OBJECTIVETo biomechanical analysis of the correlation between sacral tilt displacement and L₅-S₁ disc degeneration.

METHODSFrom July 2011 to July 2013, 81 patients with lumbar disc herniation and sacroiliac joint disorder including 45 males and 36 females with an average age of (45.39±1.30) years ranging from 18 to 65 years old were selected. The course of the disease ranged from 1 to 144 months with an average of (12.64±2.19) months. All patients were taken lumbar spine lateral X-ray films, the lumbar curvature angle, L₄-L₅ or L₅-S₁ intervertebral gap distance between points, and the lumbosacral angle was measured and correlated analyzed.

RESULTSThe lumbar curvature of female patients with L₅S₁DH were significantly larger than male patients [(22.18±8.62)° vs (16.17±4.97)°,<0.05]. Lumbar curvature and lumbosacral angle showed a positive correlation in LDH (=0.48,<0.01,y=7.25+0.38x,<0.01); Male patients with L₄-₅DH were more obvious (=0.55,<0.05, y=5.80+0.43x,<0.01); Female patients with L₅S₁DH were particularly evident(=0.74,<0.01,y=0.91x-5.30,<0.01). The lumbosacral angle and L₄-₅ intervertebral gap was a positive correlation in L₄-₅DH(=0.27,<0.05); While L₅-S₁ intervertebral gap and lumbosacral angle were not correlated(>0.05) in L₅S₁DH.

CONCLUSIONSThe sacral tilt displacement and L₅-S₁ disc degeneration were closely related to provide a new understanding philosophy and therapeutic approach for clinical treatment of intractable lumbar L₅S₁DH.