Reverse Total Shoulder Arthroplasty for Acute Proximal Humeral Fracture Has Comparable 10-Year Outcomes to Elective Indications: Results From the New Zealand Joint Registry.

HYPOTHESIS AND BACKGROUND: Recently, the indication of reverse total shoulder arthroplasty (RTSA) has expanded beyond rotator cuff arthropathy to include treatment of complex acute proximal humeral fracture (PHF). Limited previous studies have compared the long-term clinical and functional outcomes of patients undergoing RTSA for PHF versus elective indications for degenerative conditions. The purpose of this study was to compare implant survivorship, reasons for revision and functional outcomes in patients undergoing RTSA for acute PHF with those undergoing elective RTSA in a population-based cohort study.

METHODS: Prospectively collected data from the New Zealand Joint Registry from 1999 to 2021 and identified 6,862 patients who underwent RTSA. Patients were categorized by preoperative indication, including PHF (10.8%), rotator cuff arthropathy (RCA) (44.5%), osteoarthritis (OA) (34.1%), rheumatoid arthritis (RA) (5.5%) and old traumatic sequelae (5.1%). Revision-free implant survival and functional outcomes (Oxford Shoulder Score (OSS) at 6-months, 5- and 10-years follow-up) were adjusted by age, sex, American Society of Anesthesiologists (ASA) class and surgeon experience and compared.

RESULTS: Revision-free implant survival at 10 years for RTSA for PHF was 97.3%, compared to 96.1%, 93.7%, 92.8% and 91.3% for OA, RCA, RA and traumatic sequelae, respectively. When compared with RTSA for PHF, the adjusted risk of revision was significantly higher for traumatic sequelae (hazard ratio [HR] = 2.3; p = 0.023) but not for other elective indications. The most common reason for revision in the PHF group was dislocation/instability (42.9%), which was similar to the OA (47.6%) and traumatic sequelae (33.3%) groups. At 6 months post-surgery, OSS were significantly lower for the PHF group compared to RCA, OA and RA groups (31.1 vs. 35.6, 37.7, 36.5, respectively, p < 0.001), and similar to traumatic sequelae (31.7, p = 0.431). At 5 years, OSS were only significantly lower for PHF compared to OA (37.4 vs 41.0, p <0.001) and there was no difference between PHF and other groups. At 10 years, there were no significant differences between groups.

CONCLUSIONS: RTSA for PHF demonstrated reliable long-term survivorship and functional outcomes compared to elective indications. Despite lower functional outcomes in the early postoperative period for the PHF group, implant survivorship was similar in patients undergoing RTSA for the primary indication of acute PHF compared to RCA, OA and RA; and superior compared to the primary indication of traumatic sequelae.