Paavolainen P, Slätis P, Karaharju E, Holmström T
Acta Orthop Scand. 1979 Aug;50(4):369-74. doi: 10.3109/17453677908989778.
Biomechanical properties of osteotomized rabbit tibio-fibular bones fixed with 6-hole stainless steel AO/DCP plates were investigated with torsional loading 3 to 24 weeks postoperatively. During the first 9 weeks maximum torque capacity, energy absorption and torsional rigidity increased, reflecting progressive bony union between the fractured bone ends. From 9 to 24 weeks the values of torque capacity and energy absorption decreased, whereas torsional rigidity seemed to reach a steady state without further significant changes. For the three parameters considered, the mean percentage differences between the osteotomized plated bones and their paired-sham-operated controls were 69, 64 and 80 per cent, respectively. The results suggest that internal fixation of fractured bones provides conditions for undisturbed fracture healing, but that subsequently the rigid nature of the implant has an adverse effect on the cortical bone, which slowly loses strength. Thus the optimal time for removal of the plate seems to be shortly after the fracture has healed and before the bony tissue had been weakened by secondary changes, such as cancellous transformation and spatial rearrangement of the tubular bone.
对术后3至24周的兔胫腓骨截骨处用6孔不锈钢AO/DCP钢板固定后的生物力学特性进行了扭转负荷研究。在最初的9周内，最大扭矩承受能力、能量吸收和扭转刚度增加，反映出骨折断端之间逐渐形成骨愈合。从9周到24周，扭矩承受能力和能量吸收值下降，而扭转刚度似乎达到稳定状态，没有进一步显著变化。对于所考虑的三个参数，截骨钢板固定骨与其配对假手术对照之间的平均百分比差异分别为69%、64%和80%。结果表明，骨折内固定为骨折顺利愈合提供了条件，但随后植入物的刚性对皮质骨有不利影响，皮质骨强度会慢慢丧失。因此，取出钢板的最佳时间似乎是在骨折愈合后不久，且在骨组织因诸如松质骨转化和管状骨空间重排等继发性改变而变弱之前。
