Development And Experimental Research Of The Biological Cervical Interbody Fusion Cage

Objective: Develop a new type of cervical interbody fusion cage made of allograft material.Evaluate its stability and compressive mechanical functions by biomechanical tests in adult human fresh spine specimens.Observe its influence on the fusion process and its transformation during degrading period by animal experiment .to offer basic information for its further developmentand clinical application.Method:①Design the biological cervical fusion cage made of allograft material by consulting relative literatures in recent years.②Evaluate the stability and compressive mechanical functions of the new biological cervical interbody fusion cage.③Use allograft interbody fusion cage in animal experiment,study its influence on bone fusion at different phases and reveal the degrading process of the material in spine fusion by gross observation,X-ray,CT and histological oberservation.Result:①The biological cage was successfully made which was wedge shape and made of allograft material.②The stability and compressive mechanical functions of the biological cervical interbody fusion cage meets biomechanical and clinical requirements。③The bone growth was influenced in the early stage of fusion, while at 24w ,the cage have no negative effect to the fusion,the solid bone fusion was achieved in the end at about 36w. In the early stage of fusion, the main degrading progress degradation focus on the superficial decomposition,the cage can keep its basicform. With the proceeding of fusion and degradation, the cage still can keep its basic form at 24w.In 36w the cage was disassembled and lose its form, the progress of totally degrade need a longer time.Conclusion: 1. The biological cervical interbody fusion cage not only can remain or increase the height of intervertebral space of the C-spine, but also can provide enough support and improve the stability of the lumbar spine. The design is distinctive and reasonable. It completely meets biomechanical and clinical requirements. 2. The allograft material has good tissue compatibility and will not result in evident immune reaction. It has no obvious negative influence on fusionprocess.The biological cage maintained its shape in the early time,and still enough to keep the structure from collapsing until fusion was achieved in the bone implant area . The degrading progress need a long time to totally degrade.The biological cage can anastate and retain the C-spine physiological antecurvature and segmental fusion angle and the anterior and posterior of the intervetebral disc height,can supply enough intension for the whole progress of bone graft fusion, strengthen the stability of pedical screw and rod system and prevent the subsidence and migration of the Cage. It can degrade gradually but need a long time .single Cage central implant combined with pedical fixation can achieve solid interbody fusion.