The purpose of this study was to report the clinical outcome of arthroscopic treatment for partial-thickness rotator cuff tear. We performed arthroscopic subacromial decompression (ASD) and rotator cuff repair (ARCR) for partial-thickness rotator cuff tear. In this study, a consecutive series of 39 patients with partial-thickness rotator cuff tear, who underwent ASD with ARCR and followed up for more than 6 months, were included. The average age was 61.6 years old (range, 45 to 75 years old), and mean follow-up period was 9.1 months (range, 6 to 24 months). The cases consisted of 20 males and 19 females, 28 right side and 11 left side, 25 BST cases and 14 AST cases. Clinical results were evaluated with the shoulder evaluation sheet of the Japanese Orhopaedic Association (JOA score). 28 of the 39 patients underwent Magnetic Resonance Imaging (MRI) on post operative months from 3 to 6, were classified according to Sugaya's Classification. At the final follow-up, the mean JOA scores was significantly improved from 68.2 (range, 50 to 82) to 89.6 (range, 71 to 100, P<0.01) of BST cases, and from 67.9 (range, 54 to 82) to 90.0 (range, 82 to 98, P<0.01) of AST cases. Postoperative MRI scans were classified into 20 cases type I, 7 cases type II, and 1 case type IV. The mean JOA score of type I was 93.4 (range, 85 to 100), and of type II was 78.7 (range, 71 to 86), and of type IV was 93.0. The group of Type II was worse result than other groups. The clinical outcome of our arthroscopic surgery was good, so combination of ASD and ARCR is one of the important option for treatment of partial-thickness rotator cuff tear.
