Biomechanical Testing On Tendon Bone Healing Promoted By Autologous Peripheral Blood’s Mesenchymal Stem Cells

Objective To explore the effects of autologous bone marrow mononuclearcells, which were transplanted in the tendon bone interface in reconstruction of anterior cruciate ligament, on enhancing the healing potential.Methods The autogenous MSCs of peripheral blood were isolated and cultured in vitro, which was mobilized by the granulocyte colony-stimulating factor.Forty-two immature New Zealand white rabbits were utilized and randomly divided into four groups.For the experimental group, they underwent anterior cruciate ligament reconstructions in the random knee with a long digital extensor tendon graft secured by suspensory fixation technique and injected with a mixture of MSCs and fibrin glue..Once the graft had been properly positioned in the tunnel, they were fixed using the same procedure in the fibrin glue group and the blank group.For the fibrin glue group, instead of MSCs, fibrin glue was injected into the tendon graft that would sit inside the tunnel,For the blank group, the random side underwent a similar operation with neither the MSCs nor fibrin glue injecting in the tunnel.For the normal group,with no operation.Three specimens from each group were harvested at2weeks,4weeks,8weeks and12weeks postoperatively and evaluated by conventional histological and immunohistochemical methods which include hematoxylin and eosin, toluidine blue and modified trichrome staining. control. Specimens were collected at8,12weeks after surgery respectively for biomechanical test. The maximal pull-out loads and sites of break were recordedResults In postoperative8weeks, Just one site of break of the experimental group was in the body of ligamentous,others were all in the bone tunnels of femora. There were3cases of break in tendons and3cases of break in bone tunnels in the experimental group, and there were1case of break in tendon and5cases of break in bone tunnels in the eontrol group. The difference of the pull-out loads between the two groups had statistical significance(P<O.05)in postoperative8,12weeks,Conclusion Autologous peripheral blood’s marrow mononuclearcells can enhance the tensile strength of interface of tendon and bone and benefit tendon-bone healing...