Relationship of spinal alignment with muscular volume and fat infiltration of lumbar trunk muscles

Abstract

Fat infiltration and atrophy of lumbar muscles are related to spinal degenerative conditions and may cause functional deficits. Spinal alignment exerts biomechanical influence on lumbar intervertebral discs and joints. Our objective was to evaluate if spinopelvic parameters correlate with the lumbar muscle volume and fat infiltration. This is an observational, prospective and cross-sectional study. Ninety-three asymptomatic adult aged 20–40 years were included. Lumbar lordosis (LL), thoracic kyphosis (TK), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), thoracolumbar alignment (TL), sagittal vertical axis (SVA), C2-pelvic angle (CPA), spinosacral angle (SSA), lack of lordosis (PI-LL), L1S1 and T1S1 length were measured on panoramic spine radiographs. Lumbar axial T1-weighted and In- and Out-Phase images were obtained on 1.5T MRI scanner and were used to extract the muscle volumes and fat fractions of multifidus, erector spinae, and psoas. All muscle volumes were higher in men than women (p<0.05). The fat fraction was higher in the multifidus and erector spinae in women (p<0.05). Multifidus volume was weakly correlated with PT (R = 0.22), PI (R = 0.22), LL (R = 0.34) and CPA (R = 0.29). Erectors spinae volume were correlated with CPA (R = 0.21). Psoas volume correlated with TK (R = 0.21), TL (R = 0.27) and SVA (R = -0.23). The lumbar muscle volumes showed a moderated correlation with T1S1 length (R = 0.55 to 0.62). Spinopelvic parameters showed correlation with lumbar muscle volumes but not with muscle fat infiltration on asymptomatic young adults.

Spinopelvic sagittal balance: what does the radiologist need to know?

“…Research in asymptomatic individuals has shown a correlation between spinopelvic parameters and paravertebral muscle volume, although none of those parameters have been found to correlate with fatty infiltration of muscle (47) . The volume of the psoas muscle showed a positive correlation with the magnitude of the thoracic kyphosis, lumbar lordosis, and sagittal vertical axis (47) .…”

Relationship of back muscle and knee extensors with the compensatory mechanism of sagittal alignment in a community-dwelling elderly population

“…The psoas major muscle was the primary flexor of the hip joint. Xia et al demonstrated that there was no relationship between PT and the psoas muscle 36 ; whereas Menezes-Reis et al demonstrated that SVA was inversely correlated with the psoas volume 37 . Other studies have demonstrated that the magnitude of the multifidus and psoas muscle was negatively associated with the presence of a marked deformity 38 , 39 .…”

Psoas Major Muscle Volume Does Not Affect the Postoperative Thigh Symptoms in XLIF Surgery

“…Pressure against the anterior thigh from prone positioning during the surgery could also lead to thigh symptoms [ 22 ]. Moreover, degenerative spinal conditions and spinopelvic parameters were reported to affect the lumbar muscle volume, including psoas major as it originates from the transverse processes of T12–L5, and possibly cause functional deficits in the skeletal muscles [ 23 ].…”