[Study on the correlation between bony structural abnormalities and clinical symptoms in lumbar disc herniation]

To investigate the correlation between imaging characteristics of the lumbar bony structure (such as scoliosis, instability, ligament ossification, etc.) and lumbocrural pain as well as functional impairment in patients with lumbar disc herniation (LDH).

A national multi-center cross-sectional study was performed, enrolling 1 046 patients with lumbar disc herniation (LDH). Bony structural parameters were assessed using X-ray and computed tomography (CT), including scoliosis (Cobb angle >10°), lumbar curvature (normal/straightened/kyphotic), angular instability (intervertebral angular displacement≥11°), horizontal instability (intervertebral horizontal displacement ≥3.5 mm), ossification of the ligamentum flavum, intervertebral disc calcification, and ossification of the posterior longitudinal ligament. Clinical symptoms were evaluated using the visual analogue scale (VAS) for low back and leg pain, and functional status was assessed using the Oswestry disability index (ODI).

Leg VAS was positively correlated with ossification of the ligamentum flavum (r=0.080, P=0.009) and ossification of the posterior longitudinal ligament (r=0.069, P=0.025), and negatively correlated with horizontal instability (r=-0.074, P=0.017). Back VAS was positively correlated with abnormal lumbar curvature (r=0.076, P=0.014), ossification of the ligamentum flavum (r=0.070, P=0.024), and disc herniation with ossification (r=0.104, P=0.001). ODI was positively correlated with leg VAS (r=0.540, P=0.001), back VAS (r=0.585, P<0.001), and lumbar scoliosis (r=0.090, P=0.004), and negatively correlated with angular instability (r=-0.110, P<0.001).

In patients with LDH, bony structural abnormalities (especially ligament ossification and altered lumbar curvature) are partially correlated with low back and leg pain as well as functional impairment. However, pathological changes in bony structures are not the sole factor responsible for severe clinical symptoms. Clinical symptoms in LDH patients are modulated by multiple factors. Future prospective studies are warranted to verify causal relationships, and further exploration should be performed by integrating various imaging modalities and artificial intelligence techniques.