Is There Cervical Muscle Weakness in Patients with Loss of Cervical Lordosis? Morphometric Evaluation of Muscle Cross-Sectional Areas on MRI

The objective of this study was to compare the relative cross-sectional area (R-CSA) of the cervical muscles of two groups of patients with chronic nonspecific neck pain, with and without cervical lordosis loss, and to investigate the morphologic differences and cervical intervertebral disc degeneration status between the groups.Additionally, the study aimed to examine the effect of cervical lordosis loss on R-CSA of the cervical muscles and disc degeneration.A total of 201 patients with chronic nonspecific neck pain were included in the study, comprising 91 patients with cervical lordosis loss and 100 patients without cervical lordosis loss.The R-CSAs of both the cervical flexor and extensor muscles were retrospectively measured separately in the superficial and deep groups on magnetic resonance imaging (MRI) to determine the disc degeneration status.The R-CSA of superficial flexor, deep flexors, superficial extensors, deep extensors, total extensors, total flexors, and total cervical spine muscles were found to be significantly lower in the lordosis group with cervical lordosis loss than in the straight group without cervical lordosis loss (p < 0.01).Additionally, a significantly higher CSATFs/CSATEs (ratio of total flexor cross-sectional area (CSA) to total extensor CSA) ratio was observed in the lordosis group compared to the straight group (p < 0.01).A significant positive correlation was also observed between the R-CSA of the flexor and extensor muscles in both the lordosis and straight groups (p < 0.001).It was demonstrated that patients exhibiting a loss of cervical lordosis exhibited a high prevalence of disc degeneration, a pronounced weakness in both cervical flexors and extensors, and an imbalance between the R-CSA of the cervical flexors and extensors, which was attributed to the weakness of the extensors.