Extended Thromboprophylaxis With Rivaroxaban, Aspirin, or No Prophylaxis After Reverse Total Shoulder Arthroplasty: Practice Patterns and 90-Day Complications in a Single-Center Retrospective Cohort Study.

Background and objective Venous thromboembolism (VTE) after reverse total shoulder arthroplasty (RTSA) is uncommon but potentially fatal, and there is no consensus on extended pharmacological prophylaxis after discharge. This study described symptomatic VTE and other acute complications within 90 days of RTSA under the three extended prophylaxis strategies used in routine practice (rivaroxaban, aspirin, or no extended prophylaxis) and compared them descriptively. Methods We retrospectively reviewed all RTSAs performed by four shoulder and elbow surgeons at a single orthopedic referral center between January 2021 and April 2024. Patients with preoperative oral anticoagulation, follow-up shorter than three months, or a post-discharge regimen other than the three studied or not completed were excluded. All patients received intraoperative mechanical prophylaxis, enoxaparin 40 mg daily until discharge, and early mobilization. After discharge, in the absence of an institutional protocol, the treating surgeon chose rivaroxaban 10 mg once daily for 15 or 30 days, aspirin 81 mg once daily for 30 days, or no extended prophylaxis. Pulmonary embolism (PE) was confirmed by computed tomography pulmonary angiography. The primary outcome, symptomatic VTE, was compared with the exact Freeman-Halton test, Holm-adjusted pairwise Fisher's exact tests, and risk differences with Newcombe hybrid score 95% confidence intervals (CIs); other complications were described without inferential testing. Results Of 84 patients screened, 68 were included (52 women, 76.5%; median age 76 years, interquartile range 71-79), and all completed in-person follow-up at three months. No extended prophylaxis was given to 28 patients (41.2%), aspirin to 17 (25.0%), and rivaroxaban to 23 (33.8%). No symptomatic deep vein thrombosis occurred. Symptomatic PE occurred in one of 28 patients without extended prophylaxis (3.6%, 95% CI: 0.6-17.7; postoperative day 35, fatal), one of 17 receiving aspirin (5.9%, 95% CI: 1.0-27.0; day 22), and none of 23 receiving rivaroxaban (0%, 95% CI: 0-14.3) (p=0.717); no pairwise comparison approached significance after adjustment. Three non-thromboembolic complications occurred, all with rivaroxaban. Groups differed at baseline in age (p=0.019) and length of stay (p=0.019), and prophylaxis was almost entirely determined by the operating surgeon (p<0.001). Conclusions Because extended prophylaxis was chosen by the operating surgeon and was almost entirely collinear with surgeon identity, the observed differences cannot be attributed to the drugs themselves. No symptomatic PE occurred with rivaroxaban, but with only two events the estimates are highly imprecise and no comparison approached significance. These hypothesis-generating data describe institutional practice and do not establish the superiority of any strategy; extended thromboprophylaxis after RTSA should remain an individualized decision until adequately powered prospective studies are available.