Pigmented villonodular synovitis of the shoulder associated with massive rotator cuff tear treated by arthroscopic synovectomy and debridement

Purpose: Pigmented villonodular synovitis (PVNS) is a rare condition. Our purpose is to describe the largest series of patients with shoulder PVNS, massive irreparable rotator cuff tear, and glenohumeral osteoarthritis treated with arthroscopic debridement and synovectomy. Methods: We treated 9 patients with PVNS of the shoulder, irreparable rotator cuff tear, and slight glenohumeral arthropathy (group I). Patients underwent arthroscopic synovectomy and debridement. Results [constant score (CS) and subjective shoulder value (SSV)] were compared to those obtained from a control group (group II) of 20 consecutive patients undergoing arthroscopic debridement for irreparable cuff tear associated with hemorrhagic synovitis with no or slight glenohumeral arthropathy. Histologic examination was obtained in all cases to obtain the correct diagnosis. Results: The preoperative shoulder function in group I was reduced with respect to group II. Upon follow-up, CS and SSV were lower in group I. Preoperatively, the differences relating to the CS value and to each item of the score were always statistically significant; instead, at follow-up, significant differences emerged in the CS, ADL, and ROM. At follow-up, significant differences emerged between CS of group I and of group II without glenohumeral arthropathy. Differences using the SSV were always statistically significant. Conclusions: The poor functional outcome of patients affected by PVNS can be attributed to the coexistence of the irreparable cuff tear and to the glenohumeral arthropathy. All patients with PVNS had shoulder osteoarthritis; it cannot be simply attributed to natural history of massive irreparable cuff tears, but to the pigmented villonodular synovitis.