Postoperative changes in the tensor fascia lata muscle after using the modified anterolateral approach for total hip arthroplasty.

The modified Watson-Jones approach to the hip has been described as a minimally invasive approach with the potential for fewer postoperative complications than the traditional approach. Because the approach relies on an intermuscular rather than an internervous plane, there is potential for injury to the superior gluteal nerve. The aim of this study was to evaluate incidence of tensor fascia lata (TFL) denervation in patients undergoing this approach. Twenty-six patients underwent total hip arthroplasty (THA) using a modified anterolateral approach. Postoperative MRIs were analyzed for signs of muscle denervation including atrophy, hypertrophy and fat replacement. At a median follow-up of 9.3months, 74% of patients exhibited either atrophy or hypertrophy of the TFL and 42% exhibited fat replacement on MRI.