The ACL portion of the case is performed first, passing and fixing the graft on the femoral side but leaving it unfixed on the tibial side. I extend the anterior incision and protect the tibial-sided tales of the ACL graft so that we do not inadvertently cut them. First, we expose the anterolateral aspect of the knee over Gerdy‘s tubercle for the later anterolateral osteotomy. We then dissect into the retropatellar space and identify the tendon borders both on the medial and lateral sides of the patellar tendon insertion into the tibial tubercle and began our medial dissection. We elevate the MCL soft tissue sleeve that includes the pes insertion and scar from prior ACL surgery in a subperiosteal fashion and elevate the superficial MCL. I then use a Cobb elevator to dissect the sleeve further and continue posteriorly in a subperiosteal fashion to the tip of the fibular head and then I replaced the cobb with the radiolucent Hohmann retractor. I then use fluoroscopic imaging to place the first guide-pin obliquely, distal to the ACL tunnel and directed toward the tip of the fibular head. A second pin is placed in line and posterior to the first pin.

Then use the oscillating saw to cut the posterior cortex and the posterior 2/3 of the tibia to the projected location of the hinge point. I then use the adjustable wedge (and in her case 8°) to place a 3rd pin distal to the proximal pins to create a wedge resection guide to perform an anterior bone resection from the medial aspect of the tibia, then direct the pin in a parallel fashion to the proximal row of pins. I then will first make my biplanar coronal cut that will extend supratubercle while protecting the patellar tendon with an army-navy type retractor.

Then I take the oscillating saw to cut the anteromedial wedge from the medial side of the tibia by using the posterior proximal pin and distal anterior pin to guide my saw path and create the distal cut of the wedge. The wedge is then removed. I then place a lateral hinge pin to allow flexibility and protection of the lateral hinge, placing it just anterior to the fibular head and in the posterior region of the tibia to allow flexion and anterior closure of the osteotomy site later. I then insert the calibrated wedge posteromedially into the osteotomy site to correct the varus component first. Now I expose Gerdy’s tubercle by elevating the IT band insertion and proximal aspect of the anterior compartment to prepare for the anterolateral resection. Then place fluoroscopic imaging on the lateral view and use the oscillating saw parallel to the joint line proximally and measured distally according to preop planning to resect the wedge. I then use a curette to remove that wedge such that we have an anterior wedge, both laterally and medially, and then hyperextend the knee. By confirming the hinge pin bending, we are deflexing through the proximal osteotomy site and decreasing the posterior tibial slope while the medial metal calibrated wedge maintains our varus correction.

Alignment and correction of varus and posterior tibial slope are confirmed. Then bone graft is impacted into the osteotomy site and the plate is applied in a standard fashion, avoiding placement of screws into the ACL tibial tunnel. I then reinforce the anterolateral aspect of the osteotomy closure by placing a single staple, in this case a radiolucent type. The tibial post is then placed and the ACL graft is fixed to the tibia in a standard fashion. The MCL and periosteal sleeve from the medial side is then slid under the plate and secured, the IT band is repaired, the hinge pin is removed, and a layered closure is performed.