REVERSE TOTAL SHOULDER ARTHROPLASTY FOR ACUTE PROXIMAL HUMERUS FRACTURES: IS DELAY ASSOCIATED WITH AN INCREASED RATE OF REOPERATION?

There has been a steady increase in the use of reverse total shoulder arthroplasty (RTSA) for the treatment of proximal humerus fracture (PHFs). There is now emerging evidence that performing a RTSA acutely may result in superior clinical outcomes when compared to secondary RTSA as a salvage procedure following failed management of a PHF. Studies have found acute RTSA to be associated with higher tuberosity healing rates, greater range of motion, and superior functional outcomes compared to treatment with secondary RTSA after initial management with internal fixation. However, there is a lack of consensus regarding optimal timing to perform an acute RTSA for PHF before the risk of complications and reoperation rise, with the current literature varying between 2 and 6 weeks post-fracture. A population-based cohort study was performed utilizing administrative healthcare data from Ontario, Canada. All adults aged 50 years and older in Ontario who sustained a PHF between April 1, 2004 and March 31, 2019 were identified. To ensure that none of the RTSAs in the delayed treatment were salvage procedures for other failed operative treatments, patients who underwent prior operative treatment before RTSA, including open reduction internal fixation (ORIF) and hemiarthroplasty, were excluded. Other exclusion criteria included polytrauma, open fractures, non-Ontario residents, and invalid or absence of provincial health insurance. Our primary objective was to identify the time interval between PHF and RTSA after which the risk of complication (and subsequent reoperation) significantly increased. A risk-adjusted, restricted cubic spline was used to model the probability of reoperation according to the time elapsed between PHF and RTSA. A secondary outcome measure was reoperation within two years following RTSA. A multivariate logistics regression was used to predict reoperation risk. A total of 914 patients (acute RTSA 687 patients, delayed RTSA 227 patients) underwent RTSA for PHF during the study period. The mean age was 72.5 y (range, 50–98 y) and the majority of patients were female (82.2%). The mean time from fracture to surgery was 45.7 days (range, 0–357 d). The acute RTSA cohort had significantly lower reoperation rates at 4.2% compared to the delayed RTSA cohort at 7.9% (p = 0.02). The odds of reoperation increased with a delay to RTSA greater than 28 days, at which point, the odds of reoperation continued to rise until it plateaued at 100 days post-fracture (Figure 1). In the multivariate analysis patients who underwent RTSA 28 days or more after PHF were found to have a higher odds of reoperation by 2 years (OR 1.85, 95% CI 0.98 to 3.47; P = 0.05) (Table 1). Among patients undergoing RTSA for acute PHFs, surgical delays of greater than 28 days were associated with a greater odds of reoperation by two years. In order to realize the reported benefits associated with acute RTSA in the fracture setting, a threshold of 28 days may be useful when counselling patients regarding reoperation risk and evaluating the risk-benefit profile during the shared decision-making process regarding treatment of acute PHFs. For any figures or tables, please contact the authors directly.