Anatomical placement of double femoral tunnels in anterior cruciate ligament reconstruction: anteromedial tunnel first or posterolateral tunnel first?

PURPOSE: The purpose of this study was to know which tunnel--the anteromedial (AM) bundle or the posterolateral (PL) bundle--should be prepared first to create the 2 femoral tunnels accurately in anatomic double-bundle (DB) anterior cruciate ligament (ACL) reconstruction. METHODS: Thirty-four patients were divided into 2 groups of 17 depending on the sequence of preparation of the 2 femoral tunnels. In group A, the AM tunnel was prepared first, whereas the PL tunnel was prepared first in group P. ACL reconstruction was performed using a three-dimensional (3-D) fluoroscopy-based navigation system to place the double femoral tunnels through an accessory medial portal. The double femoral socket positioning was evaluated by 3-D computed tomography (CT) scan image. RESULTS: The non-anatomical placement of the femoral sockets occurred in 5 patients (29%) in group A, whereas the 2 sockets were placed anatomically in all patients in group P (P < 0.05). Evaluation of the AM and the PL socket location on the 3-D CT images using the quadrant method showed more similar values to the laboratory data in a literature in group P than in group A. No complication occurred in group A, whereas complications such as socket communications or back wall blowout occurred in 5 patients (29%) in group P (P < 0.05). CONCLUSION: The sequence of creating 2 femoral tunnels through accessory medial portal affected the resultant location of the sockets and the rate of the complications. When femoral tunnels are prepared with a transportal technique, PL tunnel first technique seems to be superior to AM first technique regarding anatomic placement. However, PL tunnel first technique accompanies the risk of socket communication.

Intraoperative 3-dimensional imaging-based navigation-assisted anatomic double-bundle anterior cruciate ligament reconstruction.

In anatomic double-bundle anterior cruciate ligament (ACL) reconstruction, it is more technically demanding, even for experienced surgeons, to place 2 femoral tunnels within the ACL attachment than to place 2 tibial tunnels. We describe a technique using a three-dimensional (3-D) fluoroscopy-based navigation system to place 2 femoral tunnels accurately. After a reference frame is rigidly attached to the femur, an intraoperative image of the distal femur is obtained. The image is transferred to a navigation system and reconstructed into a 3-D image. During the placement of guidewires for the femoral tunnels through an accessory medial portal, a femoral guide with a tracker feeds back to the surgeons the direction of the guidewire on the 3-D femur bone surface image in real-time. The femoral guide is placed at the center of the footprint with the aid of visual guidance of the navigation and an arthroscopic view. The flexion angle of the knee is then adjusted to prevent posterior blowout on the computer screen during insertion of the guidewire. The length of the femoral tunnel can also be estimated before overdrilling the guidewire. This technology allows surgeons to place 2 femoral tunnels precisely without any complication during anatomic double-bundle ACL reconstruction.