The Evaluation of the Relationship Between Psoas Muscle Atrophy and Intervertebral Disc and Facet Joint Degeneration in Patients with Lumbar Pain Using Lumbar Spine MRI

Objective: The purpose of the present study was to determine the relationship between psoas muscle lipoatrophy and facet and disc degeneration in patients with low back pain with lumbar spinal Magnetic Resonance Imaging (MRI). Material and Methods: A total of 304 patients who had low back pain were included in this retrospective cross-sectional study. The lumbar MRIs of all patients were evaluated for signs of psoas muscle atrophy. Fat content for each muscle was graded semi-quantitatively (Grade 0-4). The disc and facet joint degenerations of each patient were also graded. Psoas muscle thickness was measured in the mediolateral axial plane parallel to the vertebra. Results: It was found that the mean right psoas muscle thickness score of the patients was 35.9±7.2 mm on average, and the mean left psoas muscle thickness score was 35.8±7.1 mm. It was also found that 41.8% of the right psoas muscle degeneration was grade 1, 41.1% was grade 2, 33.6% of the left psoas muscle degeneration was grade 1, 45.1% was grade 2, 64.1% of the right facet degeneration was grade 1, 23.4% was grade 2, and 53.9% of the left facet degeneration was grade 1, and 30.3% was grade 2. Conclusion: When lumbar spine MRI examinations are evaluated, psoas muscles must also be evaluated in terms of atrophy. Indicating psoas muscle lipoatrophy in patients with low back pain may be useful for better rehabilitation planning.