Osteochondritis Dissecans of the Capitellum

Introduction

Osteochondritis dissecans (OCD) of the capitellum is a condition affecting the:

• Articular cartilage
• Subchondral bone

of the capitellum in the elbow.

It is most commonly seen in:

• Adolescent throwing athletes

particularly those involved in repetitive overhead sports.

Early diagnosis is important because delayed treatment may lead to:

• Loose bodies
• Persistent pain
• Elbow stiffness
• Degenerative changes

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Epidemiology

Commonly Affected Population

OCD of the capitellum is frequently seen in:

• Adolescent baseball players
• Overhead throwing athletes
• Gymnasts

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Prevalence

The prevalence is estimated at approximately:

• 1–3% in adolescent baseball players

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Risk Factors

Important risk factors include:

• Early sports specialization
• Repetitive throwing
• High training volume
• Repetitive valgus loading of the elbow

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Biomechanics

Throwing Mechanics

The injury typically develops during the:

• Late cocking phase
• Acceleration phase

of throwing.

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Pathomechanics

These phases generate:

• Compressive forces
• Shear stress

across the radiocapitellar joint.

Repetitive loading may result in:

• Subchondral injury
• Cartilage damage
• Vascular compromise

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Pathophysiology

Early Stage

Initial changes include:

• Separation of cartilage from underlying bone

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Progressive Disease

Progression leads to:

• Delayed ossification
• Subchondral bone changes
• Fragment instability

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Advanced Disease

Advanced lesions may develop:

• Osteonecrosis
• Loose body formation
• Articular collapse

These changes increase the risk of long-term degenerative arthritis.

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Clinical Presentation

Symptoms

Patients commonly present with:

• Lateral elbow pain
• Reduced athletic performance
• Mechanical symptoms

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Mechanical Symptoms

Advanced lesions may cause:

• Catching
• Locking
• Clicking

due to unstable fragments or loose bodies.

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Physical Examination

Findings may include:

• Tenderness over the radiocapitellar joint
• Reduced range of motion
• Loss of extension
• Pain with valgus loading

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Imaging

Plain Radiographs

Standard radiographs may demonstrate:

• Capitellar flattening
• Subchondral lucency
• Fragmentation
• Loose bodies

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Important View

A:

• 45° flexion AP view

is particularly useful for identifying capitellar lesions.

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MRI

MRI is valuable for assessing:

• Lesion stability
• Cartilage integrity
• Subchondral bone viability

MRI also helps guide treatment decisions.

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Classification

Lesions are broadly categorized as:

• Stable
• Unstable

This distinction strongly influences management.

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Conservative Management

Indications

Non-operative treatment is appropriate for:

• Early-stage lesions
• Stable lesions
• Patients with open physes

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Treatment Components

Conservative treatment includes:

• Activity restriction
• Cessation of throwing
• Physiotherapy
• Gradual return to sport

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Duration

Rest from aggravating activity is typically recommended for:

• Approximately 3–6 months

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Surgical Management

Indications

Surgery is indicated for:

• Unstable lesions
• Loose bodies
• Persistent symptoms
• Failed conservative treatment
• Advanced OCD lesions

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Arthroscopic Debridement

Arthroscopic procedures may include:

• Debridement
• Loose body removal
• Microfracture

These procedures help improve symptoms and motion.

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Osteochondral Autograft Transplantation

Indications

Used for:

• Larger lesions
• Significant articular defects

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Principle

Healthy osteochondral grafts are transferred to restore:

• Articular congruity
• Joint surface integrity

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Outcomes

Prognosis

Outcomes are generally favorable with appropriate treatment.

Studies report:

• More than 90% good outcomes

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Return to Sports

Most athletes can successfully:

• Return to sport
• Resume throwing activities

especially with early diagnosis and treatment.

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Complications

Potential complications include:

• Persistent pain
• Elbow stiffness
• Loose bodies
• Degenerative arthritis
• Incomplete return to sport

Delayed diagnosis increases complication risk.

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Prevention

Preventive strategies include:

• Limiting excessive throwing
• Avoiding year-round overhead sports
• Proper pitching mechanics
• Adequate rest periods

Early recognition of symptoms is essential.

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Key Clinical Pearls

• OCD of the capitellum commonly affects adolescent throwing athletes.
• Repetitive valgus and compressive forces contribute to injury.
• Lateral elbow pain in young athletes should raise suspicion.
• The 45° flexion AP radiograph is particularly useful.
• MRI is important for assessing lesion stability.
• Stable lesions may heal with rest and activity modification.
• Unstable or advanced lesions usually require surgery.
• Early diagnosis improves outcomes and return-to-sport rates.

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Final Take-Home Message

Osteochondritis dissecans of the capitellum is an important cause of lateral elbow pain in young throwing athletes.

The condition results from repetitive radiocapitellar stress leading to:

• Cartilage injury
• Subchondral bone damage

Early identification and appropriate management are essential to prevent progression and preserve long-term elbow function.

Stable lesions often respond well to conservative treatment, whereas unstable or advanced lesions generally require surgical intervention.