Variation in pelvic tilt during postural changes may affect functional alignment. The primary objective of this study was to quantify the changes in lumbo-pelvic-femoral alignment from sitting to standing in patients undergoing THA. 144 patients were enrolled. Standing and sitting radiographs using the EOS imaging system were analyzed preoperatively and 1-year postoperatively. Pelvic incidence (PI), lumbar lordosis (LL), sacral slope (SS), proximal femoral angle (PFA) and spine/femoroacetabular flexion were determined.

38 patients had multilevel DDD (26%). Following THA, patients sat with increased anterior pelvic tilt demonstrated by a significant increase in sitting lumbar lordosis (28° preop vs 35° postop; p<0.01) and sacral slope (18° vs 23°; p<0.01). Following THA, patients flexed less through their spines (preop 26° vs postop 19°; p<0.01) and more through their hips (femoroacetabular flexion) (preop 60° vs postop 67°; p<0.01) to achieve sitting position. Patients with multilevel DDD sat with less spine flexion (normal 22° vs spine 13°; p<0.01), less change in sacral slope (more relative anterior tilt) (17° vs 9°; p<0.01), and more femoroacetabular flexion (64° vs 71°; p<0.01).

For the majority of patients after THA, a larger proportion of lumbo-pelvic-femoral flexion necessary to achieve a sitting position is derived from femoroacetabular flexion with an associated increase in anterior pelvic tilt and a decrease in lumbar spine flexion. These changes are more pronounced among patients with multilevel DDD. Surgeons may consider orienting the acetabular component with greater anteversion and inclination in patients identified preoperatively to have anterior pelvic tilt or significant DDD.

Introduction. Golf is a recommended form of physical activity for older adults. However, clinicians have no evidence-based research regarding the demands on the hips of older adults during golf. The purpose of our in vivoobservational study was to quantify the hip biomechanics of older adult golfers. Methods. Seventeen healthy older male golfers(62.2±8.8 years, handicap 8.7±4.9) free from orthopaedic injuries and surgeries volunteered for participation in this IRB-approved study. A 10-camera motion capture system recorded kinematics, and two force plates collected kinetic data. Participants performed eight shots using their own driver. Data processing was performed in Visual3D. The overall range of excursion and three-dimensional net joint moments normalized to body weight for the lead and trail hips were extracted. Results. Kinematics (mean excursion and range) of lead and trail hips in all three planes during a golf swing are presented in Table 1. The trail leg experiences higher excursion in the sagittal plane, while the lead leg has more frontal plane movement. Average maximum net joint moments of the lead and trail hips were 1.2 ± 0.2 and 1.7 ± 0.3 Nm/kg, respectively. Conclusion. Our study is the first to quantify the kinematics and kinetics of the hip joint in healthy older male golfers. While the golf swing is often considered to be a predominant transverse plane motion, our results indicate considerable excursion at the hip joints in all three planes. Furthermore, the trail leg experiences 40% greater loading than the lead leg throughout the swing, suggesting that the trail leg may have a larger impact on golf performance while also leaving it more susceptible to overuse injury. For clinicians with patients who experience osteoarthritis of the hip or who have recently undergone hip surgery, this study may provide novel insight into the demands of golf on the hips. For any tables or figures, please contact the authors directly