged 50 years or older:

Normal bone density: T-score ≥ –1.0

Low bone mass or osteopenia: T-score between –1.0 and –2.5

Osteoporosis: T-score ≤ –2.5

A fragility fracture may establish clinically important osteoporosis even when the T-score is higher than –2.5.

Z-Score

The Z-score compares the patient’s bone mineral density with that expected for:

People of the same age and sex.

It is particularly useful in:

Premenopausal women

Men younger than 50 years

Children and adolescents

A markedly low Z-score should prompt investigation for secondary causes of reduced bone density.

Prevention

Prevention focuses on preserving bone mass and reducing fracture risk.

Important measures include:

Adequate calcium and vitamin D intake

Regular weight-bearing exercise

Resistance training

Smoking cessation

Avoidance of excessive alcohol

Fall prevention

Treatment of diseases and medications that accelerate bone loss

Nutrition

Adequate nutrition is particularly important during:

Childhood

Adolescence

Early adulthood

because peak bone mass achieved during these periods influences future osteoporosis risk.

Epidemiology

Osteoporosis is a major cause of fragility fractures worldwide.

Older estimates attributed approximately 1.3 million fractures annually to osteoporosis in the United States, with substantial numbers involving the:

Spine

Hip

and

Wrist.

The actual burden has increased as populations have aged.

Age

Fracture risk rises progressively with age and increases particularly sharply in older adults.

Patients older than approximately:

75 years

have a substantially increased risk of hip and other major osteoporotic fractures.

Sex

After approximately age 50, women have a considerably greater lifetime risk of fragility fracture than men.

This is related partly to:

Lower peak bone mass

Accelerated postmenopausal bone loss

Longer life expectancy

Risk Factors

Important risk factors include:

Increasing age

Female sex

Low body weight

Previous fragility fracture

Family history of osteoporosis or hip fracture

Early menopause

Prolonged amenorrhea

Smoking

Excessive alcohol intake

Physical inactivity

Low calcium or vitamin D intake

Ethnicity

Historically, osteoporosis has been recognized particularly often in:

White populations of Northern European ancestry

and

Asian populations.

However, osteoporosis occurs in all racial and ethnic groups, and fracture risk should be assessed individually.

Reproductive Risk Factors

Factors associated with reduced lifetime estrogen exposure include:

Late menarche

Early menopause

Premature ovarian insufficiency

Prolonged amenorrhea

Historically, nulliparity has also been discussed as a possible risk factor.

Low Body Weight

A small body frame or low body mass is associated with:

Lower bone mass and increased fracture risk.

Older criteria sometimes used a body weight below approximately:

127 lb or 58 kg

as a risk marker.

Female Athlete Triad

In physically active women, prolonged low energy availability may contribute to:

Menstrual dysfunction

Reduced bone mineral density

and

Stress fracture risk.

This was historically termed the Female Athlete Triad and is now understood within the broader concept of relative energy deficiency in sport.

Genetics

Bone density has an important hereditary component.

Multiple genes influence:

Peak bone mass

Bone turnover

Calcium metabolism

Fracture susceptibility

Candidate pathways have included genes involving:

Vitamin D signaling

Type I collagen

Wnt signaling, including LRP5/6

The inheritance pattern is complex and polygenic.

Etiology

Osteoporosis may be:

Primary

or

Secondary.

Primary Osteoporosis

Primary osteoporosis includes:

Postmenopausal osteoporosis

and

Age-related osteoporosis.

In many patients, no single secondary cause is identified.

Secondary Osteoporosis

Secondary osteoporosis results from another disease, nutritional abnormality, medication, or lifestyle factor.

Nutritional Causes

Potential contributors include:

Low calcium intake

Vitamin D deficiency

Malnutrition

Restrictive diets

Malabsorption

Excessive alcohol use

Lifestyle Causes

Important lifestyle factors include:

Smoking

Physical inactivity

Low weight-bearing activity

Excessive alcohol consumption

Medical Causes

Secondary osteoporosis may occur with:

Type 1 diabetes mellitus

Cushing syndrome

Chronic kidney disease

Inflammatory bowel disease

Cystic fibrosis

Primary hyperparathyroidism

Hyperthyroidism

Anorexia nervosa

Celiac disease

Idiopathic hypercalciuria

Premature ovarian insufficiency

Other chronic inflammatory, endocrine, gastrointestinal, and hematologic disorders may also contribute.

Medication-Related Causes

Medications associated with bone loss include:

Chronic glucocorticoids

Certain anticonvulsants

Some chemotherapy agents

Long-term excess thyroid hormone replacement

Prolonged lithium therapy in selected patients

Other drugs may also affect bone metabolism depending on dose and duration.

Diagnosis

Signs and Symptoms

Osteoporosis itself is usually:

Asymptomatic until a fracture occurs.

A fragility fracture should immediately raise suspicion for underlying osteoporosis.

Fragility Fracture

A fragility fracture is one occurring after:

Minimal trauma, such as a fall from standing height or less.

Common sites include:

Vertebra

Hip

Distal radius

Proximal humerus

History

Important historical features include:

Prior low-energy fracture

Loss of height

Back pain

Family history of hip fracture

Early menopause

Smoking

Alcohol intake

Diet

Physical activity

Long-term steroid use

Endocrine or gastrointestinal disease

Physical Examination

Many patients have no specific findings until vertebral fractures develop.

Vertebral Compression Fractures

Multiple vertebral compression fractures may cause:

Progressive loss of height

Thoracic kyphosis

Reduced lumbar lordosis

Chronic back pain

Postural Changes

Severe vertebral osteoporosis may produce:

Forward stooping

Reduced trunk height

Prominent abdomen

Altered sagittal balance

DEXA

DEXA is the standard test for measuring bone mineral density.

Common sites include:

Lumbar spine

Femoral neck

Total hip

In selected circumstances, the:

Distal radius

may also be measured.

T-Score Interpretation

The T-score represents the number of standard deviations the patient’s bone mineral density lies above or below the mean of a healthy young reference population.

A lower T-score indicates:

Lower bone density and generally higher fracture risk.

Fracture Risk Assessment

Bone mineral density should be interpreted together with clinical risk factors.

Tools such as fracture-risk calculators can estimate the probability of:

Hip fracture

and

Major osteoporotic fracture

over a defined period.

Laboratory Evaluation

Laboratory testing is used mainly to identify:

Secondary causes of osteoporosis.

Basic Laboratory Studies

Common initial tests include:

CBC

Comprehensive metabolic panel

Serum calcium

Creatinine

Liver function tests when appropriate

Thyroid-stimulating hormone

Additional Testing

Depending on history and examination, testing may include:

25-hydroxyvitamin D

Parathyroid hormone

Phosphate

Serum protein electrophoresis

Testosterone in men

Celiac screening

24-hour urinary calcium

Vitamin D and Parathyroid Hormone

Measurement of:

25-hydroxyvitamin D

and

PTH

is particularly helpful in patients with:

Older age

Chronic kidney disease

Malabsorption

Liver disease

Anticonvulsant use

or suspected metabolic bone disease.

Multiple Myeloma Screening

When unexplained osteoporosis, anemia, renal dysfunction, hypercalcemia, or bone pain is present, evaluation for:

Multiple myeloma

may be appropriate.

Normal routine laboratory studies reduce suspicion but do not absolutely exclude myeloma.

Imaging

Plain Radiographs

Plain radiographs are insensitive for early osteoporosis.

Bone loss may not become visually apparent until approximately:

30% or more of bone mineral has been lost.

Spinal Findings

Moderate or severe osteoporosis may demonstrate:

Generalized osteopenia

Vertebral compression fractures

Biconcave vertebral bodies

Anterior wedging

Long-Bone Findings

Long bones may demonstrate:

Cortical thinning

Relative widening of the medullary canal

Generalized reduction in bone density

Occult Fractures

Fragility fractures may occasionally be occult on initial radiographs.

Additional imaging may include:

MRI

CT

Bone scintigraphy

or

Repeat radiographs

depending on the suspected site.

MRI is particularly useful for detecting:

Occult hip fracture

Acute vertebral compression fracture

Sacral insufficiency fracture

Pathophysiology

Normal bone undergoes continuous remodeling.

The remodeling cycle includes:

Osteoclastic resorption of old bone

followed by

Recruitment of osteoblasts

Deposition of new osteoid

and

Mineralization.

Remodeling Imbalance

In osteoporosis, bone resorption exceeds bone formation over time.

Each remodeling cycle results in:

A small net loss of bone mass.

Repeated cycles eventually reduce:

Trabecular connectivity

Cortical thickness

Mechanical strength

Postmenopausal Bone Loss

Estrogen deficiency increases:

Osteoclast activity and bone turnover.

This produces accelerated bone loss, particularly in the years following menopause.

Hyperparathyroidism

Excess parathyroid hormone can increase:

Bone-remodeling activation and resorption, contributing to secondary osteoporosis.

Differential Diagnosis

Important differential diagnoses include:

Osteomalacia

Multiple myeloma

Leukemia

Paget disease of bone

Osteogenesis imperfecta

Hyperparathyroid bone disease

Osteomalacia

Osteomalacia represents defective:

Mineralization of osteoid

rather than simply reduced bone quantity.

Vitamin D deficiency is a common cause.

Neoplastic Disease

Myeloma and other malignancies may produce:

Diffuse osteopenia

Pathologic fractures

Bone pain

and should be considered when clinical features are atypical.

Treatment

General Principles

Treatment aims to:

Prevent fractures

Maintain or improve bone density

Reduce fall risk

Correct secondary causes

Preserve mobility and independence

Exercise

Regular exercise is important.

Beneficial programs include:

Weight-bearing exercise

Resistance training

Balance training

These interventions may produce modest improvements in bone mineral density and reduce fall risk.

Fall Prevention

Particularly in older adults, fracture prevention requires attention to:

Vision

Footwear

Home hazards

Balance impairment

Sedating medications

Muscle weakness

Calcium

Adequate calcium intake should be ensured, preferably through diet when possible.

Total daily intake from food and supplements is commonly targeted around:

1,000–1,200 mg per day in many older adults, depending on age and sex.

Excessive supplementation should be avoided.

Vitamin D

Vitamin D should be sufficient to support:

Calcium absorption and bone mineralization.

Supplementation is individualized according to:

Diet

Sun exposure

Serum 25-hydroxyvitamin D

Age

Comorbidities

Older fixed recommendations often used approximately 800 IU daily.

Bisphosphonates

Bisphosphonates are first-line antiresorptive medications for many patients at elevated fracture risk.

They act primarily by:

Reducing osteoclast-mediated bone resorption.

Common Bisphosphonates

Examples include:

Alendronate

Risedronate

Ibandronate

Zoledronic acid

Administration may be:

Weekly

Monthly

or

Intravenous at longer intervals, depending on the drug.

Fracture Reduction

Bisphosphonates reduce the risk of:

Vertebral fracture

and, for several agents,

Hip and other nonvertebral fractures.

The exact degree of risk reduction varies by medication and patient population.

Bisphosphonate Requirements

Patients should have adequate:

Calcium

and

Vitamin D

and clinically important hypocalcemia should be corrected before treatment.

Bisphosphonate Adverse Effects

Potential complications include:

Upper gastrointestinal irritation with oral agents

Acute-phase reaction after intravenous therapy

Hypocalcemia

Rare long-term complications include:

Atypical femoral fracture

and

Medication-related osteonecrosis of the jaw.

Denosumab

Denosumab is a monoclonal antibody against:

RANKL.

It suppresses osteoclast formation and activity.

It is useful in selected patients with:

High fracture risk

or intolerance to other therapies.

Treatment should not be stopped abruptly without another antiresorptive strategy because rapid rebound bone loss and vertebral fractures may occur.

Selective Estrogen Receptor Modulators

SERMs such as:

Raloxifene

can reduce the risk of:

Vertebral fractures

in selected postmenopausal women.

They have less established benefit for:

Hip fracture prevention.

Estrogen Therapy

Estrogen reduces postmenopausal bone loss and fracture risk.

However, routine use solely for osteoporosis treatment is limited by risks that may include:

Venous thromboembolism

Stroke

Cardiovascular effects

Certain hormone-sensitive cancers

depending on formulation and patient characteristics.

Calcitonin

Calcitonin inhibits osteoclast activity.

Its role in long-term osteoporosis treatment is now limited because:

Fracture-prevention benefit is modest or uncertain compared with newer therapies.

Anabolic Therapy

Bone-forming therapies may be used in patients at very high fracture risk.

Examples include:

Teriparatide

Abaloparatide

and, in selected patients,

Romosozumab.

Teriparatide

Teriparatide is a recombinant parathyroid hormone analog that stimulates:

New bone formation

when administered intermittently.

It is generally reserved for patients with:

Severe osteoporosis

Multiple fragility fractures

Very high fracture risk

or failure of other therapy.

Romosozumab

Romosozumab inhibits:

Sclerostin

and has both:

Anabolic and antiresorptive effects.

It may be considered in selected very-high-risk patients, with attention to cardiovascular risk.

Surgery

Surgical treatment is directed toward:

Completed or impending fragility fractures, rather than the osteoporosis itself.

Hip Fractures

Hip fractures usually require operative management such as:

Internal fixation

or

Arthroplasty

depending on fracture pattern and patient factors.

Vertebral Compression Fractures

Most osteoporotic vertebral fractures are initially treated nonoperatively with:

Analgesia

Activity modification

Gradual mobilization

Osteoporosis treatment

Vertebroplasty and Kyphoplasty

Vertebral cement augmentation may be considered in carefully selected patients with:

Persistent severe pain from an acute or subacute vertebral compression fracture despite appropriate conservative treatment.

Routine prophylactic cement injection into unfractured vertebrae is not recommended.

Follow-Up

Patients require periodic reassessment of:

Fracture risk

Medication adherence

Adverse effects

Falls

Calcium and vitamin D status

Secondary causes

Repeat DEXA

Bone density testing is generally repeated after an interval sufficient to detect clinically meaningful change.

The interval is individualized according to:

Baseline bone density

Treatment

Age

Fracture risk

Referral

Referral to an endocrinologist or metabolic bone specialist should be considered for:

Very low bone density

Recurrent fractures despite therapy

Unusual osteoporosis at a young age

Suspected secondary osteoporosis

Complex endocrine or metabolic disease

A T-score alone should not be the sole determinant for referral.

Prognosis

Earlier recognition and treatment can substantially reduce fracture risk.

The prognosis depends on:

Baseline bone density

Age

Previous fractures

Fall risk

Secondary causes

Response to therapy

Complications

The major complication is:

Fragility fracture.

Vertebral Fractures

Vertebral fractures can lead to:

Chronic pain

Progressive kyphosis

Loss of height

Reduced pulmonary capacity

Impaired mobility

Hip Fractures

Hip fractures are particularly serious and may result in:

Loss of independence

Prolonged rehabilitation

Institutionalization

Increased mortality

Wrist and Upper-Extremity Fractures

Distal radius and proximal humerus fractures may impair:

Self-care

Balance aid use

Upper-extremity function

Patient Monitoring

Patients should be monitored for:

New fragility fractures

Loss of height

Back pain

Falls

Medication adverse effects

Changes in bone mineral density

Evidence of secondary osteoporosis

Key Principle

Osteoporosis is a systemic disorder of reduced bone strength caused by low bone mass and deterioration of bone microarchitecture.

Management focuses on:

Identifying patients at high fracture risk, correcting secondary causes, ensuring adequate calcium and vitamin D, encouraging weight-bearing and resistance exercise, reducing falls, and using antiresorptive or anabolic therapy when indicated.

Orthopaedic Surgery - Osteomyelitis

Basics

Osteomyelitis is an infection and inflammatory process involving bone and bone marrow.

It may occur through:

Hematogenous spread

Direct inoculation after trauma or surgery

or

Contiguous spread from adjacent soft-tissue infection.

One of the most commonly used classifications is based on the duration and clinical pattern of infection.

Classification

Acute Osteomyelitis

Acute osteomyelitis most commonly results from:

Hematogenous spread of bacteria.

In children, the infection usually begins in the:

Metaphysis of a long bone.

Causative Organisms in Acute Osteomyelitis

Staphylococcus aureus is the most common organism across most pediatric age groups.

In neonates, other important organisms include:

Group B Streptococcus

Gram-negative bacilli

depending on age and clinical circumstances.

Subacute Osteomyelitis

Subacute osteomyelitis accounts for a substantial proportion of primary bone infections.

It is characterized by:

Insidious onset

Milder symptoms

Longer duration

Less impressive laboratory abnormalities

The most common organisms are usually:

Staphylococcal species.

A localized subacute intraosseous abscess is often referred to as a:

Brodie abscess.

Chronic Osteomyelitis

Chronic osteomyelitis is a longstanding infection characterized by:

Persistent or recurrent inflammation

Necrotic bone

Sinus formation in some patients

Sequestrum formation

Staphylococcus aureus remains an important causative organism.

Chronic disease often requires surgical:

Débridement or curettage of devitalized bone.

Alternative Classification Systems

Osteomyelitis may also be classified according to:

Patient age

Causative organism

Route of infection

Anatomic extent

Categories may include:

Neonatal, pediatric, or adult osteomyelitis

Pyogenic or granulomatous infection

Hematogenous, direct inoculation, or contiguous-spread infection

Synonym

Osteomyelitis is commonly referred to as:

Bone infection.

Epidemiology

Acute hematogenous osteomyelitis occurs more commonly in children than adults.

Peak incidence is generally during:

Later childhood in the first decade of life.

Some historical studies have suggested seasonal variation, with more cases occurring during:

Late summer and early autumn.

Sex Distribution

A slight male predominance has been described.

One possible explanation is greater exposure to:

Minor trauma and activity-related skeletal injury.

Prevalence

Osteomyelitis affects fewer than approximately:

1% of children.

It remains an important diagnosis because delayed recognition can result in major skeletal complications.

Risk Factors

Most children who develop acute hematogenous osteomyelitis are otherwise healthy.

Potential risk factors include:

Recent trauma

Immunocompromise

Malnutrition

Recent systemic infection

Sickle cell disease

Open wounds or surgery

Antecedent Trauma

A history of minor trauma is common but does not necessarily cause the infection.

Trauma may:

Draw attention to the area

or potentially alter local blood flow, facilitating bacterial seeding.

Sickle Cell Disease

Patients with sickle cell disease have an increased risk of osteomyelitis because:

Bone infarction and altered splenic function may predispose to infection.

However, acute bone pain in a patient with sickle cell disease is still more commonly caused by:

Vaso-occlusive infarction

than infection.

Organisms in Sickle Cell Disease

Staphylococcus aureus remains an important pathogen.

Salmonella species are also classically associated with osteomyelitis in patients with sickle cell disease.

Etiology

The exact reason one child develops hematogenous osteomyelitis while another does not is often unclear.

Possible contributing factors include:

Transient bacteremia

Minor trauma

Altered local blood flow

Impaired host defenses

Most affected children have no major underlying disorder.

Associated Conditions

Nearly half of affected children may have a recent or concurrent infection, such as:

Upper respiratory infection

Viral illness

or another transient infectious process.

This may provide a source for transient bacteremia.

Diagnosis

Diagnosis requires a combination of:

Clinical suspicion

Laboratory testing

Imaging

and, when possible,

Microbiologic identification of the organism.

Signs and Symptoms

The most common symptom is:

Localized bone pain.

Other findings may include:

Swelling

Warmth

Erythema

Tenderness

Reduced movement of the adjacent joint

Limp

Refusal to bear weight

Fever

Fever may occur, but:

Its absence does not exclude osteomyelitis.

Some children, particularly neonates and patients with subacute infection, may have little or no fever.

Infants and Young Children

Children who cannot describe their symptoms may present with:

Refusal to walk

Limping

Failure to use a limb

Irritability with movement

Pseudoparalysis

A high index of suspicion is particularly important in:

Neonates.

Classical Diagnostic Criteria

Older diagnostic approaches considered osteomyelitis strongly supported when at least two of the following were present:

Pus aspirated from bone

Positive blood or bone culture

Localized pain, swelling, warmth, and restricted movement

Imaging changes compatible with osteomyelitis

Modern diagnosis relies on the overall clinical, microbiologic, and imaging picture rather than a rigid numerical rule.

History

Important questions include:

When did the pain begin?

Was there preceding trauma?

Has there been fever?

Has the child recently been ill?

Is the patient refusing to bear weight?

Was there recent surgery, injection, or penetrating injury?

Is there underlying sickle cell disease or immune compromise?

Physical Examination

The goal is to:

Localize the infected bone

and

Identify associated joint or systemic involvement.

General Appearance

The child may appear:

Well but irritable

or

Systemically ill and lethargic

depending on the severity and duration of infection.

Observation Before Palpation

Before touching the child, observe:

Spontaneous movement

Limb position

Willingness to bear weight

Use of the affected extremity

Reduced spontaneous use may be an important diagnostic clue.

Tenderness

Palpation usually reveals:

Focal metaphyseal tenderness.

In young or frightened children, a parent may help localize the painful region.

Local Inflammatory Findings

Typical findings include:

Warmth

Swelling

Erythema

Tenderness

These are often most pronounced over the metaphysis.

Deeply Located Bones

In areas with substantial overlying muscle, such as the:

Femur

visible erythema may be absent despite significant infection.

Joint Examination

Adjacent joints should be examined carefully for:

Effusion

Pain with passive motion

Reduced range of motion

because septic arthritis may coexist with osteomyelitis, particularly in infants.

Laboratory Tests

White Blood Cell Count

The WBC count is not sufficiently sensitive to rule out osteomyelitis.

A normal value does not exclude infection.

If elevated, however, it supports the diagnosis in the appropriate clinical setting.

Blood Cultures

Blood cultures should be obtained:

Early and preferably before antibiotics are started, provided this does not delay treatment in an ill patient.

Blood cultures are positive in a substantial proportion of cases, historically around:

50%.

A positive blood culture may identify the causative organism without requiring direct bone aspiration.

ESR

The erythrocyte sedimentation rate is a nonspecific marker of inflammation.

It often rises within:

48–72 hours

and may remain elevated for several weeks.

Because it normalizes slowly, it is less useful than CRP for assessing rapid treatment response.

C-Reactive Protein

CRP is particularly useful because it:

Rises earlier

and

Returns toward normal more rapidly

than ESR.

It is therefore valuable for monitoring response to therapy.

Normal ranges vary among laboratories.

Aspiration and Biopsy

Aspiration of the infected site may be performed to identify the organism.

Samples should be sent for:

Gram stain

Aerobic bacterial culture

and additional studies when clinically indicated.

Special Cultures

In selected patients, samples may also be sent for:

Anaerobic culture

Fungal culture

Acid-fast bacilli

This is particularly appropriate in:

Immunocompromised patients

Unusual travel or exposure histories

Chronic or atypical infections

Timing of Cultures

Whenever safely possible, cultures should be obtained:

Before antibiotic administration.

However, antibiotic therapy should not be dangerously delayed in a septic or unstable patient simply to obtain cultures.

Bone Biopsy

Percutaneous bone biopsy may provide material for:

Culture

and

Histologic examination.

Because the infection often involves metaphyseal cancellous bone, the lesion may be accessible with a:

Bone biopsy or marrow-type needle.

Young children commonly require sedation or anesthesia.

Localization Before Aspiration

If the infected site is uncertain, it may first be localized using:

MRI

or, less commonly,

Bone scintigraphy.

Imaging

Plain Radiographs

Radiographs should usually be obtained as an initial study.

The earliest finding may simply be:

Soft-tissue swelling.

Delayed Osseous Changes

Classic bony abnormalities often lag behind symptoms.

These may not become visible for approximately:

1–3 weeks.

Findings include:

Osteopenia

Bone resorption

Cortical destruction

Periosteal new bone formation

CT

CT is not usually the preferred test for diagnosing acute hematogenous osteomyelitis.

It may be useful for:

Chronic cortical abnormalities

Sequestra

Surgical planning

Differentiating certain osseous lesions

such as:

Osteoid osteoma

or

Chondroblastoma.

MRI

MRI is the most useful advanced imaging modality for most suspected osteomyelitis.

It provides excellent sensitivity for:

Early marrow involvement

Subperiosteal abscess

Soft-tissue extension

Adjacent joint infection

Anatomic extent of disease

MRI Sequences

T1-weighted images provide detailed anatomy and show marrow replacement as low signal.

Fluid-sensitive or T2-weighted fat-suppressed/STIR images demonstrate:

Marrow edema

Soft-tissue inflammation

Periosteal elevation

Fluid collections

Neonates

In neonates, broader scout or localizer imaging may help identify the involved region when localization is difficult clinically.

Ultrasound

Ultrasound may identify:

Subperiosteal fluid

Joint effusion

Superficial abscess

It is useful for guiding aspiration.

However, ultrasound cannot adequately assess:

Deep intramedullary metaphyseal infection.

Pathophysiology

Acute hematogenous osteomyelitis in children classically begins in the:

Metaphysis of a long bone.

Vascular Seeding

Bacteria lodge in the metaphyseal circulation, where:

Slow blood flow and vascular architecture

favor bacterial deposition.

Intraosseous Infection

As infection progresses:

Inflammatory cells accumulate

Medullary pressure rises

Small vessels may thrombose

This compromises local blood flow and may produce:

Bone necrosis.

Cortical Spread

Pus follows the path of least resistance and may extend through the:

Metaphyseal cortex.

Subperiosteal Abscess

Once infection exits the cortex, it may elevate the periosteum and form a:

Subperiosteal abscess.

Later, the elevated periosteum may produce:

Periosteal new bone formation.

Chronic Infection

If devascularized bone persists, it may become a:

Sequestrum, serving as a reservoir for chronic infection.

Reactive new bone around the infected segment may form an:

Involucrum.

Differential Diagnosis

Important alternatives include:

Trauma

Septic arthritis

Cellulitis

Ewing sarcoma

Leukemia

Thrombophlebitis

Sickle cell vaso-occlusive crisis

Transient synovitis

Eosinophilic granuloma

Osteoid osteoma

Septic Arthritis

Septic arthritis should be strongly considered when there is:

Severe pain with passive joint movement

Joint effusion

Marked restriction of motion

It may coexist with osteomyelitis, especially in infants.

Malignancy

Ewing sarcoma and leukemia may produce:

Pain

Fever

Elevated inflammatory markers

Abnormal imaging

and can closely mimic infection.

Biopsy may be necessary when the diagnosis remains uncertain.

Treatment

General Principles

Treatment is based on four major principles:

Identify the causative organism

Administer appropriate antimicrobial therapy

Drain or débride infection when necessary

Continue treatment until clinical and inflammatory markers indicate resolution

Early Disease

Surgery may not be necessary when:

The diagnosis is made early

There is no abscess

There is no necrotic bone

The patient responds promptly to antibiotics

Antibiotic Therapy

Antibiotics should initially be chosen empirically according to:

Patient age

Likely organism

Local resistance patterns

Recent hospitalization

Underlying disease

and then narrowed according to:

Culture and susceptibility results.

Empiric Therapy

Because Staphylococcus aureus is the most common pathogen, empiric treatment generally includes antistaphylococcal coverage.

Depending on local prevalence of MRSA, this may require:

An antistaphylococcal beta-lactam

or

MRSA-active therapy such as clindamycin or vancomycin.

Neonates

Neonates require broader coverage because infection may involve:

Staphylococcus aureus

Group B Streptococcus

Gram-negative organisms

The exact regimen should follow neonatal infectious-disease protocols and local susceptibility patterns.

Duration of Antibiotic Therapy

Treatment duration depends on:

Age

Organism

Clinical response

Presence of abscess

Complications

Route of infection

Many uncomplicated pediatric cases can transition from intravenous to oral therapy after:

Clear clinical improvement and falling inflammatory markers.

Total therapy is commonly measured in:

Several weeks, rather than by a rigid IV duration.

Transition to Oral Therapy

Oral therapy can be used when:

The child is clinically improving

CRP is falling

The organism and susceptibilities are known

An effective oral antibiotic with good bioavailability is available

Surgery

Surgery is required when medical treatment alone is unlikely to control the infection.

Indications for Surgery

Common indications include:

Frank pus or abscess

Substantial necrotic or devascularized bone

Failure to improve after approximately 36–48 hours of appropriate antibiotics

Progressive clinical deterioration

Need for diagnostic tissue when the diagnosis is uncertain

Surgical Technique

Operative treatment may include:

Opening and draining the subperiosteal space

Cortical drilling or creating a bone window

Evacuation of pus

Débridement of necrotic tissue

Removal of devascularized bone when present

Multiple deep cultures should be obtained during surgery.

Chronic Osteomyelitis

Chronic infection may require more extensive management, including:

Removal of sequestra

Repeated débridement

Dead-space management

Soft-tissue reconstruction

Long-term culture-directed antibiotics

Follow-Up

Patients should be monitored until there is:

Resolution of pain

Return of function

Normalization or near-normalization of inflammatory markers

No evidence of recurrent infection

Prognosis

Most children treated promptly and appropriately have an:

Excellent prognosis

with no major long-term sequelae.

Poor outcomes are more likely when:

Diagnosis is delayed

Abscess or necrotic bone persists

The growth plate is damaged

Chronic osteomyelitis develops

Complications

Chronic Osteomyelitis

Delayed or inadequate treatment may result in:

Persistent infection

Sequestrum formation

Draining sinus

Recurrent abscess

Growth-Plate Injury

If infection damages or crosses the physis, the child may develop:

Partial or complete growth arrest

leading to:

Angular deformity

or

Limb-length discrepancy.

Pathological Fracture

A severely weakened bone may fracture before sufficient:

Healing and remodeling

have occurred.

Activity should therefore be progressed cautiously when substantial structural bone loss is present.

Septic Arthritis

Spread into an adjacent joint may produce:

Septic arthritis, particularly in infants where metaphyseal blood vessels may cross the physis.

Systemic Complications

Severe osteomyelitis may be associated with:

Bacteremia

Sepsis

Venous thromboembolism

Disseminated intravascular coagulation

Systemic inflammatory response syndrome

Patient Monitoring

Monitoring should include:

Clinical pain and function

Temperature

Local swelling and tenderness

CRP

ESR when appropriate

Repeat imaging when recovery is atypical

CRP is particularly useful for following early treatment response because it changes more rapidly than ESR.

Key Principle

Osteomyelitis is a bone infection that requires early recognition, microbiologic diagnosis, appropriate antibiotic therapy, and surgical drainage or débridement when abscess or devitalized bone is present.

In children, the disease typically begins in the:

Metaphysis of a long bone, and prompt treatment usually results in complete recovery while minimizing the risk of:

Chronic infection, growth disturbance, pathological fracture, and systemic complications.

Orthopaedic Surgery - Osteoid Osteoma

Basics

Osteoid osteoma is a small, benign, bone-forming tumor that occurs predominantly in children, adolescents, and young adults.

Despite its small size, it can produce disproportionately severe pain.

The central tumor focus, known as the nidus, is usually:

Less than 1–1.5 cm in diameter.

Lesions significantly larger than this should raise consideration of another diagnosis, such as osteoblastoma.

Epidemiology

Osteoid osteoma is one of the most common benign bone-forming tumors.

Historically, it has accounted for approximately:

10–12% of benign bone tumors

and

About 3% of primary bone tumors.

Age

It occurs most commonly between approximately:

5 and 25 years of age.

A slight male predominance is typical.

Common Locations

More than half of lesions occur in the:

Metaphysis or diaphysis of long bones.

Frequently affected long bones include the:

Femur

Tibia

The tumor also has a recognized predilection for:

Spine

Pelvis and sacrum

Ribs

Small bones of the hands and feet

Risk Factors

There are no known environmental or lifestyle risk factors for osteoid osteoma.

Etiology

The cause is unknown.

It is not generally associated with:

Trauma

Hereditary syndromes

or

Systemic disease.

Pathophysiology

The nidus contains:

Osteoid tissue

Immature woven bone

Numerous osteoblasts

Highly vascular connective tissue

Prostaglandin Production

A distinctive feature of osteoid osteoma is production of high concentrations of:

Prostaglandins, mediated in part through cyclooxygenase pathways.

These substances produce:

Vasodilation

Local inflammation

Intense pain

This explains the dramatic response to:

Aspirin or other NSAIDs.

Reactive Bone Formation

The surrounding bone frequently responds to the nidus by producing:

Dense reactive sclerosis

Cortical thickening

Periosteal new bone

The amount of reactive bone varies according to the location of the lesion.

Associated Conditions

There are no specific systemic conditions consistently associated with osteoid osteoma.

However, the lesion can produce important secondary effects depending on its location.

Diagnosis

The diagnosis is based on:

Characteristic pain

Response to NSAIDs

and

Imaging findings, particularly thin-section CT.

Signs and Symptoms

The hallmark symptom is:

Persistent localized pain.

Pain can occur both:

At rest

and

With activity.

Nocturnal Pain

Pain is classically:

Worse at night.

Untreated patients may experience pain throughout the day as well.

Response to NSAIDs

One of the most characteristic historical features is:

Near-complete or dramatic relief of pain after aspirin or an NSAID.

This response strongly supports the diagnosis, although it is not completely specific.

Juxta-Articular Lesions

Lesions located near a joint may have an atypical presentation.

They can produce:

Joint pain

Effusion

Synovitis

Stiffness

Flexion contracture

These cases may initially be mistaken for inflammatory or intra-articular disease.

Spinal Osteoid Osteoma

A spinal lesion may cause:

Painful scoliosis

Paraspinal muscle spasm

Localized back pain

The curve is usually secondary to pain and muscle spasm rather than a primary structural scoliosis.

Growth Disturbance

When a lesion occurs near an open growth plate, it may occasionally cause:

Altered physeal growth

Limb-length discrepancy

Localized overgrowth or deformity

Physical Examination

The examination may be:

Completely normal.

Local Findings

Some patients demonstrate:

Localized tenderness

Muscle spasm

Restricted motion

Protective posture

Juxta-articular lesions may cause:

Joint stiffness or effusion.

Spinal Examination

Spinal lesions may produce:

A painful scoliosis

with:

Paraspinal spasm and limited spinal motion.

Imaging

Plain Radiographs

Radiographs may demonstrate the classic lesion:

A small radiolucent nidus surrounded by dense reactive sclerosis.

Additional Radiographic Findings

Other findings may include:

Cortical thickening

Periosteal reaction

Dense surrounding sclerosis

In some locations, especially:

Intra-articular or cancellous lesions, the surrounding sclerosis may be minimal and radiographs may appear nearly normal.

CT

Thin-section CT is usually the most useful diagnostic imaging study.

It typically demonstrates:

A small radiolucent nidus

surrounded by

Reactive sclerosis.

Central Mineralization

The nidus may contain:

Central mineralization or ossification.

This is a classic CT feature.

Role of CT

CT is particularly valuable for:

Identifying small cortical lesions

Defining the exact nidus location

Planning percutaneous ablation

It is generally superior to MRI for directly demonstrating the nidus.

MRI

MRI can demonstrate substantial surrounding inflammatory change but may not show the nidus as clearly as CT.

MRI Findings

Findings may include:

Bone marrow edema

Soft-tissue edema

Synovitis

Joint effusion

The degree of edema may be striking compared with the small size of the lesion.

MRI Pitfall

Extensive edema can obscure the nidus and lead to misdiagnosis as:

Osteomyelitis

Stress injury

Inflammatory arthritis

Aggressive tumor

Therefore, CT should be considered when osteoid osteoma remains clinically suspected despite nonspecific MRI findings.

Bone Scintigraphy

Bone scintigraphy typically demonstrates:

Marked focal increased radionuclide uptake.

A characteristic pattern may include intense central uptake surrounded by less intense activity.

A negative bone scan makes osteoid osteoma less likely.

Differential Diagnosis

Important differential diagnoses include:

Stress fracture

Subacute osteomyelitis

Osteoblastoma

Chondroblastoma in selected locations

Inflammatory or mechanical joint disease

Stress Fracture

A stress fracture may also produce:

Localized pain and reactive sclerosis.

CT or MRI can usually demonstrate the fracture line and distinguish it from a discrete nidus.

Osteomyelitis

Subacute osteomyelitis, particularly a Brodie abscess, may resemble osteoid osteoma radiographically.

Clinical history, inflammatory findings, and imaging morphology help differentiate the two.

Osteoblastoma

Osteoblastoma has histologic similarities to osteoid osteoma but is generally:

Larger

Less responsive to NSAIDs

and more likely to involve the:

Posterior elements of the spine.

Treatment

General Principles

Treatment is indicated when pain significantly interferes with:

Sleep

Activity

School or work

Daily function

The lesion is benign and may eventually resolve spontaneously.

Diagnostic Clue

Strong suspicion should arise when a young patient with focal bone pain reports:

Dramatic relief with aspirin or NSAIDs.

Activity

There are usually no mandatory activity restrictions.

The affected bone is generally not at high risk for:

Pathologic fracture.

Activity may nevertheless be limited temporarily by pain.

Nonoperative Treatment

Observation with NSAID therapy can be considered in selected patients because osteoid osteoma may eventually undergo:

Spontaneous involution or “burnout.”

NSAID Therapy

Long-term NSAID treatment may provide excellent symptom control.

However, prolonged therapy can cause adverse effects including:

Gastrointestinal irritation or bleeding

Renal dysfunction

Cardiovascular complications

and, with certain medications,

Hepatic toxicity.

For this reason, prolonged medical treatment is not appropriate for every patient.

Duration of Conservative Treatment

Historically, some patients have been treated with NSAIDs for:

Up to approximately 2 years

while awaiting spontaneous resolution.

The duration should be individualized according to:

Symptoms

Medication tolerance

Patient preference

Lesion location

Physical Therapy

Physical therapy generally has no role in treating the lesion itself.

It may occasionally help restore:

Motion or strength after prolonged pain or secondary joint stiffness.

Bracing

Bracing is generally not required.

Percutaneous Ablation

The standard contemporary treatment for symptomatic osteoid osteoma is:

Image-guided percutaneous ablation.

Radiofrequency Ablation

Radiofrequency ablation is one of the most established techniques.

Under CT guidance, a probe is inserted into the nidus and thermal energy is applied to destroy the tumor.

Temperatures are typically raised to approximately:

80–90°C for several minutes.

Protection of Adjacent Structures

Thermal ablation must be performed carefully when the lesion lies near:

Skin

Nerves

Spinal cord

Joint cartilage

Major blood vessels

Insulation, hydrodissection, temperature monitoring, or alternative techniques may be used to protect surrounding tissues.

Other Percutaneous Techniques

Other minimally invasive options may include:

Laser ablation

Cryoablation

Microwave ablation

depending on local expertise and lesion location.

Surgical Excision

Open surgery is now rarely necessary.

Options include:

Curettage

or

En bloc excision.

Indications for Open Surgery

Surgery may still be considered when:

Percutaneous access is unsafe

The diagnosis remains uncertain

The lesion lies near critical neurovascular structures

A spinal lesion requires direct decompression or stabilization

Prior ablation has failed

Small Bones and Spine

Some surgeons may favor direct surgical treatment for selected lesions involving:

Small bones of the hands or feet

or

Certain spinal locations

when precise ablation cannot be performed safely.

Follow-Up

After successful ablation, patients generally experience:

Rapid and dramatic reduction in pain.

Relief may occur within:

Hours to days.

Persistent Pain

If significant pain continues after treatment, consider:

Incomplete ablation

Residual nidus

Recurrence

or

An incorrect initial diagnosis.

Repeat Ablation

A second percutaneous ablation may be performed when:

Residual or recurrent osteoid osteoma is confirmed.

Prognosis

Osteoid osteoma is:

Completely benign and self-limited.

It does not metastasize or undergo malignant transformation.

Once the lesion is correctly identified and treated, the prognosis is:

Excellent.

Complications

Potential complications of thermal ablation include:

Skin burn or necrosis

Nerve injury

Damage to adjacent cartilage

Incomplete ablation

Recurrence

Skin Injury

Skin necrosis is most likely when the lesion lies very superficially and thermal energy reaches the skin.

Risk can be reduced by:

Appropriate probe positioning

Insulation

Cooling or protective techniques

Maintaining adequate distance from the skin

Patient Monitoring

Routine long-term follow-up is usually unnecessary when:

Pain resolves completely and function returns.

Further evaluation is appropriate if:

Pain persists

Pain returns

New symptoms develop

In these circumstances, repeat imaging may be required to determine whether:

A repeat ablation is needed or the original diagnosis should be reconsidered.

Key Principle

Osteoid osteoma is a small benign osteoblastic tumor characterized by severe, often nocturnal pain that responds dramatically to NSAIDs.

The most useful diagnostic study is typically:

Thin-section CT showing a small nidus surrounded by reactive sclerosis.

For symptomatic lesions, image-guided percutaneous ablation, particularly radiofrequency ablation, provides highly effective treatment with rapid pain relief.

Orthopaedic Surgery - Osteogenesis Imperfecta

Basics

Osteogenesis imperfecta (OI) is a group of inherited connective-tissue disorders characterized primarily by abnormal collagen formation and increased bone fragility.

Although fractures and skeletal deformity are the most prominent manifestations, OI can also affect:

Teeth

Sclerae

Hearing

Ligaments and joints

Skin and other connective tissues

Cardiopulmonary function

The clinical severity ranges from very mild disease with occasional fractures to lethal perinatal forms.

Classification

The traditional Sillence classification remains widely used clinically, although many additional molecular subtypes have now been identified.

Type I

Type I is the:

Mildest and one of the most common forms.

Fractures generally begin during childhood and tend to become less frequent toward adolescence and adulthood.

Patients often have:

Blue sclerae

Relatively mild bone deformity

Normal or near-normal stature

The older classification subdivided Type I into:

Type IA – without dentinogenesis imperfecta

Type IB – with dentinogenesis imperfecta

Type II

Type II is the:

Most severe form and is usually lethal in the perinatal period.

Affected infants may have:

Multiple intrauterine fractures

Severe skeletal deformity

Markedly poor mineralization

Small thoracic cage

Death commonly results from profound respiratory insufficiency.

Type III

Type III is the:

Most severe form compatible with prolonged survival.

Typical findings include:

Numerous fractures beginning before or shortly after birth

Severe progressive bowing of long bones

Marked short stature

Progressive spinal deformity

Severe osteopenia

Patients frequently require repeated orthopaedic procedures.

Type IV

Type IV produces:

Moderate disease severity.

Patients generally have greater fracture and deformity burden than those with Type I but less severe disease than Type III.

Type V

Type V is a moderately severe form associated with characteristic findings such as:

Hyperplastic callus formation

Radial head dislocation

Interosseous membrane ossification in some patients

Unlike many classic OI types, Type V does not result from a primary Type I collagen structural mutation.

Additional Types

Many additional forms of OI have been identified through molecular testing.

Some result from abnormalities in:

Collagen synthesis

Collagen processing

Bone mineralization

Osteoblast function

The modern molecular classification is therefore considerably broader than the original Sillence system.

Pediatric Considerations

Severe forms may be diagnosed:

Prenatally or at birth.

Types II and severe Type III may present with:

Intrauterine fractures

Marked bowing

Multiple fractures at delivery

Milder Types I and IV may not become apparent until:

Infancy or early childhood, when fractures occur after relatively minor trauma.

In many forms, fracture frequency tends to decrease after puberty.

Epidemiology

OI affects approximately:

1 in 10,000–20,000 people, depending on the population and diagnostic definition.

Risk Factors

The major risk factor is:

Genetic inheritance or a de novo pathogenic variant.

There are no established environmental risk factors that independently cause OI.

Genetics

OI is genetically heterogeneous.

The majority of classic cases result from pathogenic variants involving:

COL1A1

or

COL1A2

which encode the chains of Type I collagen.

Many classic Type I–IV cases follow an:

Autosomal-dominant pattern, frequently from a new mutation.

Some rarer forms are:

Autosomal recessive

or follow other inheritance patterns.

Type I Collagen

Type I collagen is the principal collagen of:

Bone

Tendon

Skin

Sclera

and other connective tissues.

It forms a:

Triple-helical structure.

Glycine appears at every third position in the collagen chain.

Substitution of glycine with another amino acid may disrupt proper helix formation and produce an abnormal collagen molecule.

Dominant-Negative Effect

Certain structural collagen mutations produce abnormal collagen chains that interfere with normal chains.

This can exert a:

Dominant-negative effect, leading to more severe disease.

Other mutations primarily reduce the amount of otherwise normal collagen and often produce milder phenotypes.

Etiology

The fundamental abnormality is impaired production, structure, processing, or mineralization of bone matrix.

The result is bone that is:

Fragile

Osteopenic

and susceptible to:

Fracture and progressive deformity.

Associated Conditions

OI may be associated with:

Dentinogenesis imperfecta

Blue sclerae

Hearing loss

Ligamentous laxity

Joint dislocation

Scoliosis

Basilar impression or invagination

Hernias

Cardiopulmonary abnormalities

Dentinogenesis Imperfecta

Abnormal dentin formation may cause teeth that are:

Translucent

Brown, gray, or opalescent

Fragile

Both primary and permanent teeth may be affected.

Joint Laxity

Abnormal connective tissue may produce:

Ligamentous laxity and hypermobile joints.

This can predispose to:

Joint instability

Dislocations

Ankle instability

Hernias

Connective-tissue weakness may contribute to:

Inguinal hernias

Umbilical hernias

Diaphragmatic hernias

Craniovertebral Abnormalities

Softening and deformation of the skull base may result in:

Platybasia

Basilar impression

or

Basilar invagination.

These conditions may compress the brainstem or upper cervical spinal cord.

Diagnosis

Diagnosis is based on:

Clinical findings

Fracture history

Family history

Radiographic features

and

Genetic testing.

Signs and Symptoms

Common manifestations include:

Recurrent fractures

Bone pain

Short stature

Bowing of long bones

Scoliosis

Back pain

Blue sclerae

Abnormal dentition

Hearing loss

Joint hypermobility

Fracture Pattern

A child with OI may sustain fractures after:

Minor trauma

or an injury mechanism that would not normally fracture healthy bone.

Fractures may occur repeatedly throughout childhood.

Blue Sclerae

The sclerae may appear blue because abnormal collagen makes them sufficiently thin for the underlying pigment to become visible.

This finding is particularly common in Type I OI.

Hearing Loss

Conductive or sensorineural hearing loss may develop, often later in life.

Conductive loss may result from abnormalities of the:

Middle-ear ossicles.

Craniofacial Features

Some patients have:

Relative macrocephaly

and

A triangular facial appearance.

Musculoskeletal Pain

Adults with OI have an increased prevalence of:

Chronic musculoskeletal pain

related to previous fractures, deformity, joint degeneration, and muscle fatigue.

Basilar Invagination Symptoms

Brainstem or upper cervical cord compression may produce:

Weakness

Spasticity

Poor coordination

Respiratory dysfunction

Swallowing difficulty

Voice change

Progressive contractures

These symptoms warrant urgent specialist evaluation.

Physical Examination

The diagnosis should be considered when there is:

An unusually high fracture frequency

or fractures occurring after:

Minimal trauma.

Helpful Clinical Findings

Findings supporting OI include:

Positive family history

Blue sclerae

Abnormal dentition

Ligamentous laxity

Short stature

Long-bone bowing

Scoliosis

Laboratory and Genetic Testing

Routine laboratory studies are generally not diagnostic.

Molecular Genetic Testing

Genetic analysis from blood is now a major diagnostic tool.

Testing may identify pathogenic variants involving:

COL1A1

COL1A2

or other genes associated with OI.

A negative result on a limited test does not completely exclude the diagnosis because of genetic heterogeneity.

Collagen Analysis

Historically, cultured dermal fibroblasts obtained from a skin biopsy were used to analyze:

Type I collagen synthesis and structure.

This is now required much less often because comprehensive genetic testing is widely available.

Imaging

Generalized Osteopenia

Radiographs frequently demonstrate:

Diffuse osteopenia.

Long Bones

Typical findings may include:

Thin cortices

Narrow gracile shafts

Long-bone bowing

Multiple old fractures

Recurrent acute fractures

Severe Deformity

Advanced disease may produce severely deformed long bones, including the classic:

“Crumpled” femur

appearance in severe cases.

Pelvis

Pelvic abnormalities may include:

Trefoil-shaped pelvis

and

Protrusio acetabuli.

Spine

Vertebral bodies may be:

Osteopenic

Compressed

Flattened

or

Biconcave.

Repeated compression fractures may contribute to:

Kyphosis

Scoliosis

Loss of trunk height

Skull

The skull may demonstrate multiple:

Wormian bones, which are accessory ossification centers within the cranial sutures.

These are characteristic but not specific for OI.

Metaphyseal Changes

In severe cases, metaphyses may show:

Cystic or irregular appearances.

Repeated bisphosphonate treatment may also produce transverse metaphyseal density lines.

Pathological Findings

Bone may demonstrate:

Thin cortices

Reduced trabecular volume

Disorganized woven bone

Abnormal or deficient lamellar bone

Soft-Tissue Collagen

Collagen within the:

Skin

and

Cornea

may have a looser or structurally abnormal arrangement.

Differential Diagnosis

Important differential diagnoses include:

Prematurity and very low birth weight

Primary hyperparathyroidism

Scurvy

Hypophosphatasia

Achondrogenesis

Chondroectodermal dysplasia

Juvenile osteoporosis

Rickets

Congenital infection

Leukemia or other malignancy

Nonaccidental injury

Nonaccidental Injury

Distinguishing OI from child abuse may occasionally be difficult.

Findings that raise concern for nonaccidental trauma include:

Multiple fractures of different ages

Posterior rib fractures

Classic metaphyseal lesions

Inconsistent history

These findings require careful multidisciplinary assessment and should not automatically be attributed to OI.

Features Supporting OI

Features favoring OI may include:

Positive family history

Generalized osteopenia

Blue sclerae

Dentinogenesis imperfecta

Characteristic long-bone deformity

A pathogenic genetic variant

However, neither OI nor abuse should be diagnosed or excluded based on a single feature.

Treatment

General Principles

Management depends heavily on:

OI subtype

Severity

Age

Fracture burden

Mobility

Degree of deformity

The objectives are to:

Reduce fractures

Preserve mobility

Correct significant deformity

Improve independence

Prevent secondary complications

Type I

Patients with Type I disease may have relatively little functional impairment and may require mainly:

Fracture care

Exercise

Bone-health management

Hearing and dental surveillance

Type II

Severe Type II disease is usually lethal around the perinatal period.

Management focuses on:

Supportive and family-centered care.

Types III and IV

Types III and IV frequently create the greatest long-term orthopaedic challenges because of:

Repeated fractures

Progressive bowing

Short stature

Scoliosis

Mobility limitations

Medical Treatments With Limited Benefit

Historical treatments such as:

Growth hormone

Calcium supplementation in patients without deficiency

and

Calcitonin

have not consistently corrected the underlying skeletal disorder.

Bisphosphonates

Bisphosphonates such as:

Pamidronate

and other agents may improve:

Bone mineral density

Vertebral morphology

Pain

and, in selected children,

Fracture burden and mobility.

They do not normalize the skeleton.

Benefits appear most established in children with moderate-to-severe OI.

Rehabilitation

Physical therapy should be involved early.

Goals include:

Muscle strengthening

Safe standing

Ambulation

Preservation of joint motion

Prevention of contractures

Promotion of independence

Mobility Planning

Rehabilitation should establish realistic goals.

Depending on disease severity, children may require:

Walking aids

Standing devices

Adaptive seating

Wheelchairs

The objective is maximal safe participation rather than avoidance of all physical activity.

Hydrotherapy

Aquatic therapy can allow:

Active movement with reduced fracture risk

and may improve:

Muscle strength and endurance.

Orthoses

Braces can be useful adjuncts.

They should generally be:

Lightweight

Well fitted

Total-contact when appropriate

and designed to avoid producing excessive focal stress.

Joint hinges may be incorporated when necessary.

Fracture Treatment

Most fractures can initially be managed nonoperatively.

OI fractures usually have:

Good intrinsic healing capacity, despite poor bone strength.

Immobilization

Prolonged heavy casting should be avoided whenever possible because it may worsen:

Osteopenia

Muscle weakness

Loss of mobility

Lightweight splints or casts are often preferred.

Alignment

Although fractures generally heal, substantial angular deformity may produce:

Progressive bowing

Mechanical dysfunction

Recurrent fracture

Therefore, alignment should be restored as well as reasonably possible.

Recurrent Fractures

Internal fixation may be indicated when there are:

Repeated fractures

Severe long-bone bowing

Difficulty maintaining alignment with casting

Loss of ambulatory potential

Fixation Principles

Intramedullary fixation is generally preferred to plates and screws because:

Screws have poor purchase in osteopenic bone

and

plates can create a stress riser at their ends.

A new fracture may occur adjacent to a rigid plate.

Olecranon Avulsion Fractures

Olecranon avulsion fractures are seen with increased frequency in children with OI compared with the general pediatric population.

Medication

Bisphosphonate therapy remains an important medical treatment for selected patients with moderate or severe OI.

More recent management may also include other bone-directed or molecular therapies in specialized centers, depending on age and disease type.

Surgery

Anaesthetic Considerations

Patients with OI require careful perioperative planning because of:

Fragile bones

Potential cervical spine abnormalities

Limited neck or jaw mobility

Dentinogenesis imperfecta

Chest-wall deformity and restrictive lung disease

Possible cardiac valvular disease

Gentle positioning and airway management are essential to avoid iatrogenic fracture.

OI itself is not considered a proven direct cause of malignant hyperthermia; anaesthetic planning should instead focus on the patient’s specific airway, cardiopulmonary, and skeletal risks.

Corrective Osteotomy

Corrective osteotomy may be performed for:

Severe long-bone bowing

Repeated fractures

Loss of mechanical alignment

In appropriate children, these procedures may begin during early childhood when deformity interferes substantially with function.

Intramedullary Rodding

Intramedullary rods are particularly useful in children who:

Have recurrent fractures

Have severe bowing

Have realistic standing or ambulatory potential

Telescoping Rods

Telescoping devices such as the:

Fassier–Duval rod

can lengthen as the child grows.

This decreases the need for repeated revision compared with fixed-length rods.

Timing of Rodding

There is no single universal age or fracture number that mandates intramedullary fixation.

The decision should balance:

Fracture frequency

Severity of deformity

Functional potential

against risks such as:

Infection

Implant migration

Pain

Need for revision

Scoliosis

Scoliosis in OI may be:

Progressive and difficult to control.

Bracing often has limited ability to stop progression because the ribs and vertebrae are osteopenic.

Spinal Surgery

Surgical fusion may be considered for:

Progressive significant curves

especially when deformity threatens:

Sitting balance

Pulmonary function

Mobility

Older recommendations sometimes used approximately 40° as a threshold for considering fusion, although modern decisions are individualized according to progression, age, bone quality, pulmonary function, and overall condition.

Spinal Instrumentation

Modern segmental instrumentation has improved options for correction, but surgery remains technically difficult because of:

Poor bone quality

Thin pedicles

Fragile vertebrae

Risk of fixation failure

Craniocervical Junction

The craniovertebral junction must also be monitored.

Progressive basilar invagination can compress:

The brainstem

or

Upper cervical spinal cord.

Basilar Invagination Surgery

Symptomatic or progressive neural compression may require:

Decompression

and

Craniovertebral stabilization.

Follow-Up

Because OI can affect multiple systems, patients are best managed through:

A multidisciplinary or specialized OI clinic.

Care may involve:

Orthopaedics

Genetics

Endocrinology or metabolic bone specialists

Physical therapy

Dentistry

Audiology

Pulmonology

Cardiology

Neurosurgery

Prognosis

Prognosis varies dramatically according to OI type.

Type II

Type II is generally:

Lethal in the perinatal period.

Type III

Type III is severe and often requires:

Multiple orthopaedic procedures

Mobility aids

Long-term management of spinal and limb deformity

Type IV

Type IV generally has:

Intermediate severity.

Type I

Type I is typically the mildest classic form.

Many patients remain independently ambulatory.

Fracture Frequency

Across many OI types, fracture frequency tends to decline:

Around or after puberty.

However, fractures may recur later in adulthood as bone density decreases.

Hearing Loss

In Type I disease, progressive hearing loss can become one of the most important long-term functional complications.

Complications

Potential complications include:

Recurrent fracture

Progressive long-bone deformity

Scoliosis and kyphosis

Protrusio acetabuli

Joint instability

Hearing loss

Dental abnormalities

Chronic pain

Pulmonary restriction

Basilar invagination

Platybasia and Basilar Invagination

Softening of the skull base may produce progressive cranial deformation.

Neurologic consequences can include:

Weakness

Spasticity

Coordination difficulty

Swallowing or respiratory dysfunction

Patient Monitoring

Scoliosis

Children should be examined regularly from an early age for:

Development and progression of scoliosis.

Monitoring should continue into adulthood when clinically indicated.

Long-Bone Deformity

Follow-up should assess:

Fracture frequency

Bowing

Alignment

Mobility

Implant position in patients with rods

Neurologic Monitoring

Patients should be monitored for signs of:

Brainstem or upper cervical cord compression, particularly when cranial base abnormalities are known.

Hearing and Dental Monitoring

Periodic:

Audiologic

and

Dental evaluation

is important because these complications may progress independently of skeletal symptoms.

Key Principle

Osteogenesis imperfecta is a heritable disorder of collagen and bone formation characterized by skeletal fragility and multisystem connective-tissue abnormalities.

Orthopaedic management focuses on:

Preventing and treating fractures, minimizing deformity, preserving mobility, using intramedullary fixation when necessary, monitoring scoliosis and the craniocervical junction, and coordinating lifelong multidisciplinary care.

Orthopaedic Surgery - Osteochondroma

Basics

An osteochondroma is a benign cartilage-capped bony projection arising from the surface of a bone.

A solitary osteochondroma is generally considered a benign developmental abnormality related to the growth plate rather than a true neoplasm.

Osteochondromas may occur as:

A solitary lesion

or as part of

Multiple hereditary exostoses (MHE), also called hereditary multiple osteochondromas.

MHE is an inherited genetic disorder characterized by the development of multiple osteochondromas.

Epidemiology

Osteochondroma is one of the most common benign bone tumors or tumor-like lesions encountered in orthopaedic practice.

It usually develops during:

Childhood or adolescence

and typically stops enlarging after skeletal maturity.

Risk Factors

There are no clearly established risk factors for developing a solitary osteochondroma.

Multiple Hereditary Exostoses

MHE follows an:

Autosomal-dominant inheritance pattern.

An affected parent therefore has approximately a:

50% chance of transmitting the pathogenic variant to each child.

Pathophysiology

Osteochondromas are believed to arise from growth-plate cartilage cells that become displaced beneath the periosteum.

Instead of contributing to normal longitudinal growth, these cells grow outward from the metaphysis.

The lesion therefore consists of:

Cortical bone

Medullary bone

and

A cartilage cap.

Continuity With the Parent Bone

A defining feature of an osteochondroma is continuity of:

The cortex

and

The medullary canal

with the underlying parent bone.

This feature is particularly important in distinguishing osteochondroma from other surface bone lesions.

Cartilage Cap

The surface of the lesion is covered by a cartilage cap.

In adults, the cartilage cap is usually thin, often only:

A few millimeters.

In skeletally immature children, the cap can normally be substantially thicker and may reach approximately:

2–2.5 cm during growth.

After skeletal maturity, a thick or enlarging cartilage cap raises concern for malignant transformation.

Etiology

Solitary Osteochondroma

There is no single known cause for an isolated osteochondroma.

It is thought to result from:

Abnormal displacement or development of growth-plate cartilage.

Multiple Hereditary Exostoses

MHE is caused most commonly by pathogenic variants involving the:

EXT1

or

EXT2

tumor-suppressor genes.

Older literature described an additional EXT3 locus, but most genetically confirmed cases are related to EXT1 or EXT2.

These genes are involved in:

Heparan sulfate synthesis and regulation of normal growth-plate development.

Associated Conditions

A solitary osteochondroma generally has no specific systemic associations.

Multiple lesions should raise suspicion for:

Multiple hereditary exostoses.

Diagnosis

Diagnosis is usually based on:

History

Physical examination

and

Characteristic radiographic findings.

Signs and Symptoms

Many osteochondromas are discovered incidentally.

The most common presentation is a:

Firm, painless mass near a joint or metaphysis.

Pain may develop if the lesion causes:

Mechanical irritation

Bursal inflammation

Tendon irritation

Fracture

Nerve compression

Vascular compression

or, rarely,

Malignant transformation.

Physical Examination

The typical finding is a:

Hard, fixed, immobile mass arising from bone.

The examiner should assess:

Size

Tenderness

Skin changes

Joint motion

Neurologic function

Distal vascular status

Mechanical Symptoms

A lesion near a tendon or joint may cause:

Snapping

Restricted range of motion

Local irritation

Pain with activity

Neurovascular Examination

Osteochondromas occasionally compress adjacent:

Peripheral nerves

or

Blood vessels.

Symptoms may include:

Numbness

Weakness

Vascular insufficiency

Pulsatile mass

or other local neurovascular abnormalities.

Imaging

Plain Radiographs

Radiographs are usually diagnostic.

Characteristic findings include:

A bony protuberance arising from the metaphysis

Continuity of the lesion cortex with the parent cortex

Continuity of the medullary canal with the parent bone

Metaphyseal widening or deformity in some cases

The lesion may be:

Sessile

or

Pedunculated.

Pedunculated Osteochondroma

A pedunculated lesion often projects away from the nearby:

Growth plate or joint.

CT

CT is not required for every lesion.

It can be useful when the osteochondroma is located in a complex anatomic region or when the relationship to surrounding structures is uncertain.

CT demonstrates:

Cortical continuity

Medullary continuity

Relationship to adjacent bone and soft tissues

MRI

MRI is also not routinely necessary for a straightforward asymptomatic lesion.

It is useful for evaluating:

Cartilage-cap thickness

Soft-tissue structures

Neurovascular relationships

Bursal formation

Possible malignant transformation

MRI clearly demonstrates continuity of the lesion with the medullary cavity.

Cartilage-Cap Assessment

In a skeletally mature patient, concern increases when the cartilage cap becomes:

Unusually thick

or

Progressively enlarged.

Pain or growth after skeletal maturity also warrants further evaluation.

Differential Diagnosis

Important alternative diagnoses include:

Parosteal osteosarcoma

Heterotopic ossification

Other surface bone lesions may occasionally resemble an osteochondroma.

Parosteal Osteosarcoma

Parosteal osteosarcoma is a low-grade malignant surface tumor.

Unlike an osteochondroma, it generally does not demonstrate the classic:

Continuous cortex and medullary cavity with the underlying bone.

Heterotopic Ossification

Heterotopic ossification develops within soft tissue rather than arising directly from the growth plate or medullary cavity.

Mature lesions may become heavily ossified but do not show the typical architecture of an osteochondroma.

Treatment

General Principles

Most asymptomatic osteochondromas require only:

Observation.

Surgery is unnecessary when the lesion is:

Painless

Stable

Not interfering with function

and

Not suspicious for malignant change.

Activity

Patients with uncomplicated osteochondromas generally may participate in:

Normal activities without restriction.

Restrictions may be needed temporarily if symptoms develop or after surgical excision.

Physical Therapy

Physical therapy usually has no specific role in the treatment of an isolated osteochondroma.

It may occasionally be useful if secondary stiffness or weakness develops after surgery.

Surgery

Simple excision is considered when the osteochondroma is symptomatic.

Indications for Excision

Possible indications include:

Persistent pain

Mechanical irritation

Restricted joint motion

Nerve compression

Vascular compression

Recurrent bursal irritation

Cosmetic or functional deformity

Suspicion for malignant transformation

Surgical Technique

The lesion is excised at its base with removal of the:

Cartilage cap