胫骨骨道定位对后交叉韧带重建“杀伤角”的影响

Effects of tiblal tunnel position on ＂killer turn＂ in posterior cruciate ligament reconstruction

目的观察胫骨骨道与胫骨平台夹角对后交叉韧带（posterior cruciate ligament，PCL）重建“杀伤角”的影响，初步探讨一种安全、合理的骨道技术。方法应用18具新鲜跟腱作为移植物在新鲜尸体胫骨侧重建PCL，所有标本骨道均采用前内侧人路，按照骨道与胫骨平台夹角不同分为A组（30°）、B组（40°）和C组（50°），每组6例。记录测试前后所有标本骨道出口面积、骨道出口压强以及在循环载荷下的循环特征。结果三组测试后胫骨骨道出口面积间差异有统计学意义（F=8．80，P〈0．05），骨道出口的压强间差异有统计学意义（F=3．91，P〈0．05）。在相同循环载荷（256N）和相同频率（126nz）作用下，三组循环次数及疲劳强度间差异有统计学意义（F=4．25，P〈0．05）。结论胫骨骨道与胫骨平台夹角与骨道出口面积及压强呈负相关，与循环载荷下的循环次数及疲劳强度呈正相关。胫骨骨道与胫骨平台成40°角的胫骨前内侧骨道为理想的骨道解剖定位。

Objective To observe the effects of different angles between tibial tunnel and tibial platform on ＂killer turn＂ in posterior cruciate ligament （PCL） reconstruction, and primarily discuss a safe and reasonable tunnel technology. Methods Eighteen fresh tendon grafts were used to recon- struct the PCL on the tibial side of fresh cadavers. The tibial tunnels of all specimens were built via an- teromedial approach. Based on the different angles between tibial tunnel and tibial platform, all speci- mens were divided into Group A （30°） , Group B （40°） and Group C （50°） , with six specimens in each group. Area of tibial tunnel exit, pressure of tibia tunnel exit and circulation characteristics of tendons un- der the cyclic load before and after biomechanical test were recorded. Results The area of tibial tunnel exit had statistical difference among three groups after the test （ F = 8.80, P 〈 0.05 ）. The pressure of tibial tunnel exit had statistical difference among three groups （ F = 3.91, P 〈 0.05 ）. The cyclic frequen- cy and fatigue strength of the transplanted tendons had statistical difference among three groups under the same cyclic load （256 N） and same frequency （126 Hz） （F=4.25, P〈0.05）. Conclusions The angle between tibial tunnel and tibial platforrn has negative correlation with the area and pressure of tibial tunnel exit, and has positive correlation with the cyclic frequency and fatigue strength of the transplanted tendons under cyclic load. The ideal anatomy position of the tibial tunnel is the anteromedial tunnel with the angle of 40° between the tibial tunnel and the tibial platform.