Heterotopic ossification after 2-incision total hip arthroplasty.

We examined the incidence of heterotopic ossification (HO) in a consecutive series of total hip arthroplasties (THAs) performed with the so-called minimally invasive, 2-incision technique. Standard preoperative hip radiographs were used to grade the extent of degenerative arthritis, and comparable follow-up radiographs at 30 months after surgery were used to detect and classify HO formation. Of 121 patients, 32 (26.5%) developed HO, with the Brooker class distribution as follows: stage I, 16 patients; stage II, 9 patients; stage III, 6 patients; stage IV, 1 patient. In this study, HO formation after 2-incision THA occurred with nearly the same frequency as that reported in other studies after standard THA.