The double-bundle technique for anterior cruciate ligament reconstruction: a systematic overview.

In traditional anterior cruciate ligament reconstruction, there is a subset of patients complaining of knee instability, especially rotational instability, and athletes not able to return to their preinjury level of sports activity. Currently, controversy exists over the usefulness of the double bundle technique (DBT) in addressing these problems. In order to evaluate the DBT, we completed a literature review from 1969 to February 2006 focusing on anatomy, magnetic resonance imaging, graft incorporation, biomechanics, kinematics, surgical techniques, complications and outcome. The DBT is not a standardized technique, which makes it difficult to compare results. Cadaver studies have proven biomechanical advantages with respect to ap-stability, but assessing the rotational stability remains difficult. There is a lack of available outcome studies with sufficient follow-up to demonstrate the potential advantages of DBT. The theoretical advantages of DBT require careful evaluation with outcome, biomechanical and kinematic studies. In addition, studies are needed to address issues such as graft incorporation and complications. An advantage offered by DBT is the possibility to identify rupture patterns that can lead to surgical preservation of an intact and augmentation of an injured bundle. The approach of augmentating a single bundle technique reconstruction with adequate anterior-posterior but poor rotational stability is promising.

Anatomy of the anterior cruciate ligament double bundle structure: a macroscopic evaluation.

INTRODUCTION: Traditional anterior cruciate ligament (ACL) surgery has demonstrated good results, but there is still a subset of unsatisfactory outcomes. Trends in reconstruction technique have changed from bone-patella-tendon-bone to hamstring refixation, and the next step appears to be the double bundle concept. METHODS: We examined six fresh-frozen cadaver knees to evaluate the double bundle structure, dynamic motion characteristics and the relationship of knee flexion and relative position of the femoral insertion sites of the ACL. RESULTS: In all knees, we identified an anteromedial (AM) and posterolateral (PL) bundle. The motion pattern demonstrated that the AM and PL bundles are oriented near parallel with the knee extended, and twist around each other as the knee is flexed. The visualization of the femoral footprint anatomy differs with knee flexion. DISCUSSION: The double bundle model facilitates restoration of the original footprint anatomy and biomechanics more easily than the concept of the ACL as a one-bundle structure and the use of the o'clock position. It is essential to be aware of the degree of knee flexion when drilling the femoral tunnels. PERSPECTIVE: Anatomic ACL reconstruction is a concept, not a technique, and allows a more refined surgical approach to ACL reconstruction including revision cases and partial ACL tears.