兔膝关节ACL损伤后韧带内本体感受器的变化及机制

Changes of the proprioceptors in the partly injuried knee joint ACL of rabbits

目的探讨前交叉韧带(ACL)部分损伤后韧带内本体感受器形态和功能变化及机制。方法选择12只新西兰大白兔制作膝关节ACL部分损伤模型,分别于术后2、4、6个月各取4只行电生理检查(包括体感诱发电位和腘绳肌肌电图),之后分别处死,对ACL组织进行氯化金染色光学显微镜检查,评价损伤韧带内神经结构的形态功能情况。结果体感诱发电位和腘绳肌肌电图的潜伏期逐渐延长、波幅逐渐降低。ACL损伤后韧带内本体感受器数量逐渐减少,异形的本体感受器增多,体积缩小,部分结构缺失。结论 ACL损伤后韧带内的本体感受器结构出现异常,数量减少,但短期内仍能发挥一定作用,随损伤时间延长其作用逐渐减弱。机制可能与韧带损伤后强度下降,逐渐松弛,从而使韧带内神经结构在膝关节活动的过程中不能受到应有的力学刺激有关。

Objective To observe the morphological and functional changes of the proprioceptors in the partially inju- ried ACL and explore the mechanism. Methods The ACL in 12 rabbits was damaged to make animal modal. At 2-, 4- and 6-month post-operation, the ACL in 4 rabbits separately was examined with electrephysiologic study （including SEPs and EMG） and gold ehlorid staining method to judge the morphological and functional changes of the neuromechanism in the ligament tissue. Results The incubation period and wave amplitude of the SEPs and EMG degraded gradually following time. The quantity of the proprioeeptors in the injuried ACL gradually reduced following time, and the morphogenesis of the proprioceptors changed, including the volume of proprioceptors diminuted and part structure depleted. Conclusion The proprioceptors in the ligament can still have some function after ACL being injuried, but the effect weakened gradually following time. The mechanism might be that the partially injuried ACL loose gradually due to its decreased strength, and thus the proprioceptors in the ligament can not be stimulated by normal stress produced in the course of knee motion.