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

Objectives: 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.

Methods: 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.

Results: 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).

Conclusions: 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.