Coxa saltans caused by extraarticular synovial chondromatosis overlying an isolated osteochondroma of the greater trochanter: A rare aetiology.

Abstract

Snapping hip is produced by intraarticular and extraarticular pathology. We describe a rare case of extraarticular snapping hip caused by bursal synovial chondromatosis overlying an osteochondroma. A 32-year-old male presented with swelling in his right gluteal region for 6 years associated with pain and snapping on movements since three months. On examination, he had an ill-defined 10×6cm swelling over the posterolateral aspect of the greater trochanter. Plain radiographs revealed an osteochondroma arising from the greater trochanter. Further imaging showed exostosis with possible haemangioma, lipoma or liquefied haematoma overlying it. We proceeded with excision biopsy and intraoperatively found a bursa with synovial chondromatosis overlying the exostosis. At the end of ten months follow up, patient was asymptomatic and had no snapping. We present this case for its rarity, clinical and radiological diagnostic challenges and for its unique presentation.