桡骨远端骨折掌侧与背侧接骨板固定的生物力学比较

Biomechanical comparison of dorsal versus volar plate osteosynthesis for the dorsally unstable distal radius fracture

目的比较背侧移位桡骨远端骨折掌、背侧接骨板内固定后的生物力学性能，为桡骨远端骨折的治疗策略提供实验依据。方法取6对12块人体桡骨远端标本，制作背侧移位桡骨远端骨折模型，配对标本一侧采用接骨板掌侧内固定，另一侧采用接骨板背侧内固定，固定完成后置于材料测试机上进行轴向压缩实验，实验模式为载荷破坏实验，记录载荷一位移曲线，获得标本破坏时的载荷和骨吸收的能量，实验结果进行统计学配对处理。结果5对标本在轴向载荷下向掌侧发生成角倾斜，1对标本在轴向载荷下发生骨折端的嵌插。掌侧接骨板固定组的平均破坏载荷为[（1520．05±579．56）N，x±s，下同]，破坏时骨吸收的能量平均为（10．04±3．62）J；背侧接骨板固定组的平均破坏载荷为（1326．77±384．86）N，标本破坏时骨吸收的能量平均为（8．21±3．74）J，组间对比差异无统计学意义（P〉0．05）。结论掌侧接骨板固定是治疗桡骨远端骨折理想的固定方式。

Objective To compare the biomechanical stabihty of dorsal and volar plate osteosynthesis in the treatment of dorsally displaced distal radius fracture. Methods Six pairs cadaveric radius specimens were osteotomized at the distal region to make the dorsally displaced medeIs, then the specimens were fixed by dorsal plate osteosynthesis in one specimen （dorsal group） and by volar plate osteosynthesis in the other specimen of the same pair （volar group）. Then all the specimens were placed in the Shimazu material testing machine for axial loading till failure. The load-displacement curves were recorded, peak load and energy absorbed by the specimen at the destroying point were gathered to assess the 2 methods of fixation. Statistic analysis was run to compare results of the two groups. Results Five pairs of specimens were bended toward the volar side under axial load, 1 pair of specimens were axially compacted. The mean peak load was （ 1 326.77± 384.86） N for the dorsal group and （ 1 520.05± 579.56） N for the volar group, respectively. The energy absorbed by the specimen at the destroying point was （8.21± 3.74 ） J for the dorsal group and （ 10. 04± 3. 62 ） J for the volar group respectively. Paired-samples t-test suggested no significant difference between the 2 groups （ P 〉 0. 05 ）. Conclusion Volar plate osteosynthesis is the ideal choice for treatment of distal radius fracture.