Finite Element Analysis of the Biomechanical Effects of 3 Posterolateral Corner Reconstruction Techniques for the Knee Joint.

PURPOSE

To compare the forces exerted on the cruciate ligaments and the contact stresses on the tibiofemoral (TF) and patellofemoral (PF) joints with respect to 3 different tibial- and fibular-based posterolateral corner (PLC) reconstructions under dynamic loading conditions.

METHODS

A subject-specific finite element knee model was developed by using 3-dimensional anatomic data from motion captures in gait and squat activities, including in vivo knee joint kinematics and muscle forces for the single subject. Cruciate ligament forces and contact stresses on the TF and PF joints under 3 PLC reconstruction techniques (tibial-based, TBR; modified fibular-based, mFBR; conventional fibular-based, cFBR) and PLC-deficient models were compared with those of the intact model in gait and squat loading conditions.

RESULTS

The cruciate ligament forces in the 3 surgical models differed from those in the intact model. The greatest differences in ligament forces from the intact model were found in the cFBR model, whereas there were no remarkable differences between the TBR and mFBR models in both gait and squat loading conditions. Contact stresses on the lateral TF and PF joints of the 3 surgical models were greater than those of the intact model under the squat loading condition.

CONCLUSIONS

The biomechanical effects achieved using the anatomic reconstruction technique were found to be improved compared with those using nonanatomic reconstruction techniques. However, the ligament forces and contact stresses under normal conditions could not be restored through any of the 3 techniques.

CLINICAL RELEVANCE

Anatomic TBR and FBR for grade III PLC injuries could restore better biomechanics in the knee joint compared with nonanatomic reconstruction. However, discrepancy with the normal condition requires further modification of surgical techniques.