The basic researchfor composite bone cement of calcium phosphate and cancellous bone granules / 中华骨科杂志

ABSTRACT

Objective To probe the biological degradation of composite bone cement of calcium phosphate and cancellous bone granules,as well as its biophysical and solidifying characteristics.Methods The specimens of composite bone cement were determined by its solidification,which were made of 2.5g calcium phosphate cement mixed either with10%,15%,20%,25%,30%or 35%bone granules of 0.5～1.0mm diameter.The cylindrical specimens of 10mm diameter and18mm length were used for biomechnical test.Furthermore,the bone defect of 5mm?5mm?6mm in12canines were made in L 3 and L 4 verte bral body through anterolateral lumbar vertebral body approach,and composite bone cement with20%bone granules and calcium phosphate cement were filled into the bone defects respectively.The bone formation was evaluated by X-ray and histological examination.Results The composite bone cement with less than20%cancellous bone granules displayed excellent solidifying character,while with the diameter of 0.5～1.0mm and the content of 15%to20%cancellous bone granules,the maximal load and com pressive strength of the composite bone cement were of no significant difference with calcium phosphate ce ment ;but the biomech nical characteristics would decrease if the diameter was1.0～2.0mm despite of the content 15%to20%gran ules.New bone formation were observed in the center of composite bone cement 2months later,and com posite bone cement were replaced mostly by new bone at4months;while in calcium phosphate cement group,only slight degradation occurred at the interface of implant material and host bone at2and4months.Conclusion The composite bone cement of calcium phosphate with20%content and0.5～1mm di am eter of can cellous bone granules can provide the ability of rapid degradation and bone formation.The re sults of study present the basic data of the reparative materials with the composite bone cement for verte-broplasty clinically.