THE SIGNIFICANCE OF THE INTRAOPERATIVE CHANGE OF INTERNAL AND EXTERNAL TIBIAL ROTATION DURING COMPUTER ASSISTED ANTERIOR CRUCIATE RECONSTRUCTION

Abstract

There have been mixed reports of the contribution of the anterior cruciate ligament (ACL) to the overall envelope of tibial rotational stability. The effect of single bundle ACL reconstruction on the separate components of internal and external rotational stability respectively is also unclear.

We determined the internal and external rotation, and antero-posterior movement of the knee before and after single bundle computer assisted reconstruction of the anterior cruciate ligament (ACL) in 57 patients. The Orthopilot^® ACL (v2) software (BBraun, Aesculap) was used.

The mean overall range of tibial rotation was also significantly reduced from 30.5 degrees to 16 degrees (p< 0.0001). The mean internal rotation was significantly reduced from 16 degrees to 8 degrees (p< 0.0001). Mean external rotation was also significantly reduced from 15 degrees to 8 degrees (p< 0.0001). Unlike previous studies we did not find a greater reduction of internal rotation compared with external rotation. The mean antero-posterior movement of the tibia was significantly reduced from 12mm to 4mm (p< 0.0001).

The results of this study seem to indicate that computer assisted single bundle ACL reconstruction results in a significant intraoperative improvement in both internal and external rotatory stability as well as a significant improvement in antero-posterior stability.