可吸收锥形针固定手部骨折的生物力学研究

Fixationof fractures of the hand with resorbable tapered pin： a biomechanical study

目的研究可吸收锥形针的生物力学性能，探讨其在手部骨折中应用的可行性。方法取新鲜冰冻尸体掌、指骨共32根，左右配对，斜形截骨后分别用2根1．0mm克氏针和2根1．3mm可吸收锥形针固定，通过折弯试验和疲劳试验对两种材料进行生物力学测试。结果可吸收锥形针的抗弯刚度和最大载荷均显著小于克氏针；疲劳试验后两种材料的抗弯刚度差异无统计学意义，克氏针的最大载荷显著大于可吸收锥形针，而可吸收锥形针经疲劳试验后形变显著小于克氏针；疲劳试验后可吸收锥形针与克氏针的最大载荷比大于折弯试验中两者的最大载荷比，差异有统计学意义，而抗弯刚度比差异无统计学意义。结论可吸收锥形针强度小于克氏针，但足以对抗术后功能锻炼时的应力，由于具有良好的弹性，在术后功能锻炼方面比克氏针更优越。

Objective To study biomechanical characteristics of resorbable tapered pin, and to investigate the feasibility of using it for fixation of fractures of the hand. Methods Sixteen pairs of fresh frozen human cadaveric metacarpal and proximal phalangeal bones were utilized. An oblique osteotomy was made at an angle of approximately 45° to the long axis of the bone, and the bone was then fixed with two 1.0 mm K- wires or two resorbable tapered pins. Bending and fatigue testing were performed to obtain biomechanical data. Results Tne bending rigidity and the maximal load of resorbable tapered pin was significantly lower than that of K-wire. After fatigue testing, the maximal load and the displacement of resorbable tapered-pin was significantly lower than that of K-wire, while the bending rigidity is not statistically different between two materials. The maximal load ratio of resorbable tapered pin to K-wire was significantly higher after fatigue testing, but the bending rigidity ratio was not statistically different. Conclusion The rigidity of resorbable tapered pin was lower than that of K-wire, but still strong enough to counteract the stress caused by postoperative rehabilitation. Resorbable tapered pin has great flexibility and is superior to K-wire during postoperative exercise.