At the time of surgery, a diagnostic arthroscopy was performed, with confirmation of full-thickness cartilage loss on the lateral patellar facet and lateral trochlea. A shaving chondroplasty was performed, debriding the chondromalacia back to a stable rim (Fig. 9.3a, b). Next, the open portion of the procedure was initiated. An 8 cm incision along the medial patellar edge extending to the level of the tibial tubercle was placed. An open lateral retinacular release was performed, with care taken to protect the superior lateral geniculate artery. This was able to correct the excessive lateral patellar tilt. Next, attention was turned to the tibial tubercle osteotomy. A 45° angle of osteotomy was chosen, and the distal periosteum of the osteotomy was left intact to serve as a hinge point. A correction of 1 cm of medialization and 7 mm of anteriorization was achieved to reduce the TT-TG to a desired 10 mm. Provisional clamps were placed, and tracking was checked prior to placement of two 4.5 mm bicortical screws (Fig. 9.4). The final step involved MPFL reconstruction to address the patella subluxation. Gracilis autograft was harvested in the standard fashion and prepared on the back table. The proximal medial border of the patella was dissected, and two parallel 3.2 mm tunnels were drilled from the medial border to the anterior mid-patella to allow a looped passage of the gracilis graft, leaving the free ends for attachment in the femur. Schottle’s point was identified at the junction between Blumenstadt’s line and the posterior femoral condyles, along the posterior cortical line of the femur [16] (Fig. 9.5). A guide pin was placed at the MPFL origin. Isometry was then checked with the graft around the guide pin by taking the knee through a full range of motion. After verification, final graft passage and interference screw femoral fixation was completed with the knee at 45° of flexion so that the patella was fully seated within the trochlear groove during tensioning.

Postoperatively, the patient was initially restricted to 50 % weight bearing until the osteotomy was healed (Fig. 9.6a–c). Flexion began at 0–60° and increased by 30° every 2 weeks in a hinged brace. She ultimately went on to heal uneventfully, although she continued to report occasional anterior knee pain and slight irritation related to the tibial tubercle screws, which required hardware removal at 15 months postoperative. Final radiographs prior to hardware removal are shown in Fig. 9.7a, b.