Biomet ToggleLoc

Anterior Cruciate Ligament Soft Tissue Femoral Cortical Fixation: Ziploop Technology

The Biomet ToggleLoc fixation device (Warsaw, IN) relies on strong cortical suspensory stabilization for femoral fixation in anterior cruciate ligament (ACL) reconstruction. This technology has the advantage of cortical fixation combined with ZipLoop technology to increase graft-to-tunnel contact area to improve stabilization and incorporation. This technique can be used in anteromedial (AM) or transtibial portal ACL reconstruction, as well as double bundle. It uses very minimal instrumentation and is a simple technique for both bone plug and soft tissue grafts. The variation in patient anatomy and tunnel length does not change the implant; therefore only one size implant is necessary.

The ZipLoop is made of a unique weave of braided polyethylene that is woven through itself twice in opposite directions. This technology is resistant to slippage without tying knots while maximizing graft-to-tunnel interface. It also allows the graft to be tensioned after tibial fixation has been achieved.

The AM portal technique for a single-bundle soft tissue graft will be described later. The general technique can be applied to a variety of arthroscopic ACL reconstructions.

Two standard arthroscopic portals are established at the level of the inferior pole of the patella. The lateral portal is made just lateral to the patellar tendon while the AM portal is placed 1 cm medial to the medial edge of the patellar tendon. A diagnostic arthroscopy is completed, and intra-articular pathology is addressed. After this, the notch is débrided and the femoral footprint is cleared of soft tissue. The tibial footprint is identified, and a standard tibial tunnel is prepared with a reamer of appropriate size. A tibial tunnel plug is then placed, which will allow placement of a shaver into the notch to evacuate bone debris during femoral tunnel preparation.

Technique

Step 1

Prepare the femoral footprint, and estimate the center of femoral tunnel and mark with a microfracture awl ( Fig. 68.1 ).

Step 2

Place the appropriate sized over-the-top guide in the notch as the knee is brought into hyperflexion. Pass a Beath pin from the AM portal through the over-the-top guide and out the far cortex but not out the skin ( Fig. 68.2 ).

Step 3

Remove the over-the-top guide and drill bicortical with the 4.5-mm cannulated Biomet ToggleLoc drill bit ( Fig. 68.3 ).

Step 4

Remove the 4.5-mm drill bit and Beath pin. Measure your femoral tunnel length, and record this measurement ( Fig. 68.4 ).

Step 5

Place the Beath pin back in the femoral tunnel. Prepare the femoral tunnel with a cannulated acorn reamer of appropriate size. The depth is surgeon preference and can be safely determined because the femoral tunnel length is recorded from step 4. Leave at least 6 mm of bone from the femoral tunnel to the lateral cortex. Record the femoral socket depth ( Fig. 68.5 ).

Step 6

Remove the acorn reamer, and use a shaver to remove bone debris from the notch and femoral socket. Place a passing stitch on the Beath pin, and pass this through the femoral tunnel ( Fig. 68.6 ).

Step 7

Retrieve the passing stitch through the tibial tunnel ( Fig. 68.7 ).

Step 8

Pass the graft into the double strands of the ZipLoop, and mark the graft to correspond to the femoral socket depth ( Fig. 68.8 ).

Step 9

Mark the Zip suture to correspond to the femoral tunnel length. Color the Zip suture distal to this mark. This will help to identify the Zip suture from the loops around the graft. The unmarked portion corresponds to the femoral tunnel length ( Fig. 68.9 ).