The Effect of Central Anatomical Single-Bundle versus Anatomical Double-Bundle Reconstruction of the Anterior Cruciate Ligament on Knee Stability. A Clinical Study

PURPOSE OF THE STUDY A comparison of the efficacy of central anatomical single-bundle (CASB) reconstruction with that of double-bundle (DB) repair of the anterior cruciate ligament (ACL) in relation to knee stability in anteroposterior translation (APT), internal rotation (IR) and external rotation (ER) of the joint. MATERIAL AND METHODS A total of 40 patients were evaluated; 20 had ACL reconstruction by the CASB technique using hamstrings and 20 underwent DB repair surgery. The average age was 31.3 years, and the group included 22 men and 18 women with 19 right and 21 left knees. The KT-1000 test was used to assess the amount of APT in the knee and rotational deviations were measured by the Rolimeter. In the DB patients, measurements were performed before surgery (on joints with ACL injury), then after reconstruction of the anteromedial (AM) or the posterolateral (PL) bundle and subsequently after repair of both ACL bundles. The CASB patients were assessed before and after graft insertion. RESULTS The average APT value was 18.5 mm for the pre-operative knees and it fell to 8.9 mm after AM bundle reconstruction. However, when the PL bundle was inserted in the first place, the average APT value was 13.1 mm only. The average values recorded after the DB and CASB reconstructions were 6.1 mm and 9.1 mm, respectively. The average IR range of motion in the pre-operative joints was 18.6 degrees. After AM bundle reconstruction it was 13.9 degrees and after PL bundle repair it was 15.3 degrees. In DB reconstruction the average IR value achieved 10.4 degrees, and in CASB repair surgery it was 13.7 degrees. The average ER range of motion in the pre-operative joints was 17.8 degrees. After AM bundle reconstruction it was 14.5 degrees and after PL bundle repair it was 14.9 degrees. In DB reconstruction the average ER value achieved 11.4 degrees, and in CASB repair surgery it was 14.5 degrees. DISCUSSION Rotational stability of the knee after ACL reconstruction is one of the most important factors in restoring physiological kinematics of the joint after ACL injury. Since there are not many studies comparing knee rotational stability after CASB with that after DB reconstructions, the results presented here may contribute to selecting the optimal method of ACL reconstruction. CONCLUSIONS The results show that, in ACL reconstruction, the DB technique provides better stability to the knee, in both APT and rotation, than the CASB method. The latter has the same effect on knee stability as the presence of the AM bundle alone. When the PL bundle is added, knee stability, in both APT and internal/external rotation, is increased in comparison with central single-bundle ACL repair.