The Animal Experiments Of Anterior Cruciate Ligament Anatomical Reconstruction With Bone-Anterior Cruciate Ligament-Bone Allograft

Objective To compare the general morphology, biomechanics and histological results of the anterior cruciate ligament(ACL) reconstruction with Bone-Anterior Cruciate Ligament-Bone(B-ACL-B) allograft and Bone-Patellar Tendon-Bone(B-PT-B) autograft in rabbits, explore the materials and methods to restore ACL anatomically.Method 28 Japanese white rabbits were randomly divided into group A(12 rabbits,using B-ACL-B allografts), group B(12 rabbits,using B-PT-B autografts) and group C(4 rabbits, control group). The allografts and autografts were detached, and the B-ACL-B grafts were undergone liquid nitrogen deep-frozen for 2 weeks after program freezing. The maximum load, the maximum stretched length, and histological changes were evaluated 3,6, and 12 months following implantation.Results General observation:3 months after surgery, the general pattern of grafts in group A and group B was similar, the surface of gratfts was coved with synovitis, the osseous healing on the insertion can be observed. 6 months after surgery, both of the grafts is greater, the bone-bone interface is strong healing. 12 months after surgery, fiber hyperplasia in the knee is observed, osseous healing was more stable.Biomechanical testing:1,Maximum tensile load test:the group A is less than B at 3 months after transplantation (p<0.05), there is no difference in maximum tensile load between A and B at 6 months and 12 months after transplantation (p>0.05).but each maximum tensile load increases gradually from 3 months to 12 months.2,Maximum tensile length test:there is no difference both group A and group B (p>0.05). but each maximum tensile length increases gradually from 3 months to 12 months after transplantation.3,Fracture analysis of parts::there is no difference both group A and group B (p＞0.05).Histological observation:the procedure of histological transmutation in group A is similar with group B. A lot of collagen and fibroblasts were observed under the optical microscope at 3 months after transplantation, until 12 months the histological appearance of grafts is similar to normal ligament.Conclusion It can be remove the antigenicity of allotransplant preferably when use the liquid nitrogen to save the B-ACL-B allografts. There is no significant immunological rejection after ACL reconstruction and the biomechanical performance reserves better. The method of reconstruction using B-ACL-B allografts will get the similar biomechanics and histological results compared with using B-PT-B autografts. B-ACL-B grafts are more close to the anatomic structure of ACL and better to recover the function of ACL compared with B-PT-B. so, B-ACL-B can be used as more ideal material to reconstruct the ACL.