Transtibial versus low anteromedial portal drilling for anterior cruciate ligament reconstruction: a radiographic study of femoral tunnel position

Abstract

Purpose: The purpose of this study is to compare femoral tunnel positions after ACL reconstruction by the transtibial (TT) approach versus the low anteromedial approach using radiographs from a single surgeon.

Methods: The standard postoperative knee radiographs of 50 patients with an ACL reconstruction were studied. Two groups were determined according to the technique used. The low anteromedial portal group and the transtibial portal group. The femoral bone tunnel was identified radiographically, and its position determined in the lateral and A-P view. Coronal and sagittal obliquity of the tunnel was measured and compared among both groups.

Results: In the sagittal plane, femoral bone tunnels averaged 54° ± 6° for the TT technique and 59° ± 12° (p = 0.07) for the low anteromedial portal technique. In the coronal plane, the bone tunnels drilled through the low anteromedial portal showed a significantly more oblique femoral tunnel position (50° ± 6°) compared to TT drilling (58° ± 9°), p ≤ 0.05.

Conclusion: Drilling the femoral tunnel through the low anteromedial portal resulted in a more oblique femoral tunnel position compared to the TT technique. Clinically, the low anteromedial portal may allow to better restore the anatomic orientation of the ACL.