The Impact of Global Spinal Alignment on Standing Spinopelvic Alignment Change After Total Hip Arthroplasty

Abstract

Study Design: Retrospective cohort study. Objectives: The interactions between hip osteoarthritis (OA) and spinal malalignment are poorly understood. The purpose of this study was to assess the influence of total hip arthroplasty (THA) on standing spinopelvic alignment. Methods: In this retrospective cohort study, patients undergoing THA for OA with pre-and postoperative full-body radiographs were included. Standing spinopelvic parameters were measured. Contralateral hip was graded on the Kellgren-Lawrence scale. Pre-and postoperative alignment parameters were compared by paired t-test. The severity of preoperative thoracolumbar deformity was measured using TPA. Linear regression was performed to assess the impact of preoperative TPA and changes in spinal alignment. Patients were separated into low and high TPA (<20 or >/=20 deg) and change in parameters were compared between groups by t-test. Similarly, the influence of K-L grade, age, and PI were also tested. Results: 95 patients were included (mean age 58.6 yrs, BMI 28.7 kg/m2, 48.2% F). Follow-up radiographs were performed at mean 220 days. Overall, the following significant changes were found from pre-to postoperative: SPT (14.2 vs. 16.1, P = 0.021), CL (−8.9 vs. −5.3, P = .001), TS-CL (18.2 vs. 20.5, P = .037) and SVA (42.6 vs. 32.1, P = .004). Preoperative TPA was significantly associated with the change in PI-LL, SVA, and TPA. High TPA patients significantly decreased SVA more than low TPA patients. There was no significant impact of contralateral hip OA, PI, or age on change in alignment parameters. Conclusion: Spinopelvic alignment changes after THA, evident by a reduction in SVA. Preoperative spinal sagittal deformity impacts this change. Level of evidence: III.

Risk Factors for Progressive Spinal Sagittal Imbalance in the Short-Term Course after Total Hip Arthroplasty: A 3 Year Follow-Up Study of Female Patients

“…Furthermore, ROC analysis showed that ATMS ≤ 4.3 kPa and SS ≤ 31.9° were associated with spinal sagittal imbalance and may be useful predictors of progressive spinal sagittal imbalance before THA. Although many reports evaluated spinopelvic alignment immediately after THA [ 10 , 11 , 12 , 22 , 23 , 24 , 25 , 26 ], to our knowledge, no studies have reported the risk of spinal sagittal imbalance in the long-term course after THA. Spinal sagittal imbalance after THA may lead to a demand for corrective surgery.…”

“…This study showed that a small SS causes spinal sagittal imbalance 3 years after THA in female patients. Patients with hip OA usually have increased SVA due to anterior pelvic tilt caused by hip flexion contracture [ 11 ]. The mean values of SS and PT of Japanese women in their 60s were 31° and 18°, respectively [ 35 ].…”

“…Total hip arthroplasty (THA) is the standard procedure for hip OA, and the number of THAs being performed is increasing [ 9 ]. In general, THA reduces flexion contracture of the hip joint, resulting in a retroverted pelvis, decreased SVA, and improved spinal sagittal balance [ 10 , 11 , 12 ]. However, in some cases, spinal sagittal imbalance with lumbar kyphosis develops in the course after THA.…”

Hip replacement improves lumbar flexibility and intervertebral disc height — a prospective observational investigation with standing and sitting assessment of patients undergoing total hip arthroplasty

“…Thereby, it was demonstrated that re-storing of the sagittal spinal alignment might led to a decrease in posterior pelvic tilt and acetabular anteversion [4,32,33]. However, only a few investigations assessed the influence of hip replacements on the spinopelvic complex [14,22,34]. Weng et al examined the changes in spinopelvic alignment after THA in a patient cohort with confirmed LBP demonstrating a significant alteration in T1 spinal-pelvic inclination, pelvic-femoral angle and a significantly reduced prevalence of LBP post-operatively [14].…”

“…The improvement of health-related quality of life due to an enhanced disc intervertebral height in patients with LBP has already been demonstrated [20]. Osteoarthritis of the hip and its related pain is associated with abnormal posture; this might contribute to the development of LBP [21,22]. However, some studies have reported decreased LBP after THA, but the underlying mechanisms have not yet been identified [14,[23][24][25][26].…”