Preoperative Posterior Pelvic Tilt Angle is Associated with Decreased Gait Speed and Hip Function in Older Patients with Hip Osteoarthritis

This study examined the relationships between preoperative posterior pelvic tilt with muscle strength, gait speed, hip function, and quality of life in older patients with hip osteoarthritis. This cross-sectional study included 65 patients with hip osteoarthritis (75.0 ± 10.4 years; 83.1% female). Pelvic tilt angle was calculated from the frontal view of the hip joint in the standing position using radiographic images. The patients were divided into anterior (n=13) and posterior (n=52) groups based on a standard pelvic tilt angle of 27.9°. Clinical outcomes included preoperative isometric hip flexion and knee extension muscle strength, a five-time sit-to-stand test, gait speed, the Harris Hip Score (HHS), and the Japanese Orthopedic Association Hip-Disease Evaluation Questionnaire score. Multiple regression analysis was performed to clarify the relationships between the posterior pelvic tilt and clinical outcomes. The posterior pelvic tilt group had significantly lower isometric knee extension muscle strength (P=0.032), HHS (P=0.020), and gait speed (P=0.006) than the anterior pelvic tilt group. Multiple regression analysis showed that the posterior pelvic tilt was significantly associated with lower gait speed (β=-0.271, P=0.046) and HHS (β=-0.272, P=0.045). Preoperative posterior pelvic tilt is associated with decreased gait speed and hip function in patients with hip osteoarthritis. Given that a posterior pelvic tilt may compromise stability during gait, restrict daily activities, and increase the risk of falls, physical therapy interventions targeting these factors are essential, even before total hip arthroplasty.