170 Disc Space Height in Relation to Neural Foraminal Dimensions and Patient Characteristics: A Morphometric Analysis From L1-S1 Using Computed Tomography

Abstract

INTRODUCTION: The normative relationship between lumbar intervertebral disc space height (DSH) and neuroforaminal dimensions (NFD) has yet to be defined. METHODS: Anterior, middle, and posterior DSH were measured on 350 female and 350 male patients between 18 and 35 years of age without spinal pathology. NFD were defined as sagittal anterior-to-posterior (AP) width, axial AP width, foraminal height, and area. Statistical analyses were performed to assess associations among DSH, NFD, and patient height, weight, body mass index, sex, and ethnicity. RESULTS: DSH measurements demonstrated increasing, linear trends moving caudally from L1-L2 to L5-S1, while NFD demonstrated a unimodal distribution pattern with largest NFD at L3-L4 and smallest NFD at L1-2 and L5-S1. Accounting for confounding due to height, weight, and ethnicity, male patients demonstrated larger DSH compared to female patients across all levels L1-S1 (p < .001). Asian patients demonstrated taller DSH compared to Caucasian, Hispanic, and African-American patients across all levels L1-S1 (p = .014). Zero moderate or strong correlations were observed between DSH and NFD measurements or patient characteristics for all levels L1-S1, though weight and foraminal height were weakly (r = .3) associated with increased DSH (p < .001). CONCLUSIONS: This study describes 38,500 CT-based L1-S1 disc space height and neuroforaminal measurements in young patients without spinal pathology. Among these patients, disc space height follows an increasing trend moving caudally from L1-S1, while foraminal dimensions demonstrate a unimodal distribution clustered at L3-L4. Neuroforaminal dimensions, including foraminal height, are not moderately or strongly associated with disc space height. Disc space height is influenced by sex and ethnicity but is not moderately or strongly influenced by patient height, weight, and BMI.