Revision to reverse total shoulder arthroplasty: do short stem and stemless implants reduce the operative burden compared to convertible stems?

Background Revision of prior hemiarthroplasty (HA) or total shoulder arthroplasty (TSA) to reverse shoulder arthroplasty (RSA) is a technically challenging procedure with high complication rates. The purpose of this study was to compare intraoperative complications between convertible humeral stems and nonconvertible humeral stems stratified by stem length for conversion of TSA or HA to RSA. Materials and methods A multicenter retrospective analysis of patients undergoing revision of a primary TSA or HA to RSA was conducted. Patients were divided into 2 groups based on convertible or nonconvertible humeral stem design from the index surgery. The primary outcome measures were the following intraoperative variables and complications: total operative time, blood loss, intraoperative fracture, overall complication rate, and blood transfusions. Rates were compared between groups and analyzed according to primary stem length for the nonconvertible group. Results A total of 279 patients were included in the study, 70 with convertible stems and 209 with nonconvertible stems. About 70% of convertible stems were successfully retained. Operative time was similar between the 2 groups overall. Patients with nonconvertible stems had higher intraoperative blood loss (P = .0001), higher overall complication rate (P = .009), and greater risk of intraoperative fracture (P = .002). Revising stemless and short stems to RSA had significantly reduced operative time compared to standard length stems (97 and 116 minutes vs. 141 minutes, P Conclusion In revision of anatomic TSA to RSA, convertible stems lead to lower blood loss and intraoperative fracture rate compared to nonconvertible stems when broadly including all stem types. However, differences appear to be based on stem type. Among nonconvertible stems, revision of short stem and stemless implants are associated with reduced operative time compared to standard length stems. Revision of stemless implants to RSA is associated with the shortest operative time of all implant types as well as a similar rate of intraoperative fracture compared to convertible stems. Level of Evidence Level III; Retrospective Cohort Comparative Study