Does paraspinal muscle morphometry predict functional status and re-operation after lumbar spinal surgery? A systematic review and meta-analysis

Abstract

Objectives Whether paraspinal muscle degeneration is related to poor clinical outcomes after lumbar surgery is still indistinct, which limits its clinical application. This study aimed to evaluate the predictive value of paraspinal muscle morphology on functional status and re-operation after lumbar spinal surgery. Methods A review of the literature was conducted using a total of 6917 articles identified from a search of PubMed, EMBASE, and Web of Science databases through September 2022. A full-text review of 140 studies was conducted based on criteria including an objective assessment of preoperative paraspinal muscle morphology including multifidus (MF), erector spinae (ES), and psoas major (PS) in addition to measuring its relationship to clinical outcomes including Oswestry disability index (ODI), pain and revision surgery. Meta-analysis was performed when required metrics could be calculated in ≥ three studies, otherwise vote counting model was a good alternative to show the effect direction of evidence. The standardized mean difference (SMD) and 95% confidence interval (CI) were calculated. Results A total of 10 studies were included in this review. Of them, five studies with required metrics were included in the meta-analysis. The meta-analysis suggested that higher preoperative fat infiltration (FI) of MF could predict higher postoperative ODI scores (SMD = 0.33, 95% CI 0.16–0.50, p = 0.0001). For postoperative pain, MF FI could also be an effective predictor for persistent low back pain after surgery (SMD = 0.17, 95% CI 0.02–0.31, p = 0.03). However, in the vote count model, limited evidence was presented for the prognostic effects of ES and PS on postoperative functional status and symptoms. In terms of revision surgery, there was conflicting evidence that FI of MF and ES could predict the incidence of revision surgery in the vote count model. Conclusion The assessment of MF FI could be a viable method to stratify patients with lumbar surgery by the risk of severe functional disability and low back pain. Key Points • The fat infiltration of multifidus can predict postoperative functional status and low back pain after lumbar spinal surgery. • The preoperative evaluation of paraspinal muscle morphology is conducive for surgeons.

Examining the Role of Paraspinal Musculature in Post-Operative Disability after Lumbar Fusion Surgery for Degenerative Spondylolisthesis

“…In recent literature, the role of the paraspinal musculature (PM) has emerged as an important factor affecting spinal pathologies and postoperative complications. 6,7 The PM is composed of the posterior muscles (multifidus and erector spinae) and the anterior psoas muscle. 8 The posterior PM is especially critical for load distribution and stability of the spine by providing intersegmental stabilization and dorsal tension to counteract the anterior to the vertebral column lying center of mass.…”

“…19 A review from Han et al reported strong evidence for an increased risk of bone nonunion, screw loosening, and adjacent segment disease after lumbar fusion in cases of PM atrophy. 7 Despite this mounting evidence, the association between PM and patient-reported outcomes in lumbar fusion surgery is unclear, highlighting a critical area for further research. The goal of this study is to examine how the composition of the PM influences patient-reported outcomes after lumbar decompression and fusion surgery in patients with DLS, with the hypothesis that atrophy of the PM reduces improvements in disability after surgery.…”

“…Understanding the risk factors for unfavorable surgical outcomes is necessary for optimizing patient selection and prehabilitation. In recent literature, the role of the paraspinal musculature (PM) has emerged as an important factor affecting spinal pathologies and postoperative complications 6,7 …”

“…Recent studies have highlighted the role of the PM in the context of bone quality, 14,15 spinal alignment, 16,17 the development of proximal junctional failure, 18 and patient-reported outcomes after cervical decompression 19 . A review from Han et al reported strong evidence for an increased risk of bone nonunion, screw loosening, and adjacent segment disease after lumbar fusion in cases of PM atrophy 7 …”