指伸肌腱终腱损伤的生物力学研究

Biomechanical study on the injury of the terminal extensor apparatus

目的 从生物力学角度探讨指伸肌腱终腱损伤的发病机理。方法 取新鲜成人尸体的示、中、环、小指各 10指 ,采用拉伸实验和冲击实验方法进行生物力学测试分析。结果 拉伸试验 :终腱的应力应变曲线表明终腱的中段是强度危险区。冲击试验 :终腱具有速度依赖性。快负荷时 ,终腱强度小于骨质 ,损伤以终腱断裂为主 ;慢负荷时 ,终腱强度大于骨质 ,损伤以终腱止点骨撕脱为主。结论 腱性和骨性锤状指的病理机制不同 ,前者以修复终腱的断裂部位为主 ,后者以重建指伸肌腱终腱的抵止点为主。

Objective To discuss the machanism of the mallet finger caused by the injury of the terminal apparatus from the viewpoint of biomechanics. Methods The tensile extension and crush experiment were done on the index fingers,the long fingers,the ring fingers and the little fingers from the fresh Chinese normal cadavers in 10 cases and the results were analysized by the biomechanical methods.Results We got the kinetic and tensile strength relation figure on the tensile extension experiment and indicated the middle part of the terminal extensor apparatus was the strength dangerous area.The crush experiment demonstrated that the terminal extersor apparatus had the dependancy on the speed:the strength of the terminal extensor apparatus was less than that of bone under the fast load, which made the rupture of the extensor tendon;the strength of the terminal extensor apparatus was greater than that of bone under the slow load,which led to the exersion fracture of the bone.Conclusions The machanisms of the mallet finger were different in the tendon rapture induced and bone fracture induced mallet fingers,the treatment methods were also different principally.