Effect of Corrective Spinal Alignment Surgery on Postoperative Range of Motion Following Reverse Total Shoulder Arthroplasty

Background Deterioration of sagittal spinal alignment (SSPA), particularly global kyphosis (GK), negatively impacts range of motion (ROM) after reverse total shoulder arthroplasty (rTSA). Therefore, this study aimed to investigate the clinical outcomes of rTSA performed after corrective spinal surgery, hypothesizing that this sequential approach would improve postoperative ROM. Methods We categorized 129 patients (followed > 2 years) into three groups: those without GK (n = 72), those with untreated GK (n = 42), and those who underwent prior corrective spinal surgery (n = 15). Postoperative ROM was compared among these cohorts. For the corrective spinal surgery group, we measured the C7-hip axis (C7-HA) distance, sagittal vertical axis (SVA), and lumbar lordosis (LL) before and after spinal intervention, but prior to rTSA. Results In the corrective spinal surgery group, significant improvements were observed in LL, C7-HA and SVA. The non-GK group demonstrated significantly greater flexion, abduction, and internal rotation than the other two groups, and significantly greater external rotation than the GK group; external rotation did not differ significantly from the corrective spinal surgery group. Following corrective spinal surgery, patients exhibited significant improvements in LL, C7-HA, and SVA achieving better postoperative C7-HA and SVA measurements than the untreated GK group. However, despite these partial alignment improvements, forward flexion and abduction in the corrective spinal surgery group were significantly lower at 24 months than those in the GK group Conclusion Prior corrective spinal alignment surgery was not associated with improved postoperative ROM after rTSA.