The relationship between spino-pelvic-hip mobility and quality of life before and after total hip arthroplasty.

INTRODUCTION: Total hip arthroplasty (THA) can significantly improve quality of life (QOL) in patients with hip osteoarthritis. A relationship exists between activity levels and postoperative QOL, but its determinants are not well known. The aim of this work was to investigate the relationship between hip, pelvis and lumbar spine mobility and alignment before and after THA with QOL. MATERIAL AND METHODS: Consecutive patients with hip arthrosis and an indication for THA were included prospectively between July 2019 and December 2020, and they underwent lateral radiographs in free-standing, extension, relaxed- and flexed-seated position. Spinopelvic and hip parameters were measured, as well as their changes between positions to assess hip, pelvis and lumbar spine mobility. Patients were also administered QOL questionnaires. Data were collected preoperatively and 6 and 12 months postoperatively. RESULTS: Seventy patients were included; QOL significantly increased 6 months after THA (from 18 [10; 27] to 61 [48; 72], p < 0.001). QOL further increased by 10 points or more after 6 months in 18% of patients, while it decreased in 16%. The latter showed higher pelvic range of motion (between flexion and extension) than the former. CONCLUSIONS: This study confirmed that QOL is significantly improved by THA, and that spinopelvic alignment and function can play a role. Future work should elucidate how to better predict postoperative QOL from preoperative patient characteristics to improve patient treatment and establish early postoperative physical therapy for patients who could benefit from postoperative improvement of activity-related QOL.

The Impact of Pelvic Incidence on Spinopelvic and Hip Alignment and Mobility in Asymptomatic Subjects.

BACKGROUND: The influence of pelvic incidence (PI) on spinopelvic and hip alignment and mobility has not been well investigated. The aim of this study was to evaluate the influence of PI on spinopelvic and hip alignment and mobility, including the pelvic-femoral angle (PFA) and motion (ΔPFA), in functional positions in a cohort of asymptomatic volunteers. METHODS: This was a single-center, prospective, cross-sectional study. We included 136 healthy volunteers (69% female; mean age, 38 ± 11 years; mean body mass index, 22 ± 3 kg/m2) divided into 3 subgroups on the basis of their PI: PI < 45° (low PI), 45° ≤ PI ≤ 60° (medium PI), and PI > 60° (high PI). We made full-body lateral radiographs in free-standing, standing with extension, relaxed-seated, and flexed-seated positions. We measured the sacral slope (SS), lumbar lordosis (LL), and PFA. We calculated lumbar (∆LL), pelvic (∆SS), and hip (∆PFA) mobilities as the change between the standing (i.e., standing with or without extension) and sitting (i.e., relaxed-seated or flexed-seated) positions. RESULTS: There were significant differences between some of the 3 subgroups with respect to the LL, SS, and PFA in each of the 4 positions. There were no significant differences in ΔLL, ΔSS, or ΔPFA between the 3 groups when moving from a standing to a sitting position. PI had an inverse linear correlation with PFAextension (R = -0.48; p < 0.0001), PFAstanding (R = -0.53; p < 0.0001), PFArelaxed-seated (R = -0.37; p < 0.0001), and PFAflexed-seated (R = -0.47; p < 0.0001). However, PI was not correlated with ΔPFAstanding/relaxed-seated (R = -0.062; p = 0.48) or ΔPFAextension/flexed-seated (R = -0.12; p = 0.18). Similarly, PI was not significantly correlated with ΔLL or ΔSS in either pair of positions. CONCLUSIONS: This study confirmed that spinopelvic and hip parameters in functional positions were affected by PI, whereas lumbar, pelvic, and hip mobilities did not depend on PI. These findings suggest that hip surgeons should consider the PI of the patient to determine the patient's specific functional safe zones before and after total hip arthroplasty. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

The Impact of Hip Mobility on Lumbar and Pelvic Mobility before and after Total Hip Arthroplasty.

Hip arthrosis and total hip arthroplasty (THA) can alter a patient's balance and spinopelvic mobility. In this study, we hypothesized that lumbar, pelvic, and hip mobility and their inter-relations are affected by THA and that their study could give an insight in our understanding of postoperative balance and mobility. A total of 165 patients with hip arthrosis and with an indication for THA were included in this single-center prospective cohort. Sagittal radiographs were acquired in four positions: free-standing, standing extension, relaxed-seating and flexed-seating preoperatively and at 6 and 12 months. Spinopelvic parameters were measured (pelvic tilt and incidence, sacral slope, lumbar lordosis, pelvic-femoral angle). Standing spinopelvic parameters did not significantly change postoperatively. However, the postural changes occurring between positions were significantly altered after THA. In particular, pelvic and lumbar mobility was significantly reduced postoperatively, while hip mobility was increased. Correlations were observed between the changes in lumbar, pelvic and hip mobility before and after THA. This study confirmed that there is a relationship between lumbar, pelvic and hip mobility in osteoarthritis, and that this relationship is modified by the postoperative compensation mechanisms deployed by the patient in dynamic postures. Hence, surgeons should consider these relationships when planning surgery, in order to obtain a physiological pelvic tilt postoperatively and to account for the potential increased risk of impingement and dislocation with hip hypermobility.