Empirical Study About Early Effect Of Tendon Bone Healing Of Rabbit Applied PDGF For Reconstruction Of Anterior Cruciate Ligament

Objective：At present, due to the growing attention focused on the issue of tendon–bonehealing, we carried out an animal study in rabbit of the use of Platelet-derived growth factorfor the promotion of this process and reconstruct the anterior cruciate ligament (ACL) in NewZealand white rabbits. From biomechanical and histological results confirmed that wetherplatelet-derived growth factor can enhance tendon bone healing to provide experimental basisfor clinical treatment of anterior cruciate ligament injury.Methods：Twenty four healthy, skeletally matureNew Zealand White rabbits (3.0–3.5kg,10–14weeks old) were prepared anterior cruciate ligament restruction models using itssemitendinsus tendons.Twenty four rabbits were randomly divided into2groups(A and B),12rabbits in each group.In the A group，15ng PDGF with0.5ml fibrin glue(FG) was injectedinto the interface between the tendon graft and the femoral bone marrow road;In B group，0.5ml FG was injected into the interface between the tendon graft and the Femoral bonemarrow road, After2,5weeks, respectively, from the experimental group and control grouprandomly selected6specimens for biomechanical testing, in the meantime, from theexperimental group and control group, respectively randomly selected6specimens forhistological evaluation.Results：By histological evaluation，we can find that the interface between the tendon graftand the bone marrow road of the experiment group at two week after ACL restructiong hadrelatively connected,we found that a great quantity of mesenchymal cells proliferate and someneovascularization in the Tendon-bone interface,but the group B of the tendon bone interfacedid not heal, we can not find significant neovascularization and new bone cell from theTendon-bone interface. The Tendon-bone interface of the group B at five week after ACLoperation had very closely connected,finding a great many of cartilage cell and neovascularization, A certain amount of osteoblast can be found at the area of bone tunnel.The space in the interface between the tendon and bone had gradually disappear and wasfilled with connective tissue composed of aligned fibro-blasts.A litte small vessels wereorganized in the loose part of the connective tissue. From biomechanical testing,contrastB,the ultimate load and stiffness of the A group at the indinidual2and5week time pointenhance by Independent-Sample Test (p＜0.05).Conclusion:1.These findings illustrate that PDGF could enhance the ultimate load to failureand stiffness in the tendon bone interface for ACLR2. PDGF can increase the number ofmesenchymal cells and neovascularization of the the tendon bone surface to promote thedevelopment of early rabbit direct tendon-bone healing.