Comparison of posterolateral corner reconstructions using computer-assisted navigation.

PURPOSE This study evaluated different fibular-based reconstruction techniques for grade III posterolateral corner (PLC) injuries. METHODS Seven fresh-frozen cadaveric knees were used in this study. A surgical navigation system was used to determine varus opening and external rotation at 0 degrees , 30 degrees , and 60 degrees with a 9.8-Nm varus stress and 5-Nm external rotation stress applied to the tibia. Intact and disrupted PLC knees were used as controls. Four different fibular-based reconstruction techniques were evaluated. The femoral attachments consisted of a single- or double-tunnel technique, and the fibula attachment consisted of an anteroposterior or oblique tunnel technique. RESULTS Sectioning of the PLC resulted in an increase in varus and external rotation at all flexion angles. All reconstruction techniques restored varus and external rotation stability compared with the PLC-deficient state, but the single-femoral tunnel reconstruction with an anteroposterior fibular tunnel did not restore varus or external rotation stability at 30 degrees and 60 degrees . No reconstruction technique overconstrained the knee at any flexion angle. CONCLUSIONS A double femoral tunnel with an oblique fibular tunnel best restored native knee kinematics to the lateral side of the knee. CLINICAL RELEVANCE Although there are many different techniques to reconstruct the PLC-deficient knee, this study suggests that a single-graft, fibular-based reconstruction that replicates the femoral insertions of the lateral collateral ligament and popliteus will be able to restore varus and external rotation stability to the knee.