Purpose: 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.
Type of study: In vitro cadaver study.
Methods: 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.
Results: 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.
Conclusions: This cadaver study shows that computer assisted planning may reduce intersurgical variance.
Clinical relevance: 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.