Acute revision hip arthroplasty: a previously unrecognized risk factor for heterotopic ossification.

BACKGROUND

The aim of this retrospective review was to determine the incidence and severity of heterotrophic ossification (HO) following acute revision total hip arthroplasty (THA), and whether this represents a significant risk factor for HO that should be treated prophylactically.

MATERIALS AND METHODS

A total of seven patients (three men and four women) with a mean age of 55 years (39-70 years) who underwent a reoperation of their THA for any reason that required a hip arthrotomy within 3 weeks of their primary or revision THA were included, with a mean follow-up of 8.8 years (2-12 years). All patients were evaluated radiographically for any evidence of HO and clinically using the Harris Hip Score.

RESULTS

All seven hips (100 %) developed HO, with 71 % being severe (Brooker III and IV HO). One hip (14 %) developed Brooker IV HO, four hips (57 %) developed Brooker III HO, and two hips (29 %) developed Brooker II HO. The patient's range of motion varied, but was very limited in three patients. Three patients (42.8 %) were not satisfied with their surgery; one patient had Brooker IV HO, and two patients had Brooker III HO.

CONCLUSION

Acute reoperation after primary or revision THA is a significant risk factor for the development of extensive HO, which requires prophylactic treatment.