膝前交叉韧带胫骨平台止点的生物力学分析

Biomechanics Analysis Of Tibial Plateau Tip Point Of Knee Anterior Cruciate Ligament

【目的】分析前交叉韧带前内侧束和后外侧束胫骨平台止点在不同运动平面的生物力学特性,探索前交叉韧带重建胫骨平台止点的最佳位点。【方法】回顾性分析本院2010年6月至2012年10月253例行膝关节镜探查的病例的 MRI 影像,测量前交叉韧带前内侧束、后外侧束的长度、厚度、宽度及胫骨止点之前和胫骨止点之后的长度。从10具自愿捐赠的新鲜尸体上取膝关节及前交叉韧带,分析前交叉韧带不同部位的解剖特点,并行拉断试验,记录负荷-延长曲线,计算最大应变和最大应力。【结果】MRI 显示,胫骨止点将前交叉韧带分成后面2/3的长度[（22.916±2.963）mm]和前面1/3的长度[（13.096±1.759）mm]。生物动力学测试结果表明,包含胫骨止点前部位置的前内侧束的最大应力和最大应变分别为（38.843±4.152）N/mm2,（47.895±3.141）%,后外侧束的最大应力和最大应变分别为（30.260±2.242）N/mm2,（40.705±2.535）%,前内侧束的最大应力和最大应变比后外侧束的大（P ＜0.05）。【结论】包含胫骨前端的前交叉韧带前内侧束在不同运动平面为主要受力点,前交叉韧带胫骨止点前方可能为临床前交叉韧带胫骨止点重建的最佳位点。

[Objective]To analyze the biomechanical properties in different movement planes of tibial plat-eau tip point of anteromedial and posterolateral bundle of anterior cruciate ligament （ACL）and explore the op-timal tip point during tendon reconstruction.[Methods]Retrospective analyses were conducted for knee mag-netic resonance imaging （MRI）scans of 253 cases scheduled for exploration of knee arthroscopy from June 2010 to October 2012.And the parameters of length,thickness,width of anteromedial and posterolateral bun-dle of ACL and the length between posterior and anterior of tibial tip point were measured.Knees and ACLs were harvested voluntarily from 10 fresh cadaveric donors.And anatomical characteristics of different parts of ACL were analyzed.The pull-off test was performed,load-extension curve plotted and maximum strain and maximum stress calculated.[Results]MRI showed that ACL was divided by tibial tip point into posterior （2/3 of ACL）（22.91 6 ± 2.963 mm）and anterior（1/3 ACL）（13.096 ± 1.759 mm）parts.Biomechanical test showed maximum stress and maximum strain of anteromedial bundle,including anterior tibial tip point,were 38.843±4.1 52 N/mm2 and 47.895 ±3.141% and posterolateral bundle 30.260 ±2.242 N/mm2 and 40.705 ± 2.535% respectively.And maximum stress and maximum strain of anteromedial bundle were larger than those of posterolateral bundle （P 〈0.05）.[Conclusion]The anteromedial bundle of ACL,including anterior tibial tip point,is a major stress point in different movement planes.And anterior ACL tibial tip point may be an op-timal site for ACL reconstruction.