EFFECTS OF HIP FLEXION CONTRACTURE ON SAGITTAL SPINOPELVIC PARAMETERS

OBJECTIVE: To assess the influence of hip flexion contracture on lumbar lordosis and spinopelvic parameters and the changes in these parameters after total hip arthroplasty (THA). METHODS: Twenty adult patients with hip osteoarthritis were divided into two groups (ten patients with hip flexion contracture and ten without contracture). Patients were assessed preoperatively and six months after THA using the radiographic parameters sagittal vertical axis (SVA), lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS), and pelvic tilt (PT). RESULTS: No statistical difference was found between pre- and postoperative LL values in the groups. After THA, both groups had increased PT and the group without hip flexion contracture had reduced SS. CONCLUSION: Patients with hip osteoarthritis and hip flexion contracture tend to have an increased LL in the orthostatic position compared to patients without contracture, but with no statistical significance. After THA, PT increased in both groups and SS decreased in patients without hip contracture. Studies should further investigate the role of hip flexion contracture on pelvic mobility and spinopelvic parameters to better understand these relations. Level of Evidence III, Case-Control Study.