[Implant-free replacement of the anterior cruciate ligament with the double bundle technique: a modification of Pässler's operation technique].

Reconstruction of the anterior cruciate ligament using the double bundle technique provides better covering of the anatomic insertion site areas and fiber length change behavior. Biomechanical studies and intraoperative measurements with computer navigation systems document increased stability in particular due to rotational stability. To date the impact of the posterolateral bundle is questioned and clinical studies have reported divergent outcomes. In favor of enhanced rotational stability, some techniques leave the basic principles of aperture or central graft fixation, decreasing primary stability and running the risk of tunnel widening especially on the femoral site. Additional use of interference screws means increased implants and costs and bone void in cases of revision is challenging. A technique for anatomic double-bundle reconstruction without the use of implants is presented, which allows for femoral aperture fixation with high primary stability of both bundles. In terms of the knot/press-fit technique of Paessler in the U-shaped tendons, a knot is created at the free end, which serves as a rigid press-fit anchoring in bottleneck shaped femoral drill holes at the insertion site of the anteromedial and posterolateral bundles. The drill holes are prepared in flexion of 110-115 degrees using common offset and target drill devices. Mersilen tapes are applied to introduce the grafts from femoral to tibial and to fix the tendons over a bony bridge on the tibial site after preconditioning. The gracilis tendon mimics the posterolateral bundle and is fixed in 20 degrees of flexion, the semi- tendinosus tendon is used for the anteromedial bundle and is fixed in 40 degrees of flexion. The advantages of the presented technique are the central, rigid femoral anchoring without hardware, the thin bone tunnels which show no tunnel widening and allow for an optimal bone tendon contact to enhance bony ingrowth. The technique is cost-efficient and provides anatomic double bundle reconstruction of the anterior cruciate ligament. The sacrifice of hardware ensures easy revisions. The disadvantages are the peripheral tibial fixation, the preparation of the tendons needs tendon length and the creation of tendon knots providing high stability requires practice. The two femoral bone tunnels have proved to be safe regarding the stability of the lateral femoral condyle.