Introduction

• Rare.
• Proliferative synovitis.
• Two forms: local and diffuse.
• Usually monoarticular; can involve synovia of bursae and tendon sheaths.
• Cause: unknown.
• Signs: swelling, pain, lameness.
• Diagnosis: synovial biopsy.
• Treatment: local excision +/- radiotherapy; excision arthroplasty if feasible (diffuse form).
• Prognosis: local - good following local excision; diffuse - poor following resection/good following excision arthroplasty.

Pathogenesis

Etiology

• Uncertain: ?neoplastic, immune-mediated, trauma or metabolic disturbance (lipid).

Pathophysiology

• Proliferative synovitis of uncertain etiology.

• Synovial proliferation → abnormal joint function → pain + lameness.

Diagnosis

Treatment

Outcomes