Elucidation of the natural healing mechanism after knee anterior cruciate ligament tear and it's clinical application

应用力学、组织学和电化学方法，观察了一种新的前交叉韧带（ACL）断裂动物模型的自然愈合情况。用微型剪刀完全切断ACL，然后用人工韧带正常控制膝关节。所有大鼠的ACL断裂均愈合。ACL切割后8周，愈合韧带中的III型胶原蛋白增加。ACL切断后8周和40周，愈合韧带强度为正常韧带的一半，内、外侧半月板和断裂ACL中MMP-1、MMP-13和TIMP-1的表达均增加。与无关节对照组相比，关节对照组中MMP-13的表达受到抑制。提示重力作用下关节运动异常增加了膝关节半月板和前交叉韧带断裂处蛋白水解酶的表达。

The natural healing of the ruptured anterior cruciate ligament(ACL) using a new animal model was observed by mechanical, histological and immunohistochemistrical methods. The ACL was cut completely by the mini-scissors and then the knee joint was controlled normally with artificial ligament. The ruptured ACL was healed in all rats. Eight weeks after ACL cutting, the Type III collagen was increased in the healing ligament. After 8 weeks and 40 weeks after the ACL cut, the healing ligament was half strength compared to the normal ligament.The expression of MMP-1, MMP-13 and TIMP-1 in medial and lateral meniscus and rupture ACL was increased after ACL cut. Expression of MMP-13 in the joint control group has been suppressed compared to the no joint control group. It is suggested that abnormal joint movement under the gravity is increased to express of proteolytic enzymes of both meniscus and rupture ACL in the knee joint.