No migration of acetabular cups after prophylaxis for heterotopic ossification.

The possibility of migration of cementless cups in total joints after prophylaxis of heterotopic ossification with irradiation or nonsteroidal antiinflammatory drugs is a concern. Data investigating component stability with digital methods are lacking. This prospective study analyzed the migration of cementless cups after indomethacin and irradiation prophylaxis with the digital Einzel-Bild-Röntgen-Analyse tool. The irradiation group (106 hips) and the indomethacin group (98 hips) were compared with 82 hips that did not receive any prophylaxis. The same cementless acetabular implants were used in all cases, and patients were observed clinically and radiographically at 2 and 5 years. At the 5-year followup, the number of cups that showed migration greater than 1 mm in the irradiation group (five), the indomethacin group (three), and the control group (four) were not different. No cup was considered loose on the radiographs and no patient underwent revision surgery. The results of our study indicate irradiation or short-course use of indomethacin for prophylaxis of heterotopic ossification did not negatively affect the stability of cementless cups in primary total hip arthroplasties.