Outcomes of intraoperative greater tuberosity fractures in reverse shoulder arthroplasty: a matched cohort study

Background: Although uncommon, intraoperative greater tuberosity fractures (IGTFs) can occur during reverse total shoulder arthroplasty (rTSA) and may undermine clinical results. Our purpose was to determine, for both primary and revision rTSA, the 1) incidence of IGTF, 2) surgical steps when IGTF most often occurred, 3) healing rate of IGTF (assessed radiographically), and 4) clinical results (range of motion [ROM], pain, satisfaction, and patient-reported outcome measures [PROMs]) in patients with and without IGTF. Methods: We used our institution's shoulder database to retrospectively identify patients who underwent primary rTSA (n = 1,177) or revision rTSA (n = 225) from 2004 to 2022 by the senior author (E.G.M.). We included patients with at least 1 year of follow-up (at which point fractures would be considered nonunion or healed). Operative notes were analyzed to determine at which step in the operation the IGTF occurred. All IGTFs were treated with transosseous suture fixation. Patients with IGTF were matched by age, sex, surgery indication, and primary or revision surgery in a 1:2 ratio to patients who underwent rTSA and did not experience IGTF. Using radiographs, we classified the tuberosity as healed, displaced, or resorbed. ROM, pain, satisfaction, and PROMs were compared from preoperative to postoperative in both groups, and the 2 groups were compared with each other. Results: The incidence of IGTF was 3.4% overall (47/1,402), 2.5% in primary rTSA (29/1,177), and 8.0% in revision rTSA (18/225). IGTF occurred most frequently during reduction or dislocation of the humeral tray and polyethylene component during primary rTSA (n = 11/23, 48%) and during humeral component removal during revision rTSA (n = 12/16, 75%). At 1 year postoperatively, 22 of 36 IGTFs remaining for analysis had healed (61%), 6 (17%) were displaced, and in 7 (19%) the greater tuberosity fragments had been resorbed. When comparing the 39 primary and revision rTSAs eligible for evaluation with 78 matched controls, we found no differences between the 2 groups in the improvement from preoperative to most recent postoperative visit for ROM, pain, satisfaction, and PROMs. Conclusion: IGTFs are infrequent during primary rTSA, but the incidence is more than double when revising an arthroplasty to rTSA. When treated with repair at the time of surgery, most primary and revision cases with an IGTF had clinical results similar to those of a matched group of patients who did not sustain an IGTF during rTSA at minimum 1-year follow-up.