Physeal-Sparing MPFL Reconstruction Technique With Lateral Retinaculum Lengthening.

Background: In skeletally immature patients, medial patellofemoral ligament (MPFL) reconstruction must consider the femoral physis while also trying to reproduce the ligament as anatomically as possible. There is currently no gold-standard surgical approach.

Indications: Previous surgical techniques for MPFL reconstruction in skeletally immature patients have described methods to avoid the physis, but it is difficult to accomplish this and still place the tunnel at Shottle's point. The technique described in this video allows the surgeon to find Shottle's point while still placing a tunnel that is all-epiphyseal.

Technique description: Following MPFL attachment to the patella, the guide pin is placed at Schottle's point under fluoroscopic guidance, and the scope is placed facing the posterior cruciate ligament (PCL) footprint. With the knee at 90° of flexion or greater, the guide pin is passed through the femoral condyle, aiming directly at the scope such that the pin enters the notch through the PCL footprint. The pin can then be passed anteriorly through the knee and the anterolateral soft tissues without endangering the lateral femoral condyle or the patellar tendon. A blind-ended tunnel is then drilled through the epiphysis to the level of the cortex making up the PCL footprint. Care is taken to ensure appropriate graft length such that the graft does not "bottom out" in the tunnel. The graft is passed into the tunnel and secured with an interference screw while the knee is in 45° to 60° of flexion.

Results: Expected outcomes for this all-epiphyseal MPFL reconstruction are very good. Patients begin physical therapy immediately after surgery and are allowed full weightbearing and full range of motion without a brace.

Discussion/conclusion: The MPFL attachment is very near the medial femoral physis. Due to the undulating physis, placing the start of the femoral tunnel at the femoral MPFL attachment point requires that the tunnel trajectory be directed toward the center of the knee. The technique described in this video allows for all-epiphyseal femoral tunnel drilling with a starting point at the MPFL femoral attachment, allowing the graft to be placed as anatomically as possible.

Patient consent disclosure statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.