Tibial tunnel widening associated with anterior cruciate ligament reconstruction using autogenous hamstrings: A comparison between antero-medial portal and transtibial techniques.

OBJECTIVE: Evaluate the enlargement effect of the tibial tunnel emergence of 2 different of anterior cruciate ligament reconstruction techniques: antero-medial portal (AMP) vs. transtibial (TT) technique.

METHODS: A prospective, randomized controlled study was performed in 36 consecutive patients who underwent anterior cruciate ligament reconstruction with autologous hamstring tendon grafts employing the AMP and conventional TT techniques. Lateral and antero-posterior radiographs were obtained for each patient at 6 weeks and 12 months postoperatively. The sclerotic margins of the tibial tunnels were measured at the widest dimension of the tunnel as well as the diameter of the tibial emergence and were compared with the initially drilled tunnel size after correction for radiographic magnification. Statistical analysis was performed to compare the 2 groups by use of the independent-samples t test, with significance set at .05.

RESULTS: The mean percentage increase in the diameter of tibial tunnel emergence at 6 weeks after surgery was 8.1%±2.9 for the PAM technique and 21.20%±11.87 for the TT technique on the anteroposterior x-ray view. However, the mean percentage increase in the diameter of the tibial tunnel emergence on the lateral view was 7.1%±4.72 for the medial portal technique and 17.64%±11.48 for the transtibial technique. This difference was statistically significant on both anteroposterior and lateral views.

CONCLUSIONS: The diameter of the tibial tunnel emergence for hamstring autologous anterior cruciate ligament reconstructions was significantly lower for the medial portal technique when compared with the conventional TT technique.