Selective COX-2 Inhibitors Significantly Reduce the Occurrence of Heterotopic Ossification After Hip Arthroscopic Surgery

Background: Heterotopic ossification (HO) after hip arthroscopic surgery is a common complication and may be associated with clinical sequelae such as pain, impingement, and decreased range of motion. Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used medications for reducing or preventing HO.

Hypothesis/purpose: The purpose of this study was to evaluate the effectiveness of short-term selective cyclooxygenase-2 (COX-2) inhibitors used for HO prophylaxis after hip arthroscopic surgery. The hypothesis was that postoperative HO prophylaxis with 600 mg etodolac once daily for 2 weeks would significantly reduce the incidence of HO after hip arthroscopic surgery when compared with no prophylaxis.

Study design: Cohort study; Level of evidence, 3.

Methods: Between July 2010 and April 2014, a total of 263 consecutive patients underwent hip arthroscopic surgery, performed by a single surgeon, for various pathological abnormalities at 1 medical center. The initial 163 patients received no postoperative NSAID prophylaxis for HO, and the subsequent 100 patients received 600 mg etodolac once daily for 2 weeks postoperatively. Prophylaxis compliance data, gastrointestinal side effects, and postoperative radiographs for HO were monitored.

Results: A total of 100 control patients and 63 study patients met the inclusion criteria. The mean follow-up period was 12.88 months. No significant differences were observed in terms of age, sex, follow-up, or procedures performed. No gastrointestinal bleeding was observed. Radiographic findings of HO were present in 36 of 100 control patients with 17, 15, and 4 classified as having Brooker grades 1, 2, and 3, respectively. No patients in the study group presented with HO, and a significant difference in the HO rate between groups was observed (P < .0001).

Conclusion: HO after hip arthroscopic surgery is a relatively common complication, with a rate of 19% for Brooker grade ≥2 in the patients who did not receive NSAID prophylaxis. No HO was found in the patients who received short-term COX-2 inhibitor prophylaxis. The short-term administration of 600 mg etodolac once daily for 2 weeks was found to be safe and effective in preventing HO in patients undergoing hip arthroscopic surgery. HO prophylaxis protocols based on short-term etodolac treatment may be considered after hip arthroscopic surgery.