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

Introduction Pigmented villonodular synovitis(PVNS) is a rare condition affecting approximately 1.8 cases per 1 million persons. The shoulder is involved in about 2% of cases. Aim To present the largest series of patients with shoulder PVNS, massive irreparable rotator cuff tear and gleno-humeral(G-O)osteoarthritis treated with arthroscopic debridement and synovectomy. Methods We treated 9 patients with PVNS of the shoulder,irreparable rotator cuff tear and slight G-O arthropathy(group I) with arthroscopic synovectomy and debridement. Results were compared to those obtained from 33 patients(group II) undergoing arthroscopic debridement for irreparable cuff tear and having no(23 patients)or slight(10 patients)G-O arthropathy. Shoulder function was evaluated with Constant Score(CS). Results Preoperative shoulder function in group I was lower than group II(CS: 12 vs. 35). Upon follow-up, CS was lower in group I than in group II(CS: 40 vs. 54);the mean CS increase in the 9 PVNS patients(+28 points) was higher than other group(+14 points). Pre-operatively, differences were always statistically significant; instead, upon follow-up, significant differences emerged in CS,ADL and ROM. Differences relative to pre-operative CS in group I and II were statistically significant; while,at the follow-up, significant differences emerged only between CS of patients with PVNS and of group II without G-O arthropathy. Conclusion PVNS patients have a worse postoperative outcome respect to irreparable cuff tear patients with/without G-O arhtropathy. No differences emerged between final outcome of PVNS patients and that of patients with irreparable tear with G-O arthropathy. This suggest that arthroscopic synovectomy is an effective treatment for PVNS and that the poor outcome can be attributed to G-O arthropathy.