Outcomes of cup revision for ilio-psoas impingement after total hip arthroplasty: Retrospective study of 46 patients

Abstract Background Impingement of the ilio-psoas tendon on the acetabular component is a cause of pain after total hip arthroplasty (THA). Studies of cup revision for ilio-psoas impingement (IPI) are scarce and limited in size. We therefore conducted a large multicentre retrospective study with the following objectives: to assess the effectiveness of cup replacement in resolving the impingement syndrome, to determine the frequency and nature of complications after cup revision for IPI, and to identify pre-operative factors associated with good outcomes of cup revision for IPI. Hypothesis Cup revision is effective in resolving the pain due to IPI in selected patients. Methods This retrospective multicentre study included 46 patients who underwent cup revision because of IPI. Before the revision, 38 (83%) patients had prominence of the anterior cup rim (mean, 9.9 ± 4.5 mm (range, 2–22 mm) by radiography and 35 (76%) had cup malposition (anteversion   50°). Mean follow-up was 21 months (range, 6 months to 6 years) and no patient was lost to follow-up. Outcomes at last follow-up were assessed based on the Oxford Hip Score (OHS), patient satisfaction index, complications, and revisions. Results At last follow-up, 39 (85%) patients were satisfied with the revision procedure, a significant improvement versus baseline was noted in the OHS (mean, 43 ± 6; range, 25–48; P P Discussion Cup revision for IPI after THA is effective in relieving the groin pain in 80% of patients with anterior cup rim prominence and/or cup malposition. However, complications can occur. Tenotomy may be preferable when the diagnosis is in doubt and/or cup position is acceptable. Level of evidence IV, retrospective observational study.