Legg-Calvé-Perthes Disease (LCPD)

Definition

Legg-Calvé-Perthes Disease is an idiopathic avascular necrosis (osteonecrosis) of the capital femoral epiphysis in children, characterized by a temporary loss of blood supply to the femoral head, resulting in bone death and eventual remodeling.

Epidemiology

• Demographics:
  • Peak age: 4-8 years
  • Male:Female ratio 4:1
  • Bilateral in 10-20% cases
  • More common in Caucasians
• Risk Factors:
  • Family history
  • Second-hand smoke exposure
  • Low socioeconomic status
  • Delayed skeletal maturation
• Associated Conditions:
  • Attention deficit disorder
  • Growth hormone deficiency
  • Coagulation abnormalities
  • Skeletal dysplasias

Pathophysiology & Staging

Disease Mechanism

• Vascular Events:
  • Interruption of blood supply
  • Multiple infarction episodes
  • Repetitive injury pattern
  • Revascularization process

Waldenstrom Classification (Radiographic Stages)

• Stage I (Initial):
  • Capital epiphyseal necrosis
  • Increased density
  • Maintained height
• Stage II (Fragmentation):
  • Subchondral fracture
  • Lateral subluxation
  • Head collapse
• Stage III (Reossification):
  • New bone formation
  • Healing pattern
  • Shape changes
• Stage IV (Remodeling):
  • Final shape established
  • Residual deformity
  • Growth completion

Clinical Features

Presenting Symptoms

• Primary Complaints:
  • Painless limp
  • Hip/knee/thigh pain
  • Limited range of motion
  • Morning stiffness
• Physical Findings:
  • Antalgic gait
  • Trendelenburg sign
  • Limited internal rotation
  • Thigh atrophy

Clinical Assessment

• Range of Motion:
  • Decreased abduction
  • Limited internal rotation
  • Fixed flexion deformity
  • Pain at extremes
• Gait Analysis:
  • Short stance phase
  • Trendelenburg gait
  • Compensatory mechanisms

Imaging & Classification

Radiographic Evaluation

• Standard Views:
  • AP pelvis
  • Frog-leg lateral
  • False profile view
  • Abduction/adduction views
• Key Findings:
  • Sclerosis
  • Fragmentation
  • Subchondral fracture
  • Head collapse

Classification Systems

• Catterall Classification:
  • Group I: <25% involvement
  • Group II: 25-50% involvement
  • Group III: 50-75% involvement
  • Group IV: Total head involvement
• Lateral Pillar (Herring) Classification:
  • Group A: No collapse
  • Group B: <50% collapse
  • Group C: >50% collapse

Advanced Imaging

• MRI:
  • Early diagnosis
  • Extent assessment
  • Containment evaluation
  • Prognostic value
• Bone Scan:
  • Early detection
  • Revascularization assessment
  • Disease progression

Treatment Approaches

Treatment Principles

• Goals:
  • Pain relief
  • Maintain motion
  • Prevent deformity
  • Preserve sphericity
• Containment Concept:
  • Maintain femoral head coverage
  • Prevent lateral subluxation
  • Guide remodeling

Conservative Management

• Physical Therapy:
  • Range of motion exercises
  • Muscle strengthening
  • Gait training
  • Activity modification
• Bracing:
  • Containment orthosis
  • Scottish Rite brace
  • Petrie cast

Surgical Interventions

• Containment Procedures:
  • Femoral osteotomy
  • Pelvic osteotomy
  • Combined procedures
  • Shelf acetabuloplasty
• Salvage Procedures:
  • Cheilectomy
  • Arthrodiastasis
  • Hip arthroscopy

Prognosis & Complications

Prognostic Factors

• Age-Related:
  • Better <6 years
  • Poor >8 years
  • Skeletal age impact
• Disease-Related:
  • Extent of involvement
  • Lateral pillar height
  • Containment status
  • Range of motion

Complications

• Early:
  • Joint stiffness
  • Muscle contractures
  • Leg length discrepancy
  • Pain persistence
• Late:
  • Early osteoarthritis
  • Femoral head deformity
  • Hip impingement
  • Need for total hip replacement

Follow-up Care

• Monitoring Schedule:
  • Regular radiographs
  • Range of motion checks
  • Activity modification
  • Long-term surveillance
• Patient Education:
  • Activity restrictions
  • Exercise program
  • Warning signs
  • Future implications