Aspirin decreases the prevalence and severity of heterotopic ossification after 1-stage bilateral total hip arthroplasty for osteoarthrosis.

Heterotopic ossification (HO) is a frequent complication after total hip arthroplasty (THA). We retrospectively evaluated the prevalence and severity of HO in patients with osteoarthrosis who underwent 1-stage bilateral THA (OSBTHA) and compared those who received aspirin with those who received Coumadin for postoperative chemothromboprophylaxis. The aspirin group consisted of 66 patients (132 hips), with a mean age of 64 years (SD, 8.5). The Coumadin group consisted of 67 patients (134 hips), with a mean age of 60 years (SD, 10.2). Overall, HO was detected in 124 hips (46.6%). There were 43 hips (32.5%) with HO in the aspirin group and 81 (60.4%) in the Coumadin group (P < .00005). Aspirin significantly decreases the prevalence and severity of HO in comparison to Coumadin after OSBTHA.