Characterization of Lumbar Lordosis: Influence of Age, Sex, Vertebral Body Wedging, and L4-S1.

Abstract

Retrospective radiographic review. The objectives of the study were to determine the contributions to lumbar lordosis (LL) through both the vertebrae and the intervertebral disc (IVD), and to investigate the relationships between lumbar sagittal spine measurements and age and gender. A small body of literature exists on the relative contributions of vertebral body and IVD morphology to LL, the effects of L4-S1 on overall LL, and the relationships/correlations between lumbar sagittal spine measurements. Patients who met the inclusion criteria were retrospectively evaluated. Measurements included LL, pelvic incidence (PI), and % contributions of vertebral body wedging/IVD wedging/L4-S1 to LL. Patients were separated into groups by age and sex, demographic data were collected, and statistical analysis was completed. LL decreased with age, although PI remained similar. Females demonstrated increased LL and vertebral body wedging % than males. Males demonstrated increased L4-S1% than females. Despite a decrease in LL with age, patients maintained L4-S1% and IVD wedging %. There was a significant negative relationship between PI and IVD wedging, PI and L4-S1%, and LL and L4-S1%. During aging, the lumbar spine loses LL linearly. This occurs in the IVD and vertebral bodies. Females have increased LL compared with males, because of an increase in vertebral body wedging and IVD/vertebral wedging cranial to L4. In patients with high PI or LL, increased LL occurs from cranial to L4 and from vertebral body wedging.