Jia Gengxin, Guo Laiwei, Peng Bo, Liu Xiaolong, Zhang Shifeng, Wu Meng, Geng Bin, Han Hua, Xia Yayi, Teng Yuanjun
Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, China.
Orthopaedics Key Laboratory of Gansu Province, Lanzhou University Second Hospital, Lanzhou University, Lanzhou, China.
Quant Imaging Med Surg. 2023 Aug 1;13(8):5195-5206. doi: 10.21037/qims-22-1057. Epub 2023 Jun 13.
The graft bending angle created by the graft and the tibial tunnel has inevitably occurred during the transtibial posterior cruciate ligament (PCL) reconstruction. However, few studies quantitively analyzed this angle. This study aimed to (I) explore the optimal tibial tunnel placement to maximize the graft bending angle in the PCL reconstruction; (II) reveal the effect of the tibial tunnel placement on the graft bending angle.
This was an in-vitro surgical simulation study based on the three-dimensional (3D) computed tomography (CT). A total of 55 patients who took CT scanning for knee injuries were selected (April 2020 to January 2022) from the local hospital database for review. The 3D knee models were established on the Mimics software based on the knees' CT data. Using the Rhinoceros software to simulate the transtibial PCL reconstruction on the 3D CT knee model. The anteromedial and anterolateral tibial tunnel approaches were simulated with different tibial tunnel angle. The graft bending angle and tibial tunnel length (TTL) with different tibial tunnel angles were quantitively analyzed.
The graft bending angle in anterolateral approach with a 50° tibial tunnel angle was significantly greater than it in anteromedial approach with a 60° tibial tunnel angle (P<0.001). There was no difference of the graft bending angle between the anterolateral approach with a 40° tibial tunnel angle and the anteromedial approach with a 60° tibial tunnel angle (P>0.05). The graft bending angle showed a strong correlation with the tibial tunnel angle (for anteromedial approach: r=0.759, P<0.001; for anterolateral approach: r=0.702, P<0.001). The best-fit equation to calculate the graft bending angle based on the tibial tunnel angle was Y = 0.89X + 59.05 in anteromedial tibial tunnel approach (r=0.576), and was Y = 0.78X + 80.21 anterolateral tibial tunnel approach (r=0.493).
The graft bending angle and TTL will significantly increase as the tibial tunnel angle becomes greater. Maximizing the tibial tunnel angle (50° tibial tunnel angle) in the anterolateral approach could provide the greatest graft bending angle in the PCL reconstruction. No matter how the tibial tunnel angle is changed in the anteromedial approach, using anterolateral approach might reduce the killer turn effect more effectively than using anteromedial approach.
在经胫骨后交叉韧带（PCL）重建过程中，移植物与胫骨隧道形成的移植物弯曲角度不可避免地会出现。然而，很少有研究对该角度进行定量分析。本研究旨在：（I）探索在PCL重建中使移植物弯曲角度最大化的最佳胫骨隧道位置；（II）揭示胫骨隧道位置对移植物弯曲角度的影响。
这是一项基于三维（3D）计算机断层扫描（CT）的体外手术模拟研究。从当地医院数据库中选取了55例因膝关节损伤进行CT扫描的患者（2020年4月至2022年1月）进行回顾。基于膝关节的CT数据在Mimics软件上建立3D膝关节模型。使用Rhinoceros软件在3D CT膝关节模型上模拟经胫骨PCL重建。用不同的胫骨隧道角度模拟前内侧和前外侧胫骨隧道入路。对不同胫骨隧道角度下的移植物弯曲角度和胫骨隧道长度（TTL）进行定量分析。
胫骨隧道角度为50°的前外侧入路的移植物弯曲角度显著大于胫骨隧道角度为60°的前内侧入路（P<0.001）。胫骨隧道角度为40°的前外侧入路与胫骨隧道角度为60°的前内侧入路之间的移植物弯曲角度无差异（P>0.05）。移植物弯曲角度与胫骨隧道角度呈强相关性（前内侧入路：r=0.759，P<0.001；前外侧入路：r=0.702，P<0.001）。在前内侧胫骨隧道入路中，基于胫骨隧道角度计算移植物弯曲角度的最佳拟合方程为Y = 0.89X + 59.05（r=0.576），在前外侧胫骨隧道入路中为Y = 0.78X + 80.21（r=0.493）。
随着胫骨隧道角度增大，移植物弯曲角度和TTL将显著增加。在前外侧入路中使胫骨隧道角度最大化（50°胫骨隧道角度）可在PCL重建中提供最大的移植物弯曲角度。无论前内侧入路中的胫骨隧道角度如何变化，使用前外侧入路可能比使用前内侧入路更有效地减少“致命转弯效应”。
