Preparation for Arthroscopic Surgery

Surgery is performed with an air tourniquet in the standard supine position. An approximately 3-cm-long oblique incision is made in the anteromedial portion of the proximal tibia. The semitendinosus and gracilis tendons are harvested using a tendon stripper in the figure-four knee position. When the semitendinosus tendon is thick and long enough, the gracilis tendon is not harvested. At the beginning of arthroscopic surgery, a surgeon sits beside the knee joint of the patient. An edge of a drape is attached to a lumbar portion of the surgeon so that the patient’s leg hanging beside the table can be put on the surgeon’s knee in a sterile condition. This setup allows the surgeon to control the patient’s knee position using the surgeon’s own knee. An arthroscope is inserted through the lateral infrapatellar portal. After a routine arthroscopic examination, a remnant of the torn ACL is resected, leaving 1-mm-long ligament tissue at the femoral and tibial insertions, which can be used as landmarks for inserting guidewires.

Creation of Tibial Tunnels

In ACL reconstruction procedures with the transtibial tunnel technique, the greatest key to success is to create a tibial tunnel with an appropriate three-dimensional (3D) direction. In other words, a tibial tunnel should be created so that a guidewire for femoral tunnel creation can be easily inserted at a targeted point on the lateral condyle through the tibial tunnel. To create such a tibial tunnel, we use a specially designed wire guide, called a wire navigator (Fig. 22-1, A), which was developed in our previous study.^7,8 This device is composed of a navi-tip and a wire sleeve. The navi-tip consists of sharp tibial and femoral indicators. The axis of the wire sleeve passes through the tip of the tibial indicator (Fig. 22-1, B). First, a tibial tunnel for the PLB is created. The navi-tip is introduced into the joint cavity through the medial infrapatellar portal. The surgeon holds the tibia at 90 degrees of knee flexion, keeping the femur horizontal. The tibial indicator of the navi-tip is placed at the center of the PLB footprint on the tibia, which is located at the most posterior aspect of the area between the tibial eminences and 5 mm anterior to the posterior cruciate ligament (Fig. 22-2). Keeping the tibial indicator on this point, we aim the femoral indicator at the center of the PLB footprint on the femur (Fig. 22-3, A), which is precisely explained in the next section, and the proximal end of the extraarticularly located wire sleeve is fixed on the anteromedial aspect of the tibia through the skin incision made for the graft harvest. The proximal end and the direction of the wire sleeve are automatically determined depending on the direction of the intraarticular navi-tip (see Fig. 22-1, B). A Kirschner wire of 2 mm in diameter is drilled through the sleeve in the tibia. According to our basic studies, this tunnel does not injure this ligament because the insertion point of the wire on the anteromedial aspect of the tibia is located several millimeters anterior to the medial collateral ligament.⁴ The first tunnel is made with an approximately 6-mm cannulated drill corresponding to the measured diameter of the prepared substitute.

Fig. 22-1 The wire navigator (A) and the concept of wire navigation for the tibia (B). The wire navigator is composed of a navi-tip (A) and a wire sleeve (B). The navi-tip consists of the tibial indicator (C) and femoral indicator (D). The axis of the wire sleeve is passed through the tip of the tibial indicator. Keeping the tibial indicator at the targeted point on the tibia, we aim the femoral indicator at the targeted point (TP) on the femur. Subsequently, the direction and the insertion point of the wire are automatically determined.

Fig. 22-2 Two tibial tunnel outlets are shown. They are created at the center of the normal attachment of the anteromedial bundle (AMB) and posterolateral bundle (PLB).

Fig. 22-3 The navi-tip of the wire navigator in an arthroscopic visual field. First (A), keeping the tibial indicator at the center of the posterolateral bundle (PLB) footprint on the tibia, a surgeon aims the femoral indicator at the center of the PLB footprint on the femur. Then (B), keeping the tibial indicator at the center of the anteromedial bundle (AMB) footprint on the tibia, a surgeon aims the femoral indicator at the center of the AMB footprint on the femur.

Next, a Kirschner wire for the AMB reconstruction is drilled using the same wire navigator. The tibial indicator is placed at the center of the tibial footprint of the AMB, which is located at a point approximately 7 mm anterior to the center of the first tunnel (see Fig. 22-2). Keeping the tibial indicator on this point, we then aim the femoral indicator at the center of the femoral footprint of the AMB (Fig. 22-3, B). The wire sleeve is fixed on the anteromedial cortex of the tibia. A Kirschner wire is then drilled through the sleeve in the tibia. The knee should be extended to ensure that the tip of the second wire is located at a point 5 mm posterior to the anterior edge of the roof in the intercondylar notch. The second tunnel is drilled with an approximately 7-mm cannulated drill corresponding to the measured diameter of the prepared substitute. Subsequently, two intraarticular outlets are aligned in the sagittal plane (see Fig. 22-2).

Creation of Femoral Tunnels

In the anatomical double-bundle procedure, it is essential to precisely understand the attachment of the main ACL fibers that should be reconstructed in ACL reconstruction. Although the normal ACL has a wide footprint on the lateral condyle,^9–11 the author has found that the main ACL fiber attachment that should be reconstructed in ACL reconstruction is in the form of an egg, with its long axis inclined toward the posterior direction by 30 degrees to the long axis of the femur on the medial surface of the lateral femoral condyle⁴ (Fig. 22-4).

Fig. 22-4 Attachment of the anterior cruciate ligament (ACL) on the femur. The dotted lines show the attachment of the main fibers of the ACL. When we drew a vertical line (VL) through the contact point (C)

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