Risk of Infection Following Reverse Shoulder Arthroplasty After Failed Rotator Cuff Repair: A Retrospective Review

Introduction Rotator cuff repair (RCR) is a treatment option for rotator cuff tear, but the failure rate is 11-57%, requiring reverse shoulder arthroplasty (RSA). Due to its success, indications for RSA have expanded to include patients who failed RCR without significant arthritis. Periprosthetic joint infection (PJI) rate after RSA (with prior RCR or not) is 2.4% and unexpected positive intra-operative cultures (UPIC) is 17%.. This study aims to identify infection rates in a historic cohort undergoing RSA who previously had an RCR. Material and Methods Medical records between 2015-2023 from one university hospital were screened for adult patients undergoing RSA for rotator cuff tear who have previously undergone ipsilateral RCR. Intraoperative samples were obtained in patients at high risk of PJI. PJI and UPIC rates were calculated and compared to the population norm using one-sample proportion test. Results During enrollment period, 92 patients (73.9 years, 42% male, 29.7kgm-2) met inclusion criteria and cultures were obtained from 23 high risk patients (72.1 years, 52% male, 31.1kgm-2). Two PJI were identified (80 y/o M and 83 y/o M), which corresponds to a PJI rate of 2.2%, which is not significantly different than the population norm. Of the remaining 21 cultures, 5 (23.8%) were UPIC of P. acnes, which was also not different. Minimal demographic or clinical differences were observed between those that had a negative culture and those that had UPIC. Discussion Our study found no increase in PJI or UPIC in patients undergoing RSA following ipsilateral RCR compared to previous reports on the general risk of infection for RSA alone. Although not the primary aim, the 23.8% incidence of UPIC in patients with suspected PJI is higher than the population norm of 17%. While this result was not statistically significant, it prompts discussion on developing guidelines for intraoperative culture sampling specific to patients with multiple ipsilateral shoulder surgeries. Level of Evidence: Level III- Retrospective Cohort Study