How to handle a poorly placed femoral tunnel

Majority of primary anterior cruciate ligament reconstruction (ACLR) failures are caused by non-anatomically positioned femoral tunnels. They are predominantly anteriorly-proximally located by trans-tibial tunnel techniques for fear of posterior cortical blowout. For revision ACLR, it is important to avoid overlapping tunnels. The anatomic rectangular tunnel ACL reconstruction (ART ACLR) with a 10-mm wide bone-patellar tendon-bone (BTB) graft was developed to mimic natural fiber arrangement inside the native ACL, and to minimize space between the tunnel wall and the bone plug. As parallelepiped tunnels with a cross-sectional area of 50 mm² in ART ACLR are smaller in aperture than 10-mm cylindrical tunnels with that of 79 mm² in conventional techniques, the rectangular tunnels in revision ACLR may be less frequently compromised by non-anatomic previous tunnels. With this technique, we could more consistently create anatomically correct tunnels without tunnel-overlapping in one-stage revision ACLR. In case that the tunnel-overlapping is unavoidable, the route of over-the-top of the lateral condyle could be an acceptable option instead of the tunnel technique. Femoral tunnel malposition is a common situation in revision ACL reconstruction. Several factors must be considered prior to surgery. These include existing tunnel position, tunnel enlargement, presence of hardware, and graft selection for revision surgery. In this chapter, we will discuss the approach to femoral tunnel revision as well as techniques to handle various situations. We will also discuss our over-the-top technique and our recently described anatomical rectangular tunnel technique.