Anterior iliopsoas impingement after total hip arthroplasty.

Pain after total hip arthroplasty (THA) can be caused by a multitude of conditions, including infection, aseptic loosening, heterotopic ossification, and referred pain. It is also recognized that soft tissue inflammation about the hip, such as trochanteric bursitis, can lead to hip pain after THA. Two cases of persistent iliopsoas tendinitis following THA are reported, which are believed to be caused by psoas tendon impingement against a malpositioned, uncemented, metal-backed acetabular component. The authors are unaware of previous reports of this problem, and suggest that the problem be considered in the differential diagnosis of groin pain following THA.