Volumetric Muscle Measurements Indicate Significant Muscle Degeneration in Single-Level Disc Herniation Patients

There is a strong relationship between lower back pain and paraspinal muscle atrophy. In this study, we aimed to investigate the prevalence of lumbar paravertebral muscle atrophy in patients with and without single-level disc herniation.

The 110 retrospectively analyzed patients in this study were divided into 2 groups. Group A included 55 patients with radiologically confirmed single-level disc herniation with back pain and radiculopathy. Group B included 55 patients with back pain without radiologic lumbar disc herniation. The paravertebral muscle cross-sectional areas were measured in both groups by 2 independent observers.

In total, 68 women and 42 men were examined. Their mean age was 40.85 years old. The mean ages of groups A and B were 42.49 and 39.22 years, respectively. The cross-sectional areas of the multifidus muscles (MM) and erector spinae muscles were significantly greater in group B than in group A (P < 0.0001). However, there were no statistically significant differences in the psoas major cross-sectional areas, disc heights, and perpendicular distances between the MM and the laminae.

The MM and erector spinae muscle groups are innervated by the dorsal root of the spinal nerve arising from the same level; therefore, long-term pressure on the root caused by disc herniation can cause atrophy and degeneration of that muscle group.