A Study of Spinopelvic Relationship and its Impact on Functional Outcome of Total Hip Arthroplasty
Abstract
Abstract Introduction: Spinopelvic alignment plays a critical role in the biomechanics and functional outcomes of total hip arthroplasty (THA). This study evaluated changes in spinopelvic parameters following primary THA and their association with post-operative functional outcome. Materials and Methods: This prospective observational study included 80 patients undergoing primary THA at a tertiary care teaching hospital between April 2024 and June 2025. Demographic characteristics, spinopelvic parameters in standing, sitting, lateral decubitus, and lateral decubitus with 90° hip flexion positions, and Harris hip score (HHS) were assessed preoperatively and postoperatively. Functional outcomes were evaluated at 2 days, 14 days, 3 months, and 6 months after surgery. Correlations between spinopelvic parameters and HHS were analyzed using Pearson’s correlation coefficient. Results: The mean age of the patients was 48.33 ± 6.29 years, with males accounting for 60.0% of the study population. Significant post-operative improvements were observed in pelvic tilt (PT), sacral slope (SS), lumbar lordosis, and pelvic femoral angle (PFA) across different functional positions (all P < 0.05), whereas pelvic incidence (PI) remained unchanged (P = 0.87). Mean HHS improved significantly from 42.80 ± 6.50 preoperatively to 90.35 ± 4.75 at 6 months (P < 0.0001). PT demonstrated a significant negative correlation (r = −0.36, P = 0.010), while SS (r = 0.41, P = 0.003), PI (r = 0.39, P = 0.005), and PFA (r = 0.33, P = 0.018) showed significant positive correlations with functional outcome. All acetabular components were positioned within the Lewinnek safe zone. Conclusion: Primary THA significantly improved spinopelvic alignment and hip function. Several spinopelvic parameters were significantly associated with post-operative functional outcome, highlighting the importance of comprehensive spinopelvic assessment during pre-operative planning and post-operative evaluation.