Evaluation of paravertebral muscle atrophy and fatty degeneration in patients with axial spondyloarthritis

Abstract

Sarcopenia or muscle atrophy is a common feature of many chronic diseases of the musculoskeletal system including those accompanied by chronic low back pain (LBP). The aim of the study was to evaluate the morphological changes of the muscles in the lumbosacral region in patients with axial spondylarthritis (AxSpA) who underwent magnetic resonance imaging and to compare those changes with a group of patients with chronic low back pain of other etiology. A total of 82 patients with chronic LBP were studied, divided into three groups of interest-first group-controls with low back pain, the second group-patients with ankylosing spondylitis, and the third group-with non-radiographic AxSpA (nr-AxSpA). All patients underwent radiography and magnetic resonance imaging of the sacroiliac joints. The area of the following three paravertebral muscles was measured: Lumbar multifidus muscle, erector spinae muscle, and psoas muscle. The available fatty infiltration of those muscles was graded (0-4). The area of the investigated paraspinal muscles did not differ significantly among the three study groups (p > .05). Multiple linear regression analysis determined that C-reactive protein was a predictor of the measured area of multifidus muscle (p