Osteitis deformans of the hip joint.

Area of Science:

• Orthopedics
• Rheumatology
• Pathology

Background:

• Paget's disease of bone (osteitis deformans) commonly affects the pelvis and proximal femur.
• Hip pain is a frequent symptom in patients with Paget's disease.

Observation:

• Radiographic analysis of 25 affected hips revealed joint space narrowing in 24.
• The radiographic pattern typically showed uniform articular cartilage narrowing with minimal hypertrophic changes, differing from primary degenerative joint disease.

Findings:

• Pathologic correlation from four hip replacements confirmed the radiographic findings.
• The study suggests cartilaginous narrowing arises from impaired endochondral bone formation due to hyperemia in Paget's disease.
• Secondary bone deformities contribute to joint derangement and altered mechanics.

Implications:

• The pathogenesis of arthritic changes in Paget's disease is linked to disturbances in bone formation and hyperemia.
• Radiographic and mechanical differences exist between Paget's disease-related arthritis and primary degenerative joint disease.
• Understanding these differences is crucial for accurate diagnosis and management of hip involvement in Paget's disease.