Meggitt B F, Juett D A, Smith J D
J Bone Joint Surg Br. 1981 Feb;63-B(1):12-23. doi: 10.1302/0301-620X.63B1.7204465.
A study was made of the mechanics of blood-bearing in a series of patients treated with a cast-brace for fracture of the distal femur. Knee hinges incorporating strain-gauges, a simple force-plate on the floor and a standardised weight-bearing test were used to record axial loads through the cast-brace itself and through the fracture during the phases of healing. The cast-brace carried loads of only 10 to 20 per cent of body weight and functioned mainly as an antibuckling hinged tube. Patterns of weight-bearing recovery showed that the fracture itself limited loads to safe levels. A measure of the recovery of strength at the fracture was determined and termed the "fracture load index". Graphs obtained in this way demonstrated four biomechanical phases of bony union which correlated well with the stages of clinical healing. The clinical application of these results have led to improvements in the design of braces and the use of a cylinder cast-brace for fractures of the distal half of the femoral shaft and of a new type of brace with a hinge at the hip attached to the thigh cast for fractures of the proximal shaft. A simple clinical test is described by which it is possible to monitor the healing of fractures in cast-braces.
对一系列采用石膏支具治疗股骨远端骨折的患者进行了血液承载力学研究。使用带有应变片的膝关节铰链、地板上的简易测力板以及标准化负重测试，来记录愈合阶段通过石膏支具本身以及骨折部位的轴向负荷。石膏支具承受的负荷仅为体重的10%至20%，主要起到抗屈曲铰链管的作用。负重恢复模式表明，骨折本身将负荷限制在安全水平。确定了骨折部位强度恢复的一个指标，并将其称为“骨折负荷指数”。通过这种方式获得的图表展示了骨愈合的四个生物力学阶段，与临床愈合阶段密切相关。这些结果在临床上的应用促使支具设计得到改进，对于股骨干远端骨折采用筒状石膏支具，对于近端骨折采用一种新型支具，该支具在髋部有铰链并与大腿石膏相连。描述了一种简单的临床测试方法，通过该方法可以监测石膏支具中骨折的愈合情况。
