Brewster N T, Gillespie W J, Howie C R, Madabhushi S P, Usmani A S, Fairbairn D R
Princess Margaret Rose Orthopaedic Hospital, Edinburgh, Scotland, UK.
J Bone Joint Surg Br. 1999 Jan;81(1):118-24. doi: 10.1302/0301-620x.81b1.8480.
In impaction grafting of contained bone defects after revision joint arthroplasty the graft behaves as a friable aggregate and its resistance to complex forces depends on grading, normal load and compaction. Bone mills in current use produce a distribution of particle sizes more uniform than is desirable for maximising resistance to shear stresses. We have performed experiments in vitro using morsellised allograft bone from the femoral head which have shown that its mechanical properties improve with increasing normal load and with increasing shear strains (strain hardening). The mechanical strength also increases with increasing compaction energy, and with the addition of bioglass particles to make good the deficiency in small and very small fragments. Donor femoral heads may be milled while frozen without affecting the profile of the particle size. Osteoporotic femoral heads provide a similar grading of sizes, although fewer particles are obtained from each specimen. Our findings have implications for current practice and for the future development of materials and techniques.
在翻修关节置换术后包容性骨缺损的嵌压植骨中，移植骨表现为易碎的聚集体，其对复合力的抵抗力取决于分级、正常负荷和压实程度。目前使用的骨磨具产生的颗粒尺寸分布比使抗剪应力最大化所需的更为均匀。我们使用来自股骨头的碎异体骨进行了体外实验，结果表明其力学性能随着正常负荷的增加和剪切应变（应变硬化）的增加而改善。力学强度也随着压实能量的增加以及添加生物玻璃颗粒以弥补小颗粒和极小颗粒的不足而增加。供体股骨头可以在冷冻状态下研磨，而不会影响颗粒尺寸分布。骨质疏松的股骨头提供类似的尺寸分级，尽管每个标本获得的颗粒较少。我们的研究结果对当前的实践以及材料和技术的未来发展具有启示意义。
