Long-term results of partial repair for irreparable rotator cuff tear

Background: The irreparability of rotator cuff repair is generally determined during surgery. We have been performing partial repairs for rotator cuff tears that are deemed irreparable with primary repair. The aim of this study is to report, for the first time, the long-term postoperative outcome of our partial repair method and to clarify the criteria for the irreparability of primary repair. Methods: The UCLA score, radiographic findings, and magnetic resonance imaging findings of 156 shoulders that underwent rotator cuff repair (primary repair, 126 shoulders; partial repair, 30 shoulders) were retrospectively evaluated at preoperative and >10-year postoperative follow-up (mean evaluation time, 11.5 ± 1.0 years). Osteoarthritic (OA) changes were evaluated by radiographic findings, and the cuff integrity (Sugaya classification) and fatty infiltration (Goutallier classification) were evaluated by magnetic resonance imaging findings. These evaluations were compared between a primary repair group and partial repair group. Results: Although no significant difference was observed between preoperative and postoperative findings for the UCLA score, the strength of forward flexion was significantly lower at 10 years postoperatively in the partial repair group. Preoperative image evaluation showed no significant difference in OA changes between the 2 groups; however, fatty infiltration showed significantly greater progression in the partial repair group than the primary repair group. At >10-year postoperative follow-up, the OA changes, cuff integrity, and fatty infiltration showed significantly greater progression in the partial repair group compared to the primary repair group. Although the long-term outcome of the partial repair group was inferior to that of the primary repair group in imaging evaluations, good functional outcome of the shoulder joint was maintained. Conclusion: Our results suggested that partial repair could be an effective treatment option for irreparable rotator cuff tear. In terms of the feasibility of primary repair, the cutoff value for preoperative fatty infiltration was stage 2; thus, we believe that primary repair should be performed for cases with stage 2 fatty infiltration or lower, and partial repair should be performed for cases with stage 3 fatty infiltration or higher. However, manual workers and athletes with stage 3 fatty infiltration or higher should be advised in advance that mild muscle weakness may remain after surgery.