Analysis of the Thickness of Ligamentum Flavum and Its Relationship With Degenerative Disc Changes at L3-4, L4-5, and L5-S1 Levels in Patients Undergoing Magnetic Resonance Imaging (MRI) of the Lumbosacral Spine

Background Low back pain (LBP) is the leading cause of disability among working-age adults, with its prevalence increasing with age and peaking in the 45-54 age group. It is common practice for clinicians to conduct advanced imaging procedures, such as computed tomography (CT) and magnetic resonance imaging (MRI) when a patient presents with LBP. The objective of this study was to measure and analyze the width of the ligamentum flavum (LF) on each side and the extent of degeneration of the disc at the L3-4, L4-5, and L5-S1 levels. Methods The current investigation was a cross-sectional descriptive-analytical effort carried out in the radiodiagnosis department of Sri Devaraj Urs Medical College, Tamaka, Kolar, from July 2024 to September 2024. The study's inclusion criteria were participants in age groups ranging from 20 to 60 years who were referred for an MRI of the lumbosacral spine and had a prior history of LBP. Results Out of 60 subjects, 26 (43.3%) individuals were females, and 34 (56.7%) individuals were males. Out of the maximum number of patients, 23 (38.3%) were within the age range of 31-40 years. The medial and lateral aspects of the LF measurements showed an increase with age, with lateral values being greater than the medial measurements (p = 0.001). The mean thickness of the ligament and the mean height of the disc showed significant variations at all levels. Statistically significant differences were seen in the thickness of the LF of male patients (4.82, 0.62 mm) compared to female patients (4.89, 0.72 mm). A statistically significant positive Pearson association was observed between the thickening of the LF and Pfirrmann grading of degenerative disc disease (DDD). Conclusion The LF thickness is significantly associated with disc degeneration, especially at the L4-L5 level, contributing to spinal canal stenosis, which is critical for the management of LBP.