Trochanteric heterotopic ossification after total hip arthroplasty performed using a direct lateral approach.

A unique pattern and location of symptomatic heterotopic ossification (HO) was observed in patients having total hip arthroplasty (THA) performed using a direct lateral approach, situated outside the hip capsule, distal, lateral, and anterior to the greater trochanter, designated as trochanteric heterotopic ossification (THO). Radiographs of 1420 consecutive primary total hip arthroplasties were reviewed. Three hundred and seventy hips (26%) developed HO around the hip and greater trochanter. One hundred of these hips (27%) demonstrated THO, without classic HO. Of the 270 cases containing a Brooker component, 110 hips exhibited additional HO (THO). Thus, THO occurred in 210 (14.8%) of 1420 THAs. Two patients required surgical excision of the HO after maturity, gaining full relief without recurrence. Trochanteric heterotopic ossification should be considered as a possible cause of early postoperative pain after THA performed using a direct lateral approach.