Impact of Postoperative Acetabular Wall Index on Patient-Reported Outcomes After Transposition Osteotomy of the Acetabulum in Patients With Hip Dysplasia.

INTRODUCTION: This study aimed to determine the effect of preoperative variables and three-dimensional acetabular correction on patient-reported outcome measures after transposition osteotomy of the acetabulum (TOA), a spherical periacetabular osteotomy. METHODS: We retrospectively reviewed 442 patients (582 hips) with hip dysplasia who underwent TOA between 1998 and 2019 and completed validated questionnaires, including the visual analog scale (VAS) for pain and satisfaction and the Hip disability and Osteoarthritis Outcome Score (HOOS). The median follow-up was 12 years. Associations between patient-reported outcome measures and preoperative variables and postoperative acetabular coverage (lateral center-edge angle, anterior wall index, and posterior wall index) were analyzed. RESULTS: Older age was negatively correlated with HOOS-ADL (r = -0.26, P < 0.001) and HOOS-sports/recreation (r = -0.25, P < 0.001). Male patients reported lower median HOOS-QOL than female patients (P = 0.038). Patients with Tönnis grade 0 had higher median satisfaction-VAS than those with grade 2 (P = 0.031), and higher median HOOS-ADL, sports/recreation, and QOL subscales than those with grade 1 or 2. For postoperative anterior wall index, the deficient group had higher VAS-pain (P = 0.045) and lower HOOS-pain (P = 0.047) than the normal group. For postoperative posterior wall index, the excessive group had lower HOOS-pain than the normal group (P = 0.029). CONCLUSION: Even in preserved hips after TOA, sagittal plane acetabular correction influenced postoperative pain, whereas age, sex, and Tönnis grade affected satisfaction, functional capacity, and QOL. These insights have implications for refining surgical indications and acetabular reorientation strategies, improving postoperative patient experience.