The Basic Research And Clinical Application Of Allogeneic Bone Graft

【Objective】1.To evaluate biomechanical and pathological changes of femur cortical bone of the New Zealand rabbit in control study,the deep-frozen preservation group and the fresh group.2.Using the deep-frozen stock allogeneic bone to rebuild the large bone defects caused by trauma or tumor resection,to study the host cell immune function changes in control between preoperative and postoperative,to observe the healing of allogeneic bone and to assess the limb function after operation.【Methods】1.Basic study:50 New Zealand white rabbits were divided randomly into fresh group(control group,n=10)and the experiment group(n=40)including 4 groups:4w group(n=10),8w group(n=10),12w group(n=10)and 16w group(n=10). The rabbit bilateral femur was resected and preserved by deepfreeze for 4 weeks,8 weeks,12 weeks,and 16 weeks.After being rewarmed,each experiment groups were examined as below:the limit bending strength(n=10),the limit compressive strength (n=10),pathology examination.The control group only examined mechanical and pathology.2.Clinical study:1)36 patients,with bone tumor or trauma,underwent allogeneic bone grafting.All patients were examined with T-cell subsets in lw preoperative and 14d,21d,28d postoperative.2)According to X-ray and ⁹⁹Tcm-MDP examination after operation in 3 months,6 months and 12 months,to observe the bone healing.3)According to Mankin functional assessment criteria,to assess the limb function of allogeneic bone graft after operation.【Results】1.Basic study:Compared with control group,the biomechanical of the experiment group reduced with no analysis meaning:limit bending strength (f=0.156,p=0.959),the limit compressive strength(f=0.907,p=0.468).Microstructure of femur cortical in experiment groups had no significant change.2.Clinical study:1)36 patients underwent allogeneic bone grafting successfully.Compared to 1w preoperative status,the immune function reduced in 7d postoperative(P＜0.05), improved in 14d and recovered in 28d(P＞0.05).No cellular immune rejection occurred apparently.2)36 patients were followed up from 6 to 29 months(average 19 months).According to X-ray,radio-nuclide ⁹⁹Tcm-MDP bone scan and the clinical signs,the healing time of allogeneic bone were 4 to 13 months(an average of 5.6 months).34 cases of allogeneic bone healed successfully,2 cases non-union.Tumor recurrence in four cases and 1 case infected healing after anti-infection treatment.3) Assessment by Mankin limb function standard assessment:21 cases excellent,7 cases good,6 cases common,2 cases poor and good rate was 77.8%(28/36).【Conelusion】1.The biomechanical strength of allogeneic bone preserved by Deep-frozen in short-term was stabile in short-term.2.The host cell immune function had no significant changes after allogeneic bone graft.3.The allogeneic bone can healed successfully in host.4.The allogeneic bone being preserved in deep-frozen is a satisfactory material to repair bone defects.