Hardy A E
J Med Eng Technol. 1981 Jan;5(1):30-6. doi: 10.3109/03091908109042431.
Five patients with midshaft femoral fractures treated by early cast-brace application and ambulation were studied. With the patients in lying and standing postures, force transmitted through the knee hinges, ground reaction and pressure under the thigh cast were measured each week. When standing on the injured limb, the maximum load tolerated increased as the fractures healed and ranged from 39-61% body weight and 97-100% body weight at weeks two and eight respectively. In this posture in three cases, force transmitted across the knee hinges did not exceed 35% body weight or alter significantly throughout healing, the other two reached maxima of 67 and 60% body weight at week five and values decreased to less than 50% at week ten. By week six, each patient was transmitting significant force across the fracture (31, 12, 7, 36 & 55% body weight). Vertical force on the thigh cast due to rigid soft tissue containment was calculated to be between 3.6 and 10.8 X 9.8 Newtons throughout healing in all cases. Force transmitted through the knee hinges and pressure under the thigh cast, increased linearly as the injured limb was loaded.
对5例采用早期管型支具固定并可下地行走治疗的股骨干中段骨折患者进行了研究。每周在患者仰卧位和站立位时，测量通过膝关节铰链传递的力、地面反作用力以及大腿管型下的压力。单腿站立时，随着骨折愈合，可耐受的最大负荷增加，在第2周和第8周时分别为体重的39% - 61%和97% - 100%。在这种姿势下，3例患者通过膝关节铰链传递的力在整个愈合过程中不超过体重的35%，且无显著变化，另外2例在第5周时达到体重的67%和60%的最大值，在第10周时降至50%以下。到第6周时，每位患者在骨折部位传递的力都相当可观（分别为体重的31%、12%、7%、36%和55%）。在所有病例的整个愈合过程中，由于刚性软组织固定，大腿管型上的垂直力经计算在3.6至10.8×9.8牛顿之间。随着伤肢负重，通过膝关节铰链传递的力和大腿管型下的压力呈线性增加。
