Kouki Nagamune | PubMed Health

PubMed2007

Double-bundle ACL reconstruction can improve rotational stability.

Double-bundle anterior cruciate ligament (ACL) reconstruction reproduces anteromedial and posterolateral bundles, and thus has theoretical advantages over conventional single-bundle reconstruction in controlling rotational torque in vitro. However, its superiority in clinical practice has not been proven. We analyzed rotational stability with three reconstruction techniques in 60 consecutive patients who were randomly divided into three groups (double-bundle, anteromedial single-bundle, posterolateral single-bundle). In the reconstructive procedure, the hamstring tendon was harvested and used as a free tendon graft. Followup examinations were performed 1 year after surgery. Anteroposterior laxity of the knee was examined with a KT-1000 arthrometer, whereas rotatory instability, as elicited by the pivot shift test, was assessed using a new measurement system incorporating three-dimensional electromagnetic sensors. Routine clinical evaluations, including KT examination, demonstrated no differences among the three groups. However, using the new measurement system, patients with double-bundle ACL reconstruction showed better pivot shift control of complex instability than patients with anteromedial and posterolateral single-bundle reconstruction.

Adolescent↗

PubMed2006

The effect of graft tensioning in anatomic 2-bundle ACL reconstruction on knee joint kinematics.

Recently, double bundle ACL reconstruction, in which the two bundles thought to have different effects on knee kinematics are reconstructed separately, is widely believed to more favorably restore normal knee kinematics than conventional single bundle ACL reconstruction. However, rotational kinematics during physiological movement after double bundle reconstruction has rarely been tested. The purpose of this study was to measure the kinematics of the ACL deficient and reconstructed knees using two different tensioning conditions in double bundle reconstruction, and to examine the effects of each graft on knee kinematics. Six cadaveric knees were used. Six degrees-of-freedom of knee kinematics and the tension of each graft were monitored during simulated knee extension with the ACL intact, resected, and reconstructed under two different tensioning conditions: 50 N on anteromedial bundle and 0 N on posterolateral bundle (AM-favored condition); 0 N on anteromedial bundle and 50 N on posterolateral bundle (PL-favored condition). Tibial translation: After ACL reconstruction, the tibia overcorrected posteriorly in both conditions. Such an overcorrection in the AM-favored condition was larger than in the PL-favored condition. Tibial rotation: The tibia was significantly externally rotated after ACL reconstruction at a low flexion angle in both conditions. However, at a high flexion angle, tibial external rotation was shown only in the AM-favored condition. Graft tension: While total tensions were similar between the two conditions, the AM bundle shared more tension in the AM-favored condition than in the PL-favored condition. A total of 50 N of tension force was assumed to be excessive for normalizing knee kinematics at a low flexion angle even if double bundle reconstruction was used. Additionally, the AM-favored tensioning reconstruction made the tibia rotate externally and translate posteriorly even at a high flexion angle. Further research is needed to normalize knee kinematics after ACL reconstruction, however it is recommended that a moderate tensioning force is applied to the PL bundle and a minimal tensioning force to the AM bundle in double bundle reconstruction to obtain better knee kinematics.

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