Cogent Medicine (Jan 2018)

Topographic study of the isometry testing in anatomic reconstructions of the anterior cruciate ligament of the knee

  • Joao Gabriel Villardi,
  • Alfredo Villardi,
  • Leonardo Antunes Bellot de Souza,
  • Yonder Archanjo Ching San Junior,
  • Max Ramos

DOI
https://doi.org/10.1080/2331205X.2018.1470067
Journal volume & issue
Vol. 5, no. 1

Abstract

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Purpose was to describe the perioperative isometry testing in anatomic reconstructions of the anterior cruciate ligament of the knee (ACL) using a single-bundle technique (MAXTEST). Anatomic ACL transtibial tunnel reconstruction was performed in 16 human cadaver knees. To assess the isometry, the length of Ethibond 2 ® suture thread passed through the tibial tunnel and attached to a guidewire placed at the estimated center point of the original ACL footprint on the lateral femoral condyle was measured one centimeter from the external tibial tunnel exit in the knee maximal 26 flexion and extension. The femoral entrance was modified before the perforation of the femoral tunnel to an anterior or posterior position until an isometric behaviour was observed. We called this assessment the MAXTEST. The obtained measurements were statistically analyzed. Additionally, a correlation test was conducted between the following: (1) the height from the guidewire exit point to the anterior surface of the lateral femoral condyle and the anteroposterior diameter of the lateral femoral condyle; (2) the distance from the articular surface of the tibia to the intercondylar roof and the distance between the guidewire and the intercondylar roof. The performed statistical analysis showed that the anatomic reconstruction pattern could be isometric (p-value=0.654). A linear positive correlation was found between the height from the guidewire exit point to the anterior surface of the lateral femoral condyle and the anteroposterior diameter of the lateral femoral condyle (R2=0.677, multiple R=0.823, adjusted R2=-1.154, standard error=2.72). Additionally, a positive correlation was observed between the distance from the articular surface of the tibia to the intercondylar roof and the distance between the guidewire and the intercondylar roof (R2=0.96, multiple R=0.98, adjusted R2=-1.143, standard error=0.319). We concluded that “MAXTEST” is a reproducible isometry test in anatomic single- bundle ACL reconstructions when performed before the femoral tunnel perforation.

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