Is the Lipid Content of the Psoas Major Correlated with Chronic Low Back Pain and Spinopelvic Alignment? A Magnetic Resonance Spectroscopic Study

• Main Authors: Izaya Ogon, Hiroyuki Takashima, Tomonori Morita, Tsutomu Oshigiri, Yoshinori Terashima, Mitsunori Yoshimoto, Makoto Emori, Atsushi Teramoto, Tsuneo Takebayashi, Toshihiko Yamashita
• Format: Article
• Language: English
• Published: Korean Spine Society 2020-08-01
• Series: Asian Spine Journal
• Subjects: low back pains; psoas muscle; spinopelvic alignment; magnetic resonance imaging
• Online Access: http://www.asianspinejournal.org/upload/pdf/asj-2020-0042.pdf

Study Design Cross-sectional observational study. Purpose This study aimed to analyze any potential associations of extramyocellular lipid (EMCL) and intramyocellular lipid (IMCL) contents with (1) the intensity of low back pain (LBP); (2) age, cross-sectional area (CSA), and fatty infiltration (FI) of the psoas major; and (3) spinopelvic parameters. Overview of Literature The psoas major has clinically relevant function; however, the association of this muscle with chronic LBP is controversial. Magnetic resonance spectroscopy enables a detailed analysis of the composition of muscular fat tissues such as its EMCL and IMCL contents. Methods The study population comprised 40 patients (19 males, 21 females; mean age, 61.7±2.4 years). Possible correlations of LBP Visual Analog Scale (VAS) scores, age, CSA, FI, and spinopelvic parameters with EMCL and IMCL contents of the psoas major were assessed. Results No association was identified between the EMCL and IMCL contents and LBP VAS scores (r=0.05, p=0.79 and r=0.06, p=0.75, respectively). The EMCL content correlated with age (r=0.47, p<0.01), body mass index (BMI) (r=0.44, p<0.01), CSA (r=−0.59, p<0.01), and FI (r=0.49, p<0.01). EMCL content showed a significant negative correlation with sacral slope (SS) (r=−0.43, p<0.05) and positive correlation with pelvic tilt (PT) (r=0.56, p<0.01). Conclusions EMCL content correlated with age, BMI, CSA, and FI of the psoas major, while IMCL content had no correlation. This study found correlations between SS and PT and EMCL content of the psoas major, but no correlations were found between spinopelvic parameters and IMCL content of the psoas major.