建立腰椎动静力不稳山羊模型用于椎间盘退变研究

Establishment of a goat model of lumbar static and dynamic instability for theresearch on intervertebral disc degeneration

目的:建立有应用价值的腰椎动静力不稳的山羊模型,模拟人体局部因素的影响和病理生理的应力负荷对椎间盘退变(intervertebral disc degeneration,IVDD)的作用。方法:通过腰椎动静力不稳手术(lumbar dynamic and static instability,LDSI)破坏山羊脊柱的后柱结构,包括离断竖脊肌、背阔肌、腰最长肌、棘肌等破坏腰椎动态力学稳定,离断腰椎棘突、棘上韧带、棘间韧带等破坏腰椎静态力学稳定,使腰椎产生动态力和静态力的失衡,造成脊柱后柱稳定性的丧失。以生物力学稳定性为突破点,而不破坏椎间盘结构的完整性,建立腰椎动静力不稳的山羊模型,并通过52周的术后随访,利用腰椎X线片、磁共振以及组织病理学变化等技术手术评估山羊的椎间盘高度指数(disc height index,DHI),Pfirrmann MRI分级和Masuda组织学评分等。结果:LDSI组山羊腰椎的DHI在术前0周(0.184±0.015),术后26周(0.105±0.006)和术后52周(0.075±0.007)存在差异(0周vs.26周,P<0.05;26周vs.52周,P<0.05)。LDSI组山羊腰椎的Pfirrmann分级在术前0周(1.167±0.408),术后26周(2.333±0.516)和术后52周(3.667±0.817)存在差异(0周vs.26周,P<0.05;26周vs.52周,P<0.05)。LDSI组山羊腰椎的Masuda组织学评分在术前0周(3.500±0.577),术后26周(6.250±0.957)和术后52周(8.000±0.816)存在差异(0周vs.26周,P<0.05;26周vs.52周,P<0.05)。结论:LDSI能够造成山羊椎间盘高度降低、终板边界模糊和含水量降低,在不破坏椎间盘结构完整的基础上模拟了人体长期反复劳损而导致的IVDD,更符合人体实际,有助于其发病机制的研究。

Objective:To establish a practical large animal model of intervertebral disc degeneration(IVDD)for the simulation of the influence of local factors in the human body and the role of pathophysiological stress load on IVDD.Methods:In this study,lumbar dy-namic and static instability(LDSI)surgery was performed to damage the posterior column structure of the goat spine;the muscles in-cluding erector spinae,latissimus dorsi,longissimus lumborum,and spinalis were ligated to destroy the dynamic stability of the lumbar spine,and the spinous process,supraspinous ligament,and interspinous ligament were ligated to destroy the static stability of the lum-bar spine,resulting in the imbalance of dynamic and static forces of the lumbar spine and the loss of the stability of the posterior col-umn.With biomechanical stability as the breakthrough point,a goat model of lumbar dynamic and static instability was established without destroying the structural integrity of the intervertebral disc,and during 52 weeks of postoperative follow-up,lumbar spine X-ray,magnetic resonance imaging(MRI),and histopathological changes were used to evaluate disc height index(DHI),Pfirrmann MRI grade,and Masuda histological score.Results:In the LDSI group,the DHI of goat lumbar spine was 0.184±0.015 at week 0 be-fore surgery,0.105±0.006 at 26 weeks after surgery,and 0.075±0.007 at 52 weeks after surgery(0 week vs.26 weeks:P<0.05;26 weeks vs.52 weeks:P<0.05).In the LDSI group,the Pfirrmann grade of goat lumbar spine was 1.167±0.408 at week 0 before sur-gery,2.333±0.516 at 26 weeks after surgery,and 3.667±0.817 at 52 weeks after surgery(0 week vs.26 weeks:P<0.05;26 weeks vs.52 weeks:P<0.05).In the LDSI group,the Masuda histological score of goat lumbar spine was 3.500±0.577 at week 0 before surgery,6.250±0.957 at 26 weeks after surgery,and 8.000±0.816 at 52 weeks after surgery(0 week vs.26 weeks:P<0.05;26 weeks vs.52 weeks:P<0.05).Conclusion:LDSI can cause the reduction in the height of the intervertebral disc,the blurring of endplate boundary,and the reduction in water content in goats.It simulates the process of IVDD caused by long-term repeated strain of human body with-out destroying the structural integrity of the intervertebral disc,which is more in line with the real condition of human body and may provide help for research on the pathogenesis of IVDD.