CAJ | 학술논문

目的通过生物力学及有限元分析法了解大块后踝骨折不同复位程度对胫距关节接触情况的影响. 方法选取6具成人新鲜小腿-足标本.用DDL实验机按照中立位、背屈10°和跖屈15°的不同加载力度,并通过Tek-Scan关节压敏片相关法分析正常状态、后踝骨折、1 mm台阶、2 mm台阶、1 mm间隙、2 mm间隙时,胫距关节的接触面积、接触压强和峰值压强.构建踝关节三维有限元模型,并模拟相关生物力学工况. 结果正常胫距关节中立位500 N时接触面积为(4.94 ±0.67) cm2,胫距关节的接触力度为加载力度的(83.4±2.7)％.后踝骨折固定1 mm间隙时,预设加载差异均无统计学意义;1 mm台阶时,仅跖屈15°加载时差异有统计学意义(P ＜0.05);2 mm台阶和2 mm间隙时,在多种预设加载下差异均有统计学意义(P＜0.05).有限元分析的趋势结果与相关生物力学研究一致. 结论对于大块后踝骨折应尽量解剖复位.如存在复位困难,也应该将骨折块移位控制在1 mm台阶和2 mm间隙以内,如此可基本恢复踝关节的接触协调性.
목적 통과생물역학급유한원분석법료해대괴후과골절불동복위정도대경거관절접촉정황적영향. 방법 선취6구성인신선소퇴-족표본.용DDL실험궤안조중립위、배굴10°화척굴15°적불동가재력도,병통과Tek-Scan관절압민편상관법분석정상상태、후과골절、1 mm태계、2 mm태계、1 mm간극、2 mm간극시,경거관절적접촉면적、접촉압강화봉치압강.구건과관절삼유유한원모형,병모의상관생물역학공황. 결과 정상경거관절중립위500 N시접촉면적위(4.94 ±0.67) cm2,경거관절적접촉력도위가재력도적(83.4±2.7)％.후과골절고정1 mm간극시,예설가재차이균무통계학의의;1 mm태계시,부척굴15°가재시차이유통계학의의(P ＜0.05);2 mm태계화2 mm간극시,재다충예설가재하차이균유통계학의의(P＜0.05).유한원분석적추세결과여상관생물역학연구일치. 결론 대우대괴후과골절응진량해부복위.여존재복위곤난,야응해장골절괴이위공제재1 mm태계화2 mm간극이내,여차가기본회복과관절적접촉협조성.
Objective To evaluate the effect of various reduction degrees of large posterior malleolus fracture on contact condition of the tibiotalar joint using biomechanical and finite element methods.Methods Six fresh adult cadaveric calf-foot were tested with different loadings in neutral position,10 degree of dorsiflexion,and 15 degree of plantar flexion.Models included the intact ankle and posterior malleolus fracture (not fixed,fixed with 1 mm step-off,fixed with 2 mm step-off,fixed with 1 mm gap,or fixed with 2 mm gap).Tibiotalar joint contact area,contact pressure,and peak pressure were measured using the Tek-Scan pressure sensor.In addition,a three-dimensional finite element model of the ankle joint was established and tested under the simulated biomechanical conditions.Results Mter a 500 N axial loading in the intact ankle,contact area of the tibiotalar joint was (4.94 ± 0.67) cm2 and loading strength of the tibiotalar joint was (83.4 ± 2.7) ％ of total loading strength.Contact area of the tibiotalar joint in the fracture model fixed with 1 mm gap demonstrated no significant difference in all loading conditions compared with the intact model.In 15 degree of plantar flexion,contact area of the tibiotalar joint differed between the fracture model fixed with 1 mm step-off and the intact model (P ＜ 0.05).In multiple loading conditions,contact area of the tibiotalar joint differed between the fracture models fixed with 2 mm step-off or 2 mm gap and the intact model (P ＜ 0.05).Results of finite element analysis were conformed to the related biomechanical study.Conclusions Anatomic reduction should be pursued for large posterior malleolus fracture.If difficulty exists,fracture displacement should be within 1 mm step-off and 2 mm gap so as to restore the inter-joint congruity.