| Along with the development of the society, people are getting more and more easily get spinal trauma and retrogressive diseases of the spinal column. The cure of these kinds of diseases is mainly fusion of the vertebrae, but all the fusion cages used domestic and overseas have certain shortcomings. In out study, we plan to estimate the allograft fusion cage (AFC), a fusion cage we manufactured by ourselves, by biomechanical evaluation, toxicity trials, animal experiments and clinical observations. And want to make it certain that making up some flaws of other cages being used now, it is a better fusion cage which can be used all over the country with its advantages of micro-wound, guaranteed-fixation, easily-operated, money-saving and bio-absorption.Materials and Methods1. Eight cervical vertebral specimens were used, the C3-T1 segment were embedded in polynmethyl methacrylate (PMMA). Ruler used for the spin 3-demensional movement analysis system to identify were fixed in the front of the C3-T1 vertebrae, put the control group, in which the intervertebral disc of the C5 ~ 6 segment were token out, AFC-implanted group and ilium-implanted group on the spin 3-demensional movement analysissystem respectively, by imitating the movement of the spine column in the human body, the cervical vertebrae were made to move to every corresponded direction when loaded with 2.0N-m pure moment. Two cameras put in different angle captured the images of the vertebrae's movements under zero-load and maximum-load. All the images were analyzed by the computer, and the stability of the cervical vertebrae in every group was estimated.2. Four specimen of C4 ~ 5 segment implanted by AFC were put in SWD-10 material trial machine (Changchun trial machine institute) ,the vertebrae were loaded with vertical pressure, the extent to which the bone were destroyed were noted down; in other 4 specimen of C4 ~ 5 segment, AFC and ilium were implanted successively, pull-out load were inflicted , dislocation intense were noted ;finally, ilium were implanted and the press and destroy-trial were carried out.3. 8 fresh adult swine spine column specimen were used.T127 segment were buried by( PMMA ), and the specimen were divided into: normal group, specimen of normal vertebral column; fixation group: vertebral column fixed with steffee plate; AFC group: After handled the same as the fixation group, the AFCs (one in the middle, two in middle, and one tilted) were screwed into the spinal column at random. All the specimen were put on the Material Test System 858.02 ( Minneapolis, Minisota, USA ), stretch instrument were put between the trial segment, the displacement of the segment during the loading process were measured, the axis pressed rigidity under every circumstances were analyzed.1. The geometric model of the Steffee plate used were made according tothe actual size of the plate, the material property were given, Tetrahedroncell were adopted and the gridding were drawn, the lower screw of the plate were fixed and vertical displacement load were given, the Vion Mise stress distribution when the displacement were 0.5mm, 2.8mm were gotten respectively.2. AFCs were sterilized by one of the following 5 methods :70% alcohol solution, 500mg/L epoxyethane, 1:1000 thimerosal, 15-20KGy Co-60, or the combined sterile method .After this procedure, each AFC was scraped into pieces under axenic condition, trained in aerobic and anaerobic medium, separately, cultured in 37C for 24-48 hours. The sterile successful rate of each group was calculated.3. 48 healthy SD rats were divided into 4 groups at random, the allograft bone, processed by combined sterilization method and pure ether sterilization method immersion, is transplanted into the rats' bodies. Having being bred for 90 days, The rats were checked by the vital characteristics, the blood routine examination, biochemistry and viscera pathology .4. 15 sheep underwent anterior C2, 3 intervertebral fusions with an AFC. Sheep were radio g... |
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