Association of Mild Leg Length Discrepancy and Degenerative Changes in the Hip Joint and Lumbar Spine

Objective The purpose of this study was to evaluate the correlation between mild leg length discrepancy (LLD) and degenerative joint disease (DJD) or osteoarthritis. Methods We evaluated standard postural lumbopelvic radiographs from 255 adults (121 women and 134 men) who had presented with spinal pain for chiropractic care. Symmetry of femoral head diameters was used to exclude magnification errors. Pearson's partial correlation was used to control for age and derive effect sizes for LLD on DJD in the hip and lower lumbar motion segments. Krippendorff's α was used for intraobserver and interobserver reliability. Results A strong correlation was found between LLD and hip DJD in men (r = 0.532) and women (r = 0.246). We also found a strong correlation between LLD and DJD at the L5-S1 motion segment in men (r = 0.395) and women (r = 0.246). At the L4-5 spinal level this correlation was much attenuated in men (r = 0.229) and women (r = 0.166). Conclusions These findings suggest an association between LLD and hip and lumbar DJD. Cause–effect relationships between mild LLD and DJD deserve to be properly evaluated in future longitudinal cohort studies.