Tunnel malposition is one of the most common technical reasons for anterior cruciate ligament reconstruction failure. Small changes in tunnel placement can result in significant differences in outcome. More anatomic placement of the tunnels can lead to greater knee stability and a more accurate reproduction of native knee kinematics. This Technical Note describes 2 tibial tunnel–independent methods to obtain anatomic femoral tunnel placement. The all-inside anteromedial portal technique requires only minimal surgical incisions but allows precise femoral tunnel placement. However, hyperflexion of the knee is required, adequate surgical assistance is necessary, and this technique may be susceptible to graft-tunnel mismatch. The outside-in technique may be more beneficial in obese patients, skeletally immature patients, or revision cases. On the downside, it does require an additional 2-cm surgical incision. This article also provides surgical pearls to fine-tune tibial tunnel placement.
Digital Object Identifier (DOI)
Burnham, Jeremy M.; Malempati, Chaitu S.; Carpiaux, Aaron; Ireland, Mary Lloyd; and Johnson, Darren L., "Anatomic Femoral and Tibial Tunnel Placement During Anterior Cruciate Ligament Reconstruction: Anteromedial Portal All-Inside and Outside-In Techniques" (2017). Orthopaedic Surgery and Sports Medicine Faculty Publications. 15.
Video 1. Technique of anatomic anterior cruciate ligament reconstruction. The all-inside method and inside-out method of femoral tunnel reaming are described, as is the method of anatomic tibial tunnel placement. Relevant anatomic landmarks are described, and the crucial points of each step are shown. A 45° microfracture awl is inserted through the accessory anteromedial portal to mark the preferred centrum of the femoral insertion (00:25). An Acufex Pinpoint single-bundle femoral guide can be used to visualize the diameter of the planned femoral tunnel at the native footprint (01:43). A guide pin is advanced in a lateral-to-medial direction through the aiming arm and bullet until it protrudes into the notch (01:54). A 2.4-mm tibial guide pin is advanced through the guide until the tip is visible protruding through the tibial footprint (03:03). The guide pin is set in place by advancing it forward until it docks in the roof of the femoral notch (03:24). The tibial tunnel is drilled sequentially, starting with a 6.5- or 7-mm tibial drill and increasing in size by 2- to 2.5-mm increments (03:32).