| Objective:By animal experiment to research the results of non-surgery or augmentation surgery treat partial lesions of the cranial cruciate ligament (CCL) in rabbit knee, which had influenced the medial meniscus degradation of the knee joint. The purpose of this research was to provide experimental evidence on healing partial tear of anterior cruciate ligament(ACL) in clinic.Methods:This experiment used 36 ripe New Zealand White rabbits.Selected 4 rabbits into blank group randomly.Then,others underwent partial substance resection in a middle part of CCL of both sides knee from the lateral, in order to create contrast self models.One knee was selected at random as experimental group the other as contrast group.The experimental group was to simulate ACL reconstructions using the semitendinosus tendon. The contrast group did not carry out the reconstruction surgery.After surgery, at the 4,12,16,24 weeks,execute 8 rabbits,Through gross morphologic observation, and histological section for HE staining and immunity histological chemistry staining of,detect the expression of MMP-1 and MMP-13.Results:1. Gross morphologic observation:.with the times gone, the medial meniscus appears obvious degeneration:the colour from white turn to yellow; resilience descended; the edge of medial meniscus became rough,even avulsion. And in contrast group was significantly more severe than that in experimental group,while the blank group has no significant changes.2.Histological observation: the meniscal collagen fibers of contrast group showed disorder; cartilage cells became Clustering, edema,disappeare.And this process progressive increase along with times.The similar process was taken place in the experimental group, while it were much better than contrast group.3. Immunity histological chemistry:there were MMP-1 masculine chondrocytes in both experimental group and contrast group. The percentage of MMP-1 masculine chondrocytes in experimental group was significantly lower than contrast group (P<0.05)in each time piont. For the MMP-13,the time of 4W and 12W,the two groups has statistical significance (P<0.05),while 16W and 24W didn't (P>0.05)Conclusion:1. Partial rupture of the CCL could results in time-dependent degenerative changes of the rabbit medial meniscus.2. Partial CCL tears augmented with semitendinosus autograft could effectively reduce the development of medial meniscus degeneration.3. Augmented reconstructed of the CCL with semitendinosus autograft could down-regulate the expression of MMP-land MMP-13 in the medial meniscus. This maight be one of mechanisms that operation could delay the languishment of meniscus. |
