2015 ISAKOS Biennial Congress ePoster #1331

Three-Dimensional Reconstruction Computed Tomography Evaluation of Tunnel Location and Angle During Single-Bundle Anterior Cruciate Ligament Reconstruction: A Comparison of Anteromedial Portal and Outside-In Techniques

Sang Hak Lee, MD, PhD, Seoul KOREA, REPUBLIC OF
Kyoung-Ho Yoon, MD, PhD, Prof., Seoul KOREA, REPUBLIC OF
Jong-Wook Jeon, MD, Seoul KOREA, REPUBLIC OF
Kyung Hee University Hospital at Gangdong , Seoul, KOREA

FDA Status Not Applicable

Summary: Following single bundle anatomic ACL reconstruction, 3D CT showed significantly shallower, more ellipsoidal and less acute bending angle with femoral tunnel in the AMP group than in the OI group.

Abstract:

Purpose

Tibial tunnel independent drilling has been increasing interest for anatomic ACL reconstruction in recent years. The purpose of this study is to compare the geometry and position of the femoral tunnel between the anteromedial portal (AMP) and outside-in (OI) techniques after anatomic single bundle ACL reconstruction.

Methods

We prospectively evaluated 82 patients undergoing single bundle ACL reconstruction with hamstring tendon autografts using either the AMP (n=40) or OI (n=42) technique. The location of the tibial and femoral tunnel aperture were assessed by immediate postoperative 3-dimensional computed tomography (3D CT) imaging with OsiriX imaging software. Femoral graft bending angle, femoral tunnel aperture shape (height/width ratio), femoral tunnel length and posterior wall breakage were also measured.

Results

There was no significant difference in femoral tunnel position perpendicular to the Blumensaat line. However the mean femoral tunnel position parallel to the Blumensaat line in the AMP group was significantly shallower than that in the OI group (P=0.025) There was no statistical difference between the two groups in tibial tunnel position. The mean femoral tunnel lengths did not differ between the AMP and OI group (36.1±0.33 mm, 35.6±0.37 mm, respectively; P=0.548) The AMP group (108.9°±10.2°) had a significantly more acute than those of OI group (99.6°±7.1°) (P<0.0001). The mean height/width ratio in the AMP group (1.21±0.20) was significantly more ellipsoidal than that in the OI group (1.07±0.09). Posterior wall breakage was detected in 3 cases (7.5%), which were all in AMP group.

Conclusions

Following single bundle anatomic ACL reconstruction, 3D CT showed significantly shallower femoral tunnel in the AMP group than in the OI group. The AMP group resulted more ellipsoidal femoral tunnel with risk of posterior wall breakage than the OI group. The OI group revealed a more acute bending angle in femoral tunnel than the AMP group.