Patient-reported outcomes in total hip arthroplasty for patients with anatomically contoured femoral heads

Introduction: Iliopsoas tendinitis after total hip arthroplasty (THA) has become more prevalent with the increased use of large-diameter femoral heads impinging on native surrounding tissues. Anatomically contoured heads (ACH) are soft-tissue-friendly femoral heads created to minimise this issue. This retrospective study assesses iliopsoas tendinitis prevalence and re-operations in primary THAs with ACH, while determining the minimal clinically important difference (MCID) achievement and improvement with 5 patient-reported outcome measures (PROMs).

Methods: We conducted a retrospective analysis of 53 ACHs from January 2020 to July 2023. Patients who completed Hip Injury and Osteoarthritis Outcome Score-Physical Function Short Form (HOOS-PS), Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function Short Form 10a (PF SF-10a), PROMIS Global Health (GH)-Mental, or PROMIS GH-Physical, and pain score questionnaires were identified. PROM scores were collected preoperatively and at 3-month and 1-year postoperative intervals. Comparisons using chi-square and ANOVA tests were applied.

Results: The rates of achieving MCID and improvement within the first year were (69.2 vs. 76.9%) for PROMIS GH-Physical, (38.5 vs. 46.2%) for PROMIS GH-Mental, (71.4 vs. 92.9%) for HOOS-PS, (80.0 vs. 80.0%) for PROMIS PF SF-10a, and (74.0 vs. 91.7%) for pain scores. PROM scores at 3 months and 1 year significantly varied across all categories, except for PROMIS GH-Mental. No patients had iliopsoas tendinitis, dislocations, or re-operations.

Discussion: ACH implants may alleviate anterior hip pain, while maintaining comparable strength and bio-compatibility to conventional femoral heads. This study underscores the early safety and potential of ACH implants in reducing iliopsoas tendinitis and impingement.