Summary

To compare the clinical outcomes, femoral and tibial tunnel positions (analyzed from three dimenstional computed tomography scans), and in the patients who want to have cancellous screw remove after operation, we receive written consent from them and to compare and analyze the result of MRI images and that of 2nd look arthroscopic findings of single-bundle anterior cruciate ligament reconstruction

Abstract

Purpose

To compare the clinical outcomes, femoral and tibial tunnel positions (analyzed from three dimenstional computed tomography scans), and in the patients who want to have cancellous screw remove after operation, we receive written consent from them and to compare and analyze the result of MRI images and that of 2nd look arthroscopic findings of single-bundle anterior cruciate ligament reconstruction using a modified transtibial technique and an anteromedial portal technique.

Methods

From February 2012 to May 2014, patients who underwent single-bundle anterior cruciate ligament reconstruction with a fresh-frozen Achilles tendon allograft and those with a follow-up time period of more than 12 months were included in this study. 45 patients underwent reconstruction with the modified transtibial technique (Group I) and 50 patients underwent reconstruction with the anteromedial portal technique (Group II). Clinical evaluation was determined by Lysholm knee score, International Knee Documentation Committee (IKDC), and Tengner activity scale. Stability was assessed by Lachman test, pivot-shift test, and KT-2000 arthrometer measurement. Three-dimensional computed tomography scans (3D-CT) were analyzed with the quadrant method to determine the femoral tunnel position and the Tsukada method to estimate tibial tunnel position. In the patients who want to have cancellous screw remove after operation, we receive written consent from them, MRI image and 2nd look arthroscopy was performed.

Results

Based on the functional and stability outcome, all patients showed significnat improvement after single-bundle anterior cruciate ligament reconstruction with no significant differences between Group I and II. The mean distance (t) from the posterior femoral condylar surface to the femoral tunnel center, measured parallel to the Blumensaat line, was 30.4% and 31.4% in each group. When measured perpendicular to the Blumensaat line, the mean distance (h) was 39.2% and 41.2% in each group. The mean distance from the center of the tibial tunnel to the anterior tangential line was 42.8% and 43.2% in each group, whereas the mean distance to the medial tangential line was each 47.3% and 47.8%. There was no statistically significant difference in the mean distance between two groups. The mean coronal obliquity of the femoral tunnel was 42.2° and 43.7° in each group, and the mean sagittal obliquity was each 41.7° and 42.9°. There was no statistically significant difference between the two groups. In the all cases of MRI examination, graft tendon was remained in good condition and have similar signal intensity with around normal cartiliage, based on the 2nd look arthroscopy, graft tension in Group I was normal in 31 patients, lax in 12, and partial tear in 2. In Group II, it was normal in 36, lax in 11, and partial tear in 3. In Group I, synovial coverage was good in 30 patients, average in 13, and poor in 2. In Group II, it was good in 31 patients, average in 16, and poor in 3. There was no statistically significant difference between two groups.

Conclusion

Both modified transtibial technique and anteromedial portal technique in single-bundle anterior cruciate ligament reconstruction demonstrated good clinical results and anatomic placement of the femoral tunnel.