Abstract
BACKGROUND: Latissimus dorsi transfers have been considered necessary to restore active external rotation following reverse shoulder arthroplasty (RSA). The purpose of this study was to assess the effectiveness of an RSA system that lateralizes the center of rotation in restoring active external rotation without a latissimus dorsi transfer in patients with a preoperative external rotation deficit (external rotation of <0°). METHODS: We retrospectively reviewed the records of patients who had undergone RSA with a lateralized center of rotation without a latissimus dorsi transfer. All patients had had a preoperative external rotation deficit (active external rotation of <0°), and all were followed for a minimum of 2 years. Patients were stratified into 2 groups on the basis of the preoperative diagnosis: (1) those with a combined loss of active elevation and external rotation as a result of rotator cuff tear arthropathy (CLEER group) and (2) those with a combined loss of active elevation and external rotation as a result of other posttraumatic etiologies (non-CLEER group). The mean improvement of external rotation was analyzed. Subgroup analysis was performed on the basis of the Goutallier classification, glenosphere lateralization, and total prosthetic lateralization. RESULTS: Thirty-three patients (24 in the CLEER group and 9 in the non-CLEER group) met the inclusion criteria. The average follow-up was 43.4 months (range, 24 to 77 months). External rotation improved significantly in both the CLEER group (from -21° preoperatively to 28° postoperatively; p < 0.001) and the non-CLEER group (from -19° preoperatively to 26° postoperatively; p = 0.001). Goutallier classification, glenosphere lateralization, and total prosthetic lateralization were not correlated with the degree of improvement of external rotation in either group (p > 0.05 for all). CONCLUSIONS: RSA with a lateralized center of rotation can effectively restore external rotation without the use of a latissimus dorsi transfer in patients with a preoperative external rotation deficit as a result of rotator cuff arthropathy or other posttraumatic etiologies. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.