Background: Traumatic rupture or laxity of the medial patellofemoral ligament (MPFL) may contribute to recurrent patellofemoral instability in active patients. MPFL reconstruction often is performed to restore patellar stability. In skeletally mature patients, MPFL reconstruction typically involves fixation of the graft at the Schottle point on the lateral aspect of the distal femur. However, in skeletally immature patients, the insertion of the MPFL is close to the open distal femoral physis, and the classic MPFL reconstruction technique is associated with a high risk of physeal injury. Therefore, physeal-sparing MPFL reconstruction is preferred in this patient population.

Purpose: This video discusses a case presentation and demonstrates the technique for physeal-sparing MPFL reconstruction in skeletally immature patients with recurrent patellar instability.

Methods: The video discusses the case presentation of a healthy, skeletally immature 13-year-old girl with recurrent left patellar instability. MRI obtained after initial dislocation revealed bone marrow edema in the medial aspect of the patella and the lateral aspect of the trochlea. An indistinct MPFL was observed, and the tibial tuberosity-trochlear groove distance was 15.5 mm. The patient experienced recurrent instability and functional limitations despite nonsurgical treatment with the use of a patellar stabilizing brace and 9 months of formal physical therapy. Therefore, surgical treatment was indicated.

The patient underwent left knee MPFL reconstruction via a physeal-sparing technique with the use of a gracilis allograft. After diagnostic arthroscopy, the medial aspect of the patella was exposed and débrided down to healthy subchondral bone to enhance tissue healing. Through a second medial femoral incision and under fluoroscopic guidance, a Beath pin was localized to the Schottle point and advanced in a slightly distal orientation. The Beath pin was then overreamed with the use of a 7-mm reamer, ensuring that it remained distal to the physis throughout the process. Femoral fixation of the gracilis allograft was achieved with the use of a 7- × 19-mm biotenodesis screw. The two limbs of the allograft were shuttled into the medial patellar exposure and secured to the patella with the use of two 3.5-mm suture anchors.

Results: At 18 months postoperatively, the patient had full knee range of motion without pain. Smooth central patellar tracking was noted, and the patella was stable to laterally directed stress. The patient was able to participate in her high school cross-country team without further episodes of instability or dislocation.

Conclusion: Optimal management of patellofemoral instability and lateral patellar dislocation in skeletally immature patients may include MPFL reconstruction via a physeal-sparing technique.