Angiogenic effect of basic fibroblast growth factor on anterior cruciate ligament reconstruction with freeze-dried tendon implants at early stage: A histological observation / 中国组织工程研究

ABSTRACT

BACKGROUND: Based on previous studies, the combination of basic fibroblast growth factor (bFGF) with graft may accelerate the procedure of vascular invasion of anterior cruciate ligament (ACL) graft. The antigenicity of graft could be inhibited by the destruction of major histolocompatibility complex (MHC) through the treatment of allogenous tendon by freeze. The freeze. dried tendon showed advantages including prolonged storage time. availability for transport and possibility of commercial application. There is no experimental and clinical study on the graft substance of bFGF combined tendon in ACL reconstruction in animal model so far. OBJECTIVE: To observe histologically the effect of exogenous application or bFGF combined to freeze-dried tendon on angiogenic enhancement in early ACL reconstruction. DESIGN, TIME AND SETTING: Controlled animal study, which was performed in the Department of Orthopeadics, Xijing Hospital. Fourth Military Medical University of Chinese PLA between June 2006 and June 2007.MATERIALS Fourteen dogs were used in the experiment. METHODS: Extensor digitorum longus tendon was harvested from the rest 2 dogs and treated by freeze-dry as graft for other experimental dogs. bFGF(100 u g/L)was combined to freeze-dried tendon and then transplanted into one side knee to substitute the original ACL. While only freeze-dried tendon was used in the transplantation at the other side as control. MAIN OUTCOME MEASURES: Twelve of them were randomly divided into 6 groups according to the 6 time points,i,e.,1,2,3,4,5,6 weeks after surgery(2 dogs in each group).The histological observation with HE staining was done under microscope to mainly observe the angiogenesis in the transplanted ACL. RESULTS: Neovascularization occurred at the 2nd to 3rd weeks and reached the peak at the 4th to 5th weeks postoperatively at the experimental sides. By contrast. The neovascularization occurred at the 4th to 5th weeks postoperatively at the control sides. Neovascularization in the combined group was longer and deeper than that in the control group. CONCLUSION: The time of neovascular formation and the depth of vascular penetration into the tendon in the group of bFGF combined to freeze-dried tendon are superior to those in the control group.