Magnetic resonance imaging correlation between lumbar disc herniation and multifidus muscle degeneration

Abstract Background A causal connection may exist linking upper lumbar disc herniation (ULDH) and multifidus muscle (MF) degeneration. This work tried to find the link between ULDH and MF affection by correlating muscle parameters with disc herniation grades to recognize their relation, and so, improving care and follow-up for these patients. Methods The clinical and radiological magnetic resonance imaging (MRI) data of 26 patients with lower back pain due to ULDH and another 26 comparable healthy controls during a year (from July 2023 to June 2024) were retrospectively studied. In addition to the basic data, the disc herniation site and grade, MF indices, including fatty infiltration percentage, were recorded. Results On comparing controls with ULDH patients, no significant differences were found in age, sex, and BMI ( P > 0.05). On the other hand, there were significant differences ( P < 0.01) in their MF total muscle cross-sectional area (MCSA), Pure (MCSA), muscle width, and their fatty infiltration degree, with significant correlations of these muscle indices with their fatty affection. Moreover, ULDH grades were significantly increased with age, in males ‘ sex, and with higher degrees of muscle atrophy, specifically total and pure MCSA. Furthermore, significant differences in all parameters did not appear between L2/3 and L3/4-disc herniation (except more atrophy of the muscle width in males) and between left and right affection. Conclusion A remarkable association of FM atrophy and LDH could be present, as a mutual impact and interplay process. So, physiotherapy for the back muscles should be planned to avoid their atrophy, especially after ULDH.