In vivo knee rotational stability 2 years after double-bundle and anatomic single-bundle ACL reconstruction.

PURPOSE

The objective of this study was to evaluate knee rotational stability at least 2 years after anatomic single-bundle anterior cruciate ligament (ACL) reconstruction (SB) and double-bundle ACL reconstruction (DB) in comparison with the contralateral healthy knee joint. The Cincinnati, Lysholm and IKDC scores were analysed too.

METHODS

There were 40 patients in both groups, the mean follow-up was 27 months. For all measurements, the navigation system OrthoPilot was used. Measurement started with the patient in the standing position in neutral rotation. Then, the patient achieved in 30° knee flexion under weight-bearing maximal external trunk rotation and returned to the neutral position. The same measurement was done for the internal trunk rotation. For the anterior-posterior stability, KT-1000 arthrometer was used. All measurements were repeated three times for each knee joint.

RESULTS

After the DB reconstruction, the mean external rotation of the tibia (ER) was 8.2° and the internal rotation (IR) was 10.2°. In the contralateral healthy knee joint, ER was 8.5° (p = 0.597) and IR was 12.1° (p = 0.064). After the SB reconstruction, ER was 9.4° and IR was 13.1°. In the contralateral healthy knee joint, ER was 7.7° (p = 0.066) and IR was 9.8° (p = 0.005). Anterior-posterior translation was to the same extent for both groups.

CONCLUSIONS

The DB reconstruction of the ACL restores the rotational stability of the knee joint without any significant difference in comparison to the contralateral healthy knee (p > 0.05). The main finding of this study is that the internal rotational stability of the knee joint after the anatomic SB technique is not sufficient.