ScholarWorks@중앙대학교

초록

Aims: This study aimed to evaluate the clinical outcomes and complication rates after reverse total shoulder arthroplasty (RTSA) with lateralized implant for patients with high-grade fatty infiltration (FI) of posterior rotator cuff including infraspinatus (ISP) and teres minor (TM). Methods: From January 2016 to June 2022, 139 patients who underwent primary RTSA with single lateralized implant with at least 2 years of follow-up were reviewed. According to FI of ISP from preoperative MRI, patients were divided into high ISP FI group (n = 88) and low ISP FI group (n = 51). Clinical outcomes and complications were compared between the two groups. A subgroup analysis was done with a high ISP FI group divided into low TM FI group (n = 77) and high TM FI group (n = 11). Results: At final follow-up, there was no significant difference in range of motion of forward elevation (P = 0.282), external rotation (ER; P = 0.467), and Constant score (P = 0.252) between the high ISP FI group and the low ISP FI group. At the final follow-up, patients in the high FI group demonstrated significantly reduced strength in both forward elevation (P = 0.049) and ER (P = 0.007) compared with those in the low FI group. However, the mean improvement in muscle strength from preoperative to postoperative evaluation in forward elevation and ER showed no significant difference between two groups (P = 0.559, 0.675, respectively). Subgroup analysis comparing low TM FI group and high TM FI group in the high ISP FI group showed that there were no notable differences in clinical outcomes between two groups. Bone mineral density, tear size in mediolateral dimension, ISP FI, and ER lag angle were found to be markedly associated with poor ER strength at final follow-up in univariate and multivariate analyses. Conclusion: Lateralized RTSA yielded marked improvements in shoulder motion, including forward elevation and ER, despite severe fatty changes in the ISP and TM. Level of Evidence: III, Retrospective case-control study.