Beppu M
Nihon Seikeigeka Gakkai Zasshi. 1979 Dec;53(12):1791-806.
The plating method for bone fractures is in wide use. The author studied both new bone formation and bone atrophy of the cortex of fracture site after long periods of plating. This study is concerned with the bone strength of the fracture site as influenced by rigid plate fixation, and also with bone union after the removal of the plate. The experimental results, using mature rabbits as subjects, showed the following: X-rays of the bone union at the fracture site treated by the plating method confirmed evident union at 8 weeks after surgery. The bone strength at the region of this union, as tested by the bending method (an Instron Type Testing Machine was used), showed its highest values at 28 weeks after surgery. Yet, this was only 60% of the bone strength as measured at a non-fracture site; it then gradually declined in strength. On the other hand, in the case where the plate had been removed 8 weeks after surgery, bone strength was recovered to the same level as that of non-fracture sites 16 weeks after surgery. In conclusion, rigid plate fixation for a long period may result not only in progressive bone atrophy of the cortex but also in a delayed remodeling of the bone at the region of the bone union. It is, therefore, very important to remove the plate as early as possible once union has been achieved. Careful observation, however, is necessary during the short time between plate removal and the period when bone strength becomes again normal.
骨折的钢板固定方法应用广泛。作者研究了长期使用钢板固定后骨折部位皮质骨的新骨形成和骨萎缩情况。本研究关注刚性钢板固定对骨折部位骨强度的影响，以及钢板取出后的骨愈合情况。以成年兔子为实验对象的实验结果如下：采用钢板固定法治疗的骨折部位，术后8周的X线检查证实骨愈合明显。用弯曲法（使用英斯特朗型试验机）测试该愈合部位的骨强度，术后28周时达到最高值。然而，这仅为非骨折部位所测骨强度的60%，随后强度逐渐下降。另一方面，术后8周取出钢板的情况，术后16周骨强度恢复到与非骨折部位相同的水平。总之，长期的刚性钢板固定不仅可能导致皮质骨渐进性骨萎缩，还会使骨愈合部位的骨重塑延迟。因此，一旦实现骨愈合，尽早取出钢板非常重要。然而，在取出钢板后到骨强度再次恢复正常的这段短时间内，需要仔细观察。
