牵引夹板治疗骨折时橡皮筋拉伸和应力松弛测试

背景：单纯石膏外固定治疗桡骨远端粉碎性骨折难以实现良好复位和固定，近年来以牵引式夹板治疗的效果较好。 目的：运用生物力学的研究方法，对比分析牵引式夹板治疗桡骨远端粉碎性骨折时橡皮筋拉伸及应力松弛与效果的关系。 方法：236例桡骨远端粉碎性骨折患者按治疗方法分为治疗组和对照组，治疗组实行牵引式夹板治疗，对照组实行单纯手法整复夹板外固定。治疗后定期拍摄X射线片观察骨折愈合情况，腕关节功能采用Dienst评估标准进行评定。采用Instron电子万能材料试验机3367对牵引的橡皮筋进行橡皮筋拉伸和应力松弛实验，测试橡皮筋的最大应力。 结果与结论：按意向性处理分析，全部进入结果分析。患者随访均超过5个月，最长随访13个月。Dienst功能评估：治疗组优68例，良42例，优良率93.2%，对照组优良率52.6%，治疗组优良率显著高于对照组。证实采用牵引式夹板治疗桡骨远端粉骨折，操作简单方便，临床疗效可靠。橡皮筋拉伸和应力松弛实验结果显示，橡皮筋的最大应力为46.97 N，最终应力保持在20.60 N，能够达到桡骨远端粉骨折复位治疗的牵引作用。

Rubber band stretching and stress relaxation tests during the treatment of fractures with traction splint

BACKGROUND:Simple plaster external fixation for the treatment of distal radius fracture is difficult to obtain the good reduction and fixation, and in recent years, traction splint has better treatment effect. OBJECTIVE:To comparatively analyze the effect of rubber band stretching and stress relaxation on the treatment of distal radius fracture with traction splint through biomechanical methods. METHODS:Totally 236 cases of distal radius comminuted fractures were divided into treatment group and control group according to the treatment method. The patients in the treatment group were treated with traction splints and the patients in the control group were treated with manipulative therapy and splints external fixation. The X-ray films were taken regularly to observe the healing of the fracture, and the wrist function was assessed with Dienst assessment standards. Instron Electronic Universal Material Testing Machine 3367 was used to detect the rubber band stretching and stress relaxation of the traction rubber band in order to test the rubber band maximum stress. RESULTS AND CONCLUSION:According to the intent-to-treat analysis, all the patients were involved in the final analysis. All the patients were followed-up for more than 5 months, and longest for 13 months. Dienst functional assessment showed in the treatment group, excellent in 68 cases, good in 42 cases and the excellent and good rate was 93.2%; the excellent and good rate of the control group was 52.6%, the excellent and good rate of the treatment group was significantly higher than that of the control group. Traction splint for the treatment of distal radius fracture has the advantages of simple operation and reliable clinical efficacy. Rubber band stretching and stress relaxation results showed that the maximum stress of the rubber band was 46.97 N and it was maintained at 20.60 N, thereby achieving the traction effect in the reduction treatment of distal radius comminuted fractures.