Definition
- Rare progressive loss of femoral head and acetabular cartilage
- Joint space narrowing, pain and stiffness
- Diagnosis of exclusion
Epidemiology
- Mostly adolescent girls around puberty
- Usually unilateral
- Higher rates reported in children of African and Asian descent
Aetiology
- Cause unknown
- Autoimmune mechanism proposed, with immune complexes and complement found in synovial fluid and synovium
- Secondary chondrolysis follows SCFE, septic arthritis, prolonged immobilisation or penetrating hardware
Clinical Features
- Insidious hip pain and limp
- Progressive global loss of motion
- Abduction contracture, often with flexion and external rotation contracture
- Pelvic obliquity and apparent leg length discrepancy
- Systemically well and afebrile
Investigations
- Radiographs show concentric joint space narrowing compared with the opposite hip, and periarticular osteopenia
- Later films show protrusio, femoral head flattening and lateral overgrowth
- FBC, inflammatory markers and autoimmune screen usually normal
- Aspiration excludes infection, with negative culture
- MRI shows cartilage thinning, synovial thickening, effusion and marrow oedema
- Bone scan shows increased uptake on both sides of the joint
Differential Diagnosis
- Septic arthritis, including tuberculosis
- Juvenile idiopathic arthritis
- Chondrolysis after SCFE
- Pigmented villonodular synovitis
- Osteoid osteoma and other tumours
- Perthes disease
Management
- Anti-inflammatory medication
- Physiotherapy to maintain and regain motion
- Protected weight bearing on crutches
- Traction or serial stretching for contracture
- Soft tissue release, capsulectomy or arthrodiastasis for resistant contracture
- Arthrodesis or THA as salvage for end-stage disease
Prognosis
- Variable outcome
- Some regain joint space and functional motion
- Others progress to fibrous ankylosis or secondary OA in early adult life
Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.