Under general (including complete muscular relaxation for secure hamstring tendons harvest) or spinal anesthesia, the patient is placed supine with both lower extremities in a straight position. A lateral thigh pillar is used for stabilization of the knee flexed to 90 and 130 degrees. A nonsterile tourniquet at 250 to 300 mm Hg is routinely applied in the most proximal part of the thigh.

In addition to a standard high anterolateral camera and standard anteromedial instrument portal, a secondary accessory anteromedial instrument portal is established 1.5 cm medially to the primary anteromedial portal. For correct placement of this accessory portal, a needle may be utilized for control of the optimal direction angle for later positioning of the femoral posterolateral bundle tunnel. Both anteromedial portals should be directly superior to the basis of the medial meniscus.

In cases of clinically unambiguous diagnosis of an ACL rupture, harvesting of the autologous hamstring tendons is performed prior diagnostic arthroscopy. In rare ambiguous cases, the diagnostic arthroscopy is accomplished in advance of the tendon harvest for detailed assurance of the rupture extension, for example, in potential partial ACL ruptures. Usually, both the larger semitendinosus and the smaller gracilis tendon were harvested for reconstruction of the anteromedial and the posterolateral bundles of the ACL, respectively. Alternatively, only the semitendinosus tendon may be utilized for reconstruction of both bundles if the length of the harvested tendon exceeds 28 cm.

In detail, an oblique transversal incision of 3 cm over the anserine pes is performed. The superficial anserine pes is cut in the direction of the collagen fibers following digital palpation of the semitendinosus and gracilis tendon. The identified tendons were secured by suture loop retention. The semitendinosus alone or both tendons were mobilized by release of soft tissue collaterals as well as adhesions and finally detached at their tibial insertion site. The ultimate harvesting of each tendon is accomplished using adequately sized tendon strippers (Arthrex, Naples, Florida).

At the back table, the muscle tissue of the harvested tendons is removed, and overlapping stitches of nonabsorbable sutures (e.g., Ethibond, Ethicon, Norderstedt, Germany) or absorbable sutures (e.g., Vicryl, Ethicon, Norderstedt, Germany) are applied at both ends of the tendons. Usually, the double-strand semitendinosus and the double-strand gracilis tendon graft measure 6 to 8 mm and 5 to 6 mm in diameter, respectively. If the diameter of one tendon graft is less than the aforementioned size, a triple-strand graft preparation is performed. Each graft is marked at 25 mm on the loop site. In cases of a single tendon harvest (semitendinosus), the minimally acceptable length of the double-looped graft is 8 cm for both the anteromedial and the posterolateral bundles.

Following standard diagnostic arthroscopy of all three compartments, concomitant intra-articular pathologies (meniscal lesions, cartilage defects) are addressed prior to reconstruction of the ACL.

The femoral dimensions of the footprint of the anteromedial and the posterolateral bundles at the intercondylar notch are identified and evaluated including mechanical probing since anatomical variations of the ACL and partial ACL ruptures may be present. Then, the torn and/or insufficient parts of the ACL are arthroscopically removed by sufficient exposure of the lateral femoral notch including their posterior osseous border and by preserving the tibial stump of the ACL due to its proprioceptive and vascular function. Usually, a notchplasty is not necessary in cases of later correct femoral and tibial tunnel positioning.

On the femoral site, the tunnel for the anteromedial bundle is drilled first using mostly a 4-mm offset drill guide (Arthrex, Naples, Florida) via the anteromedial portal. In detail, the drill guide is placed at the posterior aspect of the notch at the 1:30 o’clock (left knee) or the 10:30 o’clock position (right knee) with respect to the coronal plane. The guide wire is positioned in 130 degrees of flexion and then overdrilled by an acorn drill of the corresponding graft size to a depth of at least 25 mm. A bony bridge of 1 mm between the posterior wall of the anteromedial tunnel to the posterior cortex of the notch should be preserved for avoidance of later tunnel blowout. An osseous notch is created in both femoral tunnels using a notching device (Arthrex, Naples, Florida) at the anterior-superior edge of the tunnels for aperture fixation by bioabsorbable interference screws (Fig. 29.1).

In contrast, the femoral tunnel for the posterolateral bundle is drilled through the accessory anteromedial portal. Therefore, a modified 4-mm offset drill guide is placed in the anterior-inferior aspect of the alreadyestablished femoral tunnel aperture for the anteromedial bundle representing a 2:30 o’clock in the left or a 9:30 o’clock position in the right knee for the posterolateral bundle. This posterolateral tunnel placement is performed in 90 degrees of flexion to preserve the peroneal nerve and the chondral surface of the lateral femoral condyle from iatrogenic damage. Then, the guide wire is overdrilled with an acorn drill of the corresponding graft size as well to a depth of 25 mm. This technical aspect allows a bony bridge of approximately 1 mm between both femoral tunnels (Fig. 29.2). The divergence of both femoral tunnels permits additional stability
of the bone bridge, which is accomplished by separate anteromedial portal utilization for each femoral tunnel placement. These notches reduce drive failure and screw breakage by decreasing peak screw insertion torque. A Fiberwire and a Tigerwire 2 (Arthrex, Naples, Florida) are pulled through the femoral tunnels of the anteromedial and the posterolateral bundles via standard anteromedial and accessory anteromedial portal, respectively.