The Effect of Technological Innovations in Reverse Total Shoulder Arthroplasty on the Rate of Periprosthetic Acromion and Scapular Spine Fractures.

Abstract

Innovations in reverse total shoulder arthroplasty (rTSA) have improved outcomes and mitigated complications through improvements in implant design, surgical techniques, and enabling technologies. The purpose of this study was to evaluate the association between technologic evolutions in rTSA and the incidence of acromion and scapular spine fracture (ASF). The authors hypothesize that ASF incidence has decreased over time and that this decrease is temporally associated with successive changes in implant design, surgical technique, and enabling technology within a single-design platform. A retrospective case series from January 2007 to December 2024 was conducted. All patients undergoing rTSA by a single-implant manufacturer with a constant implant design philosophy (Enovis) were included. Patient-specific and surgical variables were collected. Five cohorts were formed based on major technologic advances focused on implant design, surgical technique, and virtual planning. Descriptive statistics were used to compare cohorts, while regression and moving average statistics assessed longitudinal trends. In total, 2,380 patients met inclusion criteria, including 2,068 primary rTSA and 312 revision rTSA cases. The overall incidence of ASF was 5.4% with no notable difference between primary and revision procedures. A higher incidence of ASF was observed for patients with rotator cuff deficiency when compared with rotator cuff-intact patients (7.39% vs. 2.8%; P < 0.001). A significant decrease in ASF incidence was observed across the study period (P < 0.001), with reductions between successive technologic cohorts. Regression analysis of the data revealed a logarithmic best-fit with r2 = 0.765. Year-to-year variability in ASF incidence was significantly lower during periods of routine preoperative planning compared with earlier periods (0.45% vs. 5.33%; P = 0.008). In 2014, the difference between the rates of cuff-intact and cuff-deficient cases disappeared (P = 0.025). Advancements in implant design and surgical technique within a single rTSA implant design philosophy were temporally associated with lower observed ASF incidence. Routine use of preoperative virtual planning coincided with the lowest ASF rates and reduced year-to-year variability. These findings should be interpreted in the context of time-related confounding, including surgeon experience and practice evolution. III.