Departments of Orthopaedic Surgery and Bioengineering, Orthopaedic Robotics Laboratory, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A.; Department of Orthopaedics and Traumatology, Orthopaedics and Traumatology Sports Center, Paulista School of Medicine, Federal University of São Paulo, São Paulo, Brazil.
Departments of Orthopaedic Surgery and Bioengineering, Orthopaedic Robotics Laboratory, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A.
Arthroscopy. 2020 May;36(5):1365-1373. doi: 10.1016/j.arthro.2020.01.051. Epub 2020 Feb 11.
To quantify the effects of lateral extra-articular tenodesis (LET) on tibiofemoral compartment contact area and pressures, knee kinematics, and forces.
Nine cadaveric knees were tested using a robotic testing system. Two loading conditions, (1) anterior tibial translational load coupled with axial compression and (2) internal tibial torque coupled with axial compression, were applied for each knee state at full extension and 30°, 60°, and 90° of knee flexion. Kinematic data was recorded for 3 knee states: anterolateral capsule (ALC) competent, ALC deficient, and post-LET using a 6-mm semitendinosus graft. In situ force in the anterior cruciate ligament (ACL) was quantified using the principle of superposition by comparing the change in force measured before and after the removal of the ALC. Contact area and pressures in each tibiofemoral compartment were measured by replaying kinematics after soft tissues were removed and pressure sensors were inserted.
In response to an anterior tibial translational load, mean contact area in the medial compartment decreased by 33.1% from the ALC-competent to post-LET knee states at 90° of knee flexion (P = .042). No significant differences in lateral compartment contact pressure were found between knee states. In situ force in the ACL in response to an anterior tibial translational load decreased by 43.4% and 50% from the ALC-deficient to post-LET knee states at 60° (P = .02) and 90° (P = .006). No significant difference in kinematics was observed between the ALC-competent and post-LET knee states in each of the loading conditions at all knee flexion angles (P > .05).
In this in vitro model, LET with a semitendinosus graft did not significantly overconstrain the knee or increase pressure in the lateral compartment. Additionally, LET reduced the in situ force in the ACL in the setting of ALC injury.
The lack of knee overconstraint without significant increases in lateral compartment pressures indicates that if an LET with semitendinosus graft is not overtensioned, accelerated degenerative changes in the lateral compartment may not be expected after this procedure.
定量研究外侧关节外腱固定术（LET）对胫股关节接触面积和压力、膝关节运动学和力的影响。
使用机器人测试系统测试了 9 个尸体膝关节。每个膝关节在完全伸展和 30°、60°和 90°膝关节屈曲时，分别施加两种加载条件：（1）胫骨前向平移负荷加轴向压缩；（2）胫骨内旋扭矩加轴向压缩。记录了 3 个膝关节状态的运动学数据：前外侧囊（ALC）正常、ALC 缺失和使用 6mm 半腱肌腱移植物的后 LET。通过比较在去除 ALC 前后测量的力的变化，使用叠加原理定量测量前交叉韧带（ACL）中的原位力。在去除软组织并插入压力传感器后，回放运动学数据以测量每个胫股关节间隙的接触面积和压力。
在胫骨前向平移负荷的作用下，在 90°膝关节屈曲时，从 ALC 正常到后 LET 膝关节状态，内侧关节间隙的平均接触面积减少了 33.1%（P=0.042）。在膝关节状态之间，外侧关节间隙的接触压力没有显著差异。在胫骨前向平移负荷的作用下，ACL 的原位力从 ALC 缺失到后 LET 膝关节状态在 60°（P=0.02）和 90°（P=0.006）时分别减少了 43.4%和 50%。在每种加载条件下，在所有膝关节屈曲角度，ALC 正常和后 LET 膝关节状态之间的运动学均无显著差异（P＞0.05）。
在这个体外模型中，使用半腱肌腱移植物的 LET 并没有显著过度限制膝关节或增加外侧关节间隙的压力。此外，LET 降低了 ACL 在 ALC 损伤情况下的原位力。
如果半腱肌腱移植物的 LET 不过度紧张，且外侧关节间隙压力无显著增加，则表明该手术不会导致外侧关节间隙的退行性变化加速。
