Luk K D, Ruan D K, Chow D H, Leong J C
Department of Orthopaedic Surgery, University of Hong Kong, China.
Clin Orthop Relat Res. 1997 Apr(337):13-26. doi: 10.1097/00003086-199704000-00003.
Fusion of the spine while restoring stability of the spinal segment, fails to preserve spinal mobility. Long term complications of accelerated degeneration in the neighboring segments have been reported. The present study explores the possibility of intervertebral disc autografting in a bipedal animal model by isolating a lumbar disc together with the adjacent end plates and repositioning it with minimal internal fixation. Fourteen Rhesus monkeys were sacrificed at 2, 4, 6, and 12 months after surgery and the grafted discs were examined radiologically, biochemically, pathologically, and biomechanically. Healing of the bony end plate was seen between 2 to 4 months postoperatively. There was early loss of disc height at 2 and 4 months but there was a suggestion of some reconstitution up to 12 months. There was minimal evidence of gross degeneration at all stages. Gradual loss of water content was found in the annulus and the nucleus. The nucleus pulposus seemed to be able to reaccumulate proteoglycan after an initial drop in the first 4 months. There was significant increase in hydroxyproline content in the annulus fibrosus and the nucleus pulposus. Biomechanically, the grafted disc showed hypermobility in the first 4 months but gradually became stabilized with time. Results from this study suggested that a fresh intervertebral disc autograft could survive a period of ischemia. Although the physiology of the disc was deranged, it was able to preserve a certain degree of segmental mobility without sacrificing stability. Further studies are required to validate these results and the field of disc allografting should be explored.
脊柱融合术在恢复脊柱节段稳定性的同时，无法保留脊柱的活动度。已有报道称相邻节段加速退变会引发长期并发症。本研究通过在双足动物模型中分离出腰椎间盘及其相邻终板，并在进行最小限度内固定的情况下重新植入，探索椎间盘自体移植的可能性。14只恒河猴在术后2、4、6和12个月被处死，对移植的椎间盘进行影像学、生物化学、病理学和生物力学检查。术后2至4个月可见骨终板愈合。术后2个月和4个月时椎间盘高度早期降低，但至12个月时有一定程度的恢复迹象。在所有阶段，大体退变的证据都很少。在纤维环和髓核中发现水分含量逐渐减少。髓核在前4个月初始下降后似乎能够重新积累蛋白聚糖。纤维环和髓核中的羟脯氨酸含量显著增加。生物力学方面，移植的椎间盘在最初4个月表现为活动度过高，但随时间推移逐渐稳定。本研究结果表明，新鲜的椎间盘自体移植能够在一段缺血期内存活。尽管椎间盘的生理功能紊乱，但它能够在不牺牲稳定性的情况下保留一定程度的节段活动度。需要进一步研究来验证这些结果，并探索椎间盘同种异体移植领域。
