Spinopelvic alignment and low back pain after total hip arthroplasty: a scoping review

Pourahmadi et al. BMC Musculoskeletal Disorders (2022) 23:250 https://doi.org/10.1186/s12891-022-05154-7 Open Access RESEARCH Spinopelvic alignment and low back pain after total hip arthroplasty: a scoping review Mohammadreza Pourahmadi1 , Mohammad Sahebalam1, Jan Dommerholt2,3,4 , Somayeh Delavari5 , Mohammad Ali Mohseni‑Bandpei6,7 , Abbasali Keshtkar8 , César Fernández‑de‑Las‑Peñas9,10 and Mohammad Ali Mansournia11* Abstract Objective: Spinopelvic alignment is increasingly considered as an essential factor for maintaining an energy-efficient posture in individuals with normal or pathological status. Although several previous studies have shown that changes in the sagittal spinopelvic alignment may occur in patients undergoing total hip arthroplasty (THA), no review of this area has been completed so far. Thus, the objective of this scoping review was to summarize the evidence investigat‑ ing changes in spinopelvic alignment and low back pain (LBP) following THA. Data sources: We adhered to the established methodology for scoping reviews. Four electronic databases were systematically searched from inception-December 31, 2021. Study selection: We selected prospective or retrospective observational or intervention studies that included patients with THA. Data extraction: Data extraction and levels of evidence were independently performed using standardized checklists. Data synthesis: A total of 45 papers were included in this scoping review, involving 5185 participants with THA. Pelvic tilt was the most common parameter measured in the eligible studies (n = 26). The results were not consistent across all studies; however, it was demonstrated that the distribution of pelvic tilt following THA had a range of 25° posterior to 20° anterior. Moreover, decreased sacral slope and lower pelvic incidence were associated with increased risk of dislocation in patients with THA. Lumbar spine scoliosis did not change significantly after THA in patients with bilateral hip osteoarthritis (5.50°(1.16°) vs. 3.73°(1.16°); P-value = 0.29). Finally, one study indicated that LBP improve‑ ment was not correlated with postoperative changes in spinopelvic alignment parameters. Several methodological issues were addressed in this study, including no sample size calculation and no type-I error adjustment for outcome multiplicity. Conclusions: Changes in spinopelvic alignment may occur after THA and may improve with time. Patients with a THA dislocation usually show abnormal spinopelvic alignment compared to patients without a THA dislocation. LBP usually improves markedly over time following THA. Keywords: Arthroplasty, Replacement, Hip, Spinopelvic alignment, Spine, Low back pain, Review *Correspondence: 11 Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Poursina St., Shanzdah‑e Azar St., P. O. Box: 6446‑14155, Tehran, Iran Full list of author information is available at the end of the article Background Assessment of spinopelvic alignment is gaining increasing importance and attention, not only in spinal surgery but also in hip surgery [1]. Spinopelvic alignment is a complex chain of correlations from the spine to © The Author(s) 2022. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativeco mmons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. Pourahmadi et al. BMC Musculoskeletal Disorders (2022) 23:250 the pelvis and that changes in one region of the spine can result in reciprocal changes in other spinopelvic regions with potential alignment consequences [2]. The literature has shown that imbalanced spinopelvic alignment is associated with worse function and poor quality of life in patients with spine and hip disorders [3]. Hence, efficient performance of daily human activities requires an ideal coordinated motion between the spine, pelvis, and hips. A good example of normal relative motion between the adjacent segments is standto-sit movement, in which flattening (or flexion) of the lumbar spine, a posterior tilt of the pelvis, and flexion of the hips happen [4]. Spinopelvic alignment and kinematic imbalance following total hip arthroplasty (THA) may change the functional position of the acetabulum, creating a potential for dislocation [5, 6]. THA is one of the most common, cost-effective, and clinically successful surgeries performed today for the treatment of arthritic hip disorders [7–9]. It provides reliable outcomes for patients suffering from end-stage degenerative hip osteoarthritis (OA), especially pain relief, functional restoration, and overall improved quality of life [8]. Although THA is referred to as ‘the operation of the century’ in 2007 [10], it not without potential complications and consequences. Healy et al. (2016) [9] listed the potential complications of THA including bleeding, wound complication, thromboembolic disease, neural deficit, periprosthetic fracture, dislocation or instability, abductor muscle disruption, deep periprosthetic joint infection, vascular injury, implant loosening, osteolysis, and so forth. Furthermore, changes in the spinopelvic alignment may occur in patients after THA [11]. Heckmann et al. (2018) [6] alleged that spinopelvic imbalance may serve as a causative factor for late dislocations after THA. Lateral spine-pelvis-hip radiographs may provide a radiographic explanation for both instability and the direction of the dislocation. Various spinopelvic alignment parameters have been evaluated before or after THA, including pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), sagittal vertical axis (SVA), lumbar lordotic (LL) angle, thoracic kyphosis (TK) angle, and coronal lumbar angles [6, 11–13]. The PI, which is the algebraic sum of the PT and SS, is a constant morphologic parameter that helps clinicians to predict the physiologic individual sagittal range of motion of the pelvis [14]. The PI does not change with different ages and in between the sexes [15], and it is an important parameter for determining the spinal balance [16 (...truncated)