Evolving concepts in tunnel placement.

Tunnel placement in anterior cruciate ligament reconstruction has continued to evolve over time. The aim of this article is to review this evolution and comment on the senior author's current preferred technique. Initially, tunnels were dependent on the technique available, and isometry was felt to be important. Now, trying to reproduce the anatomy is preferred. Surgical technique has evolved from open surgery, with large anterior approaches, to arthroscopic two-incision outside-in techniques. After that, the evolution has led to the transtibial technique with one incision, then back to two incisions using the anteromedial portal, and finally, no incisions with the "all-inside technique." Anatomic, biomechanical, and clinical studies have shown that using the footprint as the site for tunnels restores the native anterior cruciate ligament kinematics and controls not only anteroposterior translation, but also rotational motion. Surgeons should evolve their techniques, as science does, to improve results and give better care to their patients.