脱钙骨基质复合骨水泥修复猪股骨干缺损的生物力学评估

Biomechanical studies of material of decalcified bone matrix impregnated with bone cement as bone graft substitute in treatment of porcine femur defects

目的:近年来脱钙骨基质复合骨水泥已用于微波诱导高温原位灭活骨肿瘤性骨缺损修复,本实验拟对脱钙骨基质骨水泥复合材料修复猪股骨中段骨缺损的生物力学性能进行研究。方法:将32根猪股骨随机分为4组,分别为正常组、对照组、重建组及内固定组,后3组制成中段骨缺损,将猪脱钙骨基质与骨水泥按1∶1质量比均匀混合的复合材料充填骨缺损,其中对照组不重建,内固定组加钢板内固定,对各组分别进行三点弯曲及压缩实验。结果:内固定组与对照组差异有显著性意义,而单纯材料修复组与对照组差异无显著性意义。结论:脱钙骨基质骨水泥复合材料易于塑形,能根据需要适应不同部位骨缺损的要求,但是在骨重建的早期,对骨的生物力学性能影响不大,提示在临床上需行预防性内固定,在康复治疗阶段患者应在免负重支架的保护下活动。

AIM:The decalcified bone matrix(DBM) combined with bone cement(BC) had been us ed for the repair of bone defect caused by the bone tumors treated with microwav e-induced hyperthermia.The purpose of this study was to investigate the biomech anical behavior of composite bone substitute composed of DBM and BC implanted in bone defects created in the porcine femur.METHODS:32 porcine femurs were random ly divided into 4 groups:Group Ⅰ:Intact femur,Group Ⅱ:Standard defect,Group Ⅲ :Defect graft plus plate and Group Ⅳ:Defect plus graft.The standard bone defec ts were established in the last three groups.The defect was filled in Group Ⅲ and Group Ⅳ.Group Ⅲ were fixed with plate. Their mechanical strengths were as sessed using compression and three-point-bend tests on the INSTRON MODEL1342 m aterial testing machine to measure the maximal breaking load.RESULTS:In compress ion tests, the measurements of maximal breaking load were(12.38±0.41) kN,(9.61 ±0.09) kN,(10.23±0.49) kN and (9.50±0.47) kN respectively, and the measuremen ts were (3.41±0.57)kN,(1.08±0.10)kN,(1.60±0.19)kN and (1.00±0.17)kN in thre e-point-bend tests respectively.There was statistic difference between Group Ⅲ and Group Ⅱ(P< 0.05).There was no difference between Group Ⅳ and GroupⅡ. The differences between GroupⅠ and others group were significant(P< 0.01).CONC LUSION:The composite bone substitute possesses a superior plastic property for r epairing bone defect, but it is unable to improve the biomechanical property of bone in the early stage after surgery.When the ossification and maturation of th e regenerating tissue within the bone defect had finished, the bone would achiev es normal skeletal function in the points of biomechanical properties.So in surg ery the fixation of the bone with plate and screws was needed and the patients s hould wear the partial weight-bearing braces for early activity.