骨密度对腰椎矢状位力线和椎间盘退变程度的影响分析

Effect of bone mineral density on sagittal alignment and disc degeneration of the lumbar spine

目的研究骨密度对腰椎椎体矢状位力线及椎间盘退变程度的影响情况。方法回顾性分析46例老年腰椎病患者的术前腰椎MRI资料,根据双能X线吸收仪(DXA)测量的左侧股骨颈骨密度结果将患者分为三组:骨密度正常组(17例)、骨量减少组(19例)和骨质疏松组(10例),从腰椎矢状位MRI上测量和比较各组患者的腰椎椎体前、中、后高以及各椎间盘的前、中、后高,记录和比较各组患者腰椎各椎间盘退变程度(采用Pfirrmann分级)。结果骨质疏松组和骨量减少组腰椎各椎体高度无显著统计学差异(P>0.05),但都明显低于骨量正常组,其中椎体前高、中高的降低具有显著性差异(P<0.05)。骨质疏松组在下腰段椎间盘(腰3-4、腰4-5、腰5-1)中高有增加趋势,但骨质疏松组各椎间盘的后高都显著低于骨量减少组及骨量正常组(P<0.05)。骨质疏松组椎间盘信号退变程度要明显优于骨量减少组及骨量正常组(P<0.05)。结论骨密度情况不仅对腰椎椎体矢状位形态产生影响,而且还对椎间盘矢状位形态和退变程度产生影响,骨质疏松症患者有椎间盘退变减缓的趋势。

Objective To explore and evaluate the effect of bone mineral density （BMD） on sagittal alignment and disc degeneration of the lumbar spine. Methods Forty - six elderly subjects were classified as three groups according to varying BMD values using dual X - ray ab- sorptiometry （DXA） （17 normal, 19 osteopenia, 10 osteoporosis） and analyzed retrospectively in this study. Magnetic resonance images of their lumbar spines were obtained. The vertebral body height, intervertebral disc height and intervertebral disc degeneration grade according to Pfir- rmann classification were recorded and compared in the three groups. Results The results showed that the anterior and middle height of lumbar vertebral was significant decreased in the subjects with osteopenia or osteoporosis compared to the subjects with normal BMD. Osteoporosis was as- sociated with expansion of the middle of the 1,3 - 4, L4 - 5 and L5 -S1 disc. There was lower grade of disc degeneration in the osteoporosis group. Conclusion Osteoporosis does not only affect the morphology of the bone but also the disc of lumbar. Osteoporosis seems to play a role to prevent the disc degeneration.