Intersurgeon Variance in Computer-Assisted Planning of Anterior Cruciate Ligament Reconstruction

Abstract

To test the hypothesis that computer-controlled virtual planning will prohibit tunnel malpositioning and minimize variance in tunnel placement in anterior cruciate ligament (ACL) reconstruction, thereby providing us with a more accurate and reproducible procedure. In vitro cadaver study. Three orthopaedic surgeons with different levels of experience in ACL reconstruction were asked to position tunnel placement K-wires in a predefined "optimal" position using both computer-assisted surgery (CAS) and conventional techniques in 12 fresh-frozen cadaver knees. Virtual cylindrical 8-mm grafts were virtualized as the computer system outlined an impingement area and visualized graft elongation. CAS positioning and conventional techniques were compared between surgeons and correlated to experience level. The difference in virtual planning was 5.02 mm (SD, 2.40; range, 1.77 to 9.64 mm) between the tibial tunnels and 4.61 mm (SD, 2.13; range, 2.06 to 8.42 mm) between the femoral tunnels. The mean difference between the CAS and conventional procedures was 6.20 mm (SD, 2.49; range, 3.00 to 10.39 mm) for the femoral tunnel and 6.46 mm (SD, 2.27; range, 2.65 to 10.47 mm) for the tibia tunnel. The 2 less-experienced surgeons were responsible for 3 cases of impingement when using a conventional procedure. No elongation or impingement was seen when using CAS. This cadaver study shows that computer assisted planning may reduce intersurgical variance. Computer navigation and virtual ligament reconstruction constitute a good arthroscopic surgery teaching tool. This technique enables residents and less experienced surgeons to control positioning and limit complications caused by tunnel misplacement.