胫骨后倾角与胫股关节接触力学前后移位呈线性相关：一项生物力学研究
简介
这项生物力学研究通过8具新鲜冰冻尸体膝关节，在胫骨结节下截骨后以5°为梯度将胫骨后倾角从15°调整至0°，测量不同屈膝角度及ACL完整/切断状态下的胫股接触力学变化。结果发现，无论屈膝角度和ACL完整性如何，胫骨后倾角与胫股接触力前后中心迁移呈强线性相关（r<-0.93）；减小后倾角使接触力显著前移，且ACL缺损时前移更明显。临床含义：对于复发性ACL不稳合…
英文摘要
PURPOSE: To investigate the changes in tibiofemoral contact mechanics following an infra-tubercle slope-modifying osteotomy. METHODS: An infra-tubercle slope-modifying osteotomy was performed on eight fresh-frozen cadaveric knees and fixed with an external fixator, which allowed for accurate slope adjustments from 15° to 0° in 5° increments. The specimens were axially loaded at 400 N using a custom-made, free-pivoting rig. Using a high-resolution pressure sensor, the anteroposterior and mediolateral centre of force (COF) migration and the tibiofemoral pressure characteristics, including contact area, mean pressure and peak pressure, were recorded for different tibial slope adjustments at 0°, 30°, 60° and 90° of knee flexion. These were repeated after cutting the anterior cruciate ligament (ACL). A two-way repeated measures analysis of variance was used to compare the different test conditions. Pearson's correlation and linear regression were used to analyse the relationship between tibial slope and COF migration. Statistical significance was set at p < 0.05. RESULTS: Regardless of flexion angle and ACL integrity, the tibial slope showed a strong and linear association with anteroposterior COF shift (all Pearson's r < -0.93; p < 0.01). Decreases in posterior tibial slope resulted in significant anterior translation of the COF at any flexion angle (p < 0.05). ACL deficiency further increased the anterior COF shift compared to the ACL-intact state (p < 0.05) after decreasing tibial slope. There were no significant mediolateral COF shifts or changes in contact area, mean pressure or peak pressure in the lateral and medial tibiofemoral compartments, regardless of the extent of the slope adjustment. CONCLUSION: Changing tibial slope alters the knee joint contact mechanics, with tibial slope demonstrating a strong linear correlation with anteroposterior tibiofemoral contact migration. Decreasing tibial slope redistributes the contact mechanics anteriorly, thereby unloading the posteromedial and posterolateral compartments. This further increases in cases of ACL instability and a steep posterior tibial slope. Therefore, a slope-reducing osteotomy may effectively unload frequently prematurely degenerated posterior tibiofemoral compartments in cases of recurrent ACL instability. LEVEL OF EVIDENCE: N/A.