3.P.41 SHOULDER SYNOVIAL CHONDROMATOSIS WITH COMBINED INTRA AND EXTRA-ARTICULAR INVOLVEMENT – A CASE REPORT.

Abstract

Primary synovial chondromatosis, defined by Jaffe (1951), is a rare, benign arthropathy, of unknown aetiology, distinguished by the chondroid metaplasia of the synovial membrane of the joint, bursa or tendon sheath, which leads to the formation of loose bodies, usually intra-articular. It is characteristically monoarticular and the knee, hip and elbow are the joints most commonly affected. The shoulder is a rare localisation and the extra-articular involvement even rarer, with only few cases presented in the literature.

The diagnosis is possibilited by the clinical examination and by the confirmation of the presence of multiple intra-articular loose bodies by roentgenographic studies and magnetic resonance (MR). The treatment is always surgical. Malignant degeneration of synovial chondromatosis into chondrosarcoma is described, although rare.

We report an exceptionally rare case of synovial osteochondromatosis of the shoulder with combined intra and extra-articular involvement in a 28 years old female patient, former athlete. She presented with a five-year history of shoulder pain and slight limitation of motion. Radiographic examination and magnetic resonance imaging led us to the diagnosis of synovial chondromatosis of the shoulder. The patient underwent arthroscopic removal of the intra-articular loose bodies and partial synovectomy. The subscapularis recess was then identified through an anterior deltopectoral incision and multiple loose bodies were removed from within.

Primary synovial chondromatosis of the shoulder is rare (5% of the cases) and the involvement of the extra-articular shoulder site is even rarer. Bloom and colleagues reported ten cases involving the shoulder in a meta-analysis of 191 synovial chondromatosis cases.

The arthroscopic removal of the loose bodies combined with the partial sinovectomy has demonstrated efficacy and low recurrence rates, allowing excellent visualization of the joint, decreased morbidity and early functional return. Nevertheless, we think that this approach may become insufficient when the extra-articular involvement is verified.