Outcomes of acute but not delayed reverse total shoulder arthroplasty for proximal humerus fracture are equal to those for rotator cuff arthropathy

Abstract

BackgroundThe utilization of reverse total shoulder arthroplasty (RTSA) for the treatment of proximal humerus fractures in the elderly is increasing. Recent results support the use of RTSA for this indication over hemiarthroplasty or open reduction internal fixation (ORIF). However, there are limited data on the outcomes of RTSA for fracture or fracture sequelae as compared to RTSA for cuff tear arthropathy (CTA). We hypothesized that patients undergoing RTSA for fracture or fracture sequelae would have worse outcomes compared to patients undergoing RTSA for CTA. MethodsThis was a retrospective analysis of a prospectively collected outcomes database of all patients undergoing shoulder arthroplasty at a single institution between 2008 and 2019. Patients were included if they underwent primary RTSA for a diagnosis of acute fracture, fracture nonunion or malunion, failed hemiarthroplasty or ORIF for proximal humerus fracture, or rotator cuff arthropathy. The primary outcome was American Shoulder and Elbow Surgeons (ASES) score at the most recent follow-up, with minimum 1-year follow-up. Secondary outcomes included range of motion (ROM) at most recent follow-up, patient satisfaction with surgery, and revision or reoperation rates. Analysis of variance was used to compare continuous variables between the groups, while chi-square or Fisher's exact test were used to compare categorical variables. Linear regression analysis was used to perform multivariable analysis. Prosthesis survival rates were calculated using Kaplan-Meier survival analysis. Significance was defined as P< .05. ResultsThere were 287 patients included in the final cohort, including 62 with fracture and 225 with CTA. Sex, diagnosis, increasing patient comorbidities, and diagnosis (malunion/nonunion and failed prior surgery) were associated with worse ASES scores on univariate analysis (P < .05). On multivariate analysis, there was no difference in outcomes (ASES and ROM) between the acute fracture and CTA cohorts (P > .05). Outcomes of delayed RTSA for malunion/nonunion and hemiarthroplasty/ORIF were significantly worse than those for acute fracture/CTA (P < .01). Three-year prosthesis survival was 95% for CTA, 97% for acute fracture, 97% for malunion/nonunion, and 78% for failed prior surgery. ConclusionTreatment of acute proximal humerus fractures with RTSA leads to similar improvements in patient outcomes compared to elective treatment for CTA, but outcomes of delayed RTSA for fracture are considerably worse. These findings provide further guidance to clinicians counselling patients on treatment options and outcomes for proximal humerus fractures. Level of evidenceLevel III; Retrospective comparative study