Juvenile Osteochondritis Dissecans (JOCD)
Juvenile Osteochondritis Dissecans (JOCD)
Key Points
- Focal separation of articular cartilage and subchondral bone
- Most common in adolescents aged 12-19 years
- Predominantly affects the knee (75% of cases)
- Better prognosis compared to adult OCD
- Early diagnosis crucial for optimal outcomes
Overview
Juvenile osteochondritis dissecans is a focal, idiopathic alteration of subchondral bone with risk for instability and disruption of adjacent articular cartilage that may result in premature osteoarthritis. It primarily affects the knee, particularly the lateral aspect of the medial femoral condyle, but can also occur in other joints.
Pathophysiology & Classification
Proposed Etiologies:
- Repetitive microtrauma
- Vascular insufficiency
- Genetic predisposition:
- Family history in 10-20% of cases
- Possible autosomal dominant inheritance
- Endocrine factors
- Ossification abnormalities
Common Locations:
- Knee (75%):
- Medial femoral condyle (70-80%)
- Lateral femoral condyle (15-20%)
- Patella (5-10%)
- Ankle (Talus)
- Elbow (Capitellum)
- Hip
Classification Systems:
- Berndt and Harty Classification (Radiographic):
- Stage I: Subchondral compression
- Stage II: Partial detachment
- Stage III: Complete detachment without displacement
- Stage IV: Complete detachment with displacement
- ROCK Classification (MRI):
- Grade A: Stable lesions
- Grade B: Progressive lesions
- Grade C: Terminal lesions
Clinical Presentation
History:
- Activity-related pain
- Mechanical symptoms:
- Catching
- Locking
- Giving way
- Risk Factors:
- Athletic participation
- Repetitive impact activities
- Family history
Physical Examination:
- Pain:
- Joint line tenderness
- Pain with compression
- Weight-bearing pain
- Range of Motion:
- May be limited
- Pain at extremes
- Crepitus
- Special Tests:
- Wilson test
- Extended knee flex test
Diagnosis & Assessment
Imaging Studies:
- Radiographs:
- AP, lateral, tunnel, and skyline views
- Contralateral comparison views
- Shows lesion size and location
- MRI:
- Gold standard for evaluation
- Assesses lesion stability
- Shows cartilage integrity
- Helps determine healing potential
- CT:
- Better bony detail
- Fragment size assessment
- Surgical planning
Differential Diagnosis:
- Osteochondral fracture
- Focal avascular necrosis
- Normal ossification variants
- Synovial disorders
- Meniscal pathology
Management
Treatment Decision Factors:
- Lesion stability
- Skeletal maturity
- Lesion size and location
- Symptom severity
- Activity level
Conservative Treatment:
- Activity modification:
- Protected weight-bearing
- Sport restriction
- Duration: 6-8 weeks minimum
- Physical therapy:
- Range of motion exercises
- Quadriceps strengthening
- Core strengthening
- Bracing or immobilization if needed
Surgical Management:
- Indications:
- Failed conservative treatment
- Unstable lesions
- Large lesions (>2cm²)
- Mechanical symptoms
- Surgical Options:
- Drilling:
- Retroarticular
- Transarticular
- Fragment fixation:
- Bioabsorbable pins
- Metal screws
- Advanced techniques:
- Microfracture
- Autologous chondrocyte implantation
- Osteochondral autograft/allograft
- Drilling:
Outcomes & Prevention
Prognostic Factors:
- Favorable:
- Young age
- Open growth plates
- Small, stable lesions
- Early diagnosis
- Poor:
- Large lesions
- Mechanical symptoms
- Closed growth plates
- Delayed treatment
Complications:
- Early osteoarthritis
- Persistent pain
- Limited function
- Loose body formation
- Failed fixation
Prevention Strategies:
- Activity modification
- Proper training techniques
- Regular screening in high-risk athletes
- Early recognition and treatment
