Accuracy in Tunnel Placement for ACL Reconstruction. Comparison of Traditional Arthroscopic and Computer-Assisted Navigation Techniques

Abstract

The purpose of this randomized, prospective study was to compare accuracy in tunnel placement as performed with a traditional arthroscopic anterior cruciate ligament (ACL) reconstruction technique and with KneeNavTM ACL, a computer-assisted surgical navigation technique. Two surgeons experienced in ACL reconstruction, but inexperienced in computer-assisted surgical navigation technique, each randomly used traditional arthroscopic guides or KneeNavTM ACL to drill a tunnel in twenty identical foam knees. Placement of the resulting tibial and femoral tunnels was measured with a computer-assisted digitizing method and compared to traditional biplanar radiographs. Statistical analysis with Student's t-test was used to compare the distance from the ideal tunnel placement to the femoral and tibial tunnels. Accuracy of tunnel placement with KneeNavTM ACL was significantly better than that obtained with the traditional arthroscopic technique. Distances from the ideal tunnel placement to the femoral and tibial tunnels were 4.2 +/- 1.8 mm (mean +/- SD) and 4.9 +/- 2.3 mm, respectively, for the traditional arthroscopic technique, and 2.7 +/- 1.9 mm (femur) and 3.4 +/- 2.3 mm (tibia) for KneeNavTM ACL. These differences were statistically different. Tunnel placement for ACL reconstruction with KneeNavTM ACL, an image-based, computer-assisted surgical navigation device with a simple and intuitive interface, was more accurate than with the traditional arthroscopic technique.

Development of a femoral template for computer-assisted tunnel placement in anatomical double-bundle ACL reconstruction

“…These results were comparable with those from several other studies which have quantified the accuracy or precision of ACL navigation systems [40,[43][44][45]. However, the measurements in three of those studies only compared the position of the preoperatively planned tunnels with the postoperative results, not with the actual position of the anatomical insertion centers; two of the studies [43,44] used sawbones, and one [45] used cadaveric knees. Musahl et al [42] defined the accuracy and precision of preoperative tunnel planning with an active robotic system in relation to a tunnel placed in the actual femoral ACL insertion, the values being 1.3 mm (mean) and 1.0 (SD), respectively.…”

“…The reported precision is similar to our own result, while the accuracy seems superior. However, the system also showed a deviation of 1.3 mm between preoperatively planned tunnels and postoperative results [45].…”

“…Various methods, from conventional guiding instruments to computer navigation and robotic systems, have been developed to help the surgeon position tunnel entrances at the desired location, mostly based on isometry or prevention of notch impingement [38]. The use of computer-assisted systems for femoral tunnel positioning during ACL reconstructions has been shown to improve accuracy [44][45][46][47].…”

“…Passive computer-assisted navigation and active roboticassisted surgery systems can contribute to minimizing variation in graft placement. The initial reports on the use of these innovative systems in ACL reconstruction have provided clear evidence that more exact bone tunnel placement relative to the preferred position can be achieved with both passive and active systems than with conventional techniques [40,41,[44][45][46][47].…”

Application of a computerised navigation technique to assist arthroscopic anterior cruciate ligament reconstruction

“…In the published orthopaedic literature, computer-assisted surgery has been reported to raise the accuracy of tunnel placement and reduce the rate of revision surgery. Picard et al [21] presented a randomised prospective study comparing the accuracy of tunnel placement performed using a traditional arthroscopic ACL reconstruction technique and a surgical navigation technique. Two experienced surgeons in ACL reconstruction randomly used traditional arthroscopic guides or navigated assisted guides to drill a tunnel in 20 identical foam knees.…”