Positioning of the femoral tunnel for arthroscopic reconstruction of the anterior cruciate ligament: comparative study of 2 techniques.

OBJECTIVE To compare the accuracy of positioning of the femoral tunnel in reconstructing the anterior cruciate ligament by means of 2 techniques: tibial tunnel and anteromedial portal. METHOD Femoral tunnels were drilled in 20 knees from human cadavers by means of arthroscopy. Group I had the femoral tunnel drilled via a trans-tibial tunnel, and Group II via the anteromedial portal. Four variables were measured: A) posterior wall thickness; B) tunnel positioning at the notch; C) tunnel inclination in relation to the femoral axis; and D) distance between the wire guide exit and the lateral epicondyle. RESULTS As above, respectively, A) 2.23 mm for group I and 2.36 mm for group II (P =.54); B) 25.5 degrees for group I and 30.0 degrees for group II (P =.23); C) 23.9 degrees for group I and 32.0 degrees for group II (P =.02); D) 7.8 cm for group I and 3.9 cm for group II (P <.001). CONCLUSIONS Both techniques achieved the desired positioning for the femoral tunnel entrance and satisfactory thickness for the posterior cortex. Drilling via the anteromedial portal may provide greater protection against rupture of the posterior wall.