Arthroscopic Finding of an Extra-Articular Loose Body in the Subacromial Space: Case Report Presentation and Literature Review.

Loose bodies are pieces of soft tissue that run free within a body cavity, typically in the synovium; loose bodies outside of synovial cavities are very rare. This case study demonstrates such an instance occurring in the subacromial space, which is especially unusual. We report on it coupled with an analysis of the literature of known cases that have occurred previously. A 55-year old right-hand-dominant female patient presented with left shoulder pain. She had injured her left shoulder 7 yr previously and had achieved adequate pain and symptomatic control with physiotherapy. A magnetic resonance imaging scan demonstrated subacromial subdeltoid bursitis with a large subacromial spur, a bulky acromioclavicular (AC) joint, and a partial tear of the supraspinatous tendon. The patient subsequently underwent shoulder arthroscopy for subacromial decompression and AC joint excision. Arthroscopy demonstrated a suspected impingement of the rotator cuff in the subacromial space, bursitis, and a prominent acromion that limited the subacromial space (bigliani, type III), but during the procedure a detached white mass was discovered in the subacromial bursa. After histological analysis, the mass showed osteocartilagenous tissue, consistent with a loose body. Following the procedure, there were no complications, and the patient's symptoms gradually resolved. Extraarticular loose bodies are extremely rare, especially in the subacromial bursa. Reported cases have all been associated with either traumatic or degenerative shoulder pathology, and the diagnosis was commonly established incidentally on arthroscopy. Cases were managed with removal during the same procedure. Arthroscopic removal of loose bodies and bursa debridement, good options for treatment of loose bodies in the subacromial space, can result in good function.