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

Abstract

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° for group I and 30.0° for group II (P =.23); C) 23.9° for group I and 32.0° 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.