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Medial Patellar Subluxation: Diagnosis and Treatment with Lateral Patellofemoral Ligament Reconstruction

February 10, 2018

Contributors: David A Shneider, MD; Michael G Saper, DO, ATC; Michael G Saper, DO, ATC

This video demonstrates lateral patellofemoral ligament (LPFL) reconstruction for the management of medial patellar subluxation. Medial patellar subluxation is a poorly recognized clinical condition characterized by chronic anterior knee pain that is exacerbated with knee flexion. Medial patellar subluxation was first described as a complication after lateral retinacular release; however, multiple cases of iatrogenic, traumatic, and isolated medial subluxation have been reported. With the knee in full knee extension during arthroscopy, lateral laxity and medial tilt of the patella can be identified. As the knee is flexed to 30°, the patella moves medially and may subluxate over the edge of the medial facet of the trochlea. LPFL reconstruction is performed using a partial-thickness quadriceps tendon graft without bone tunnels, screws, or anchors in the patella. The graft is taken from the most superficial layer of the tendon, leaving its patellar insertion intact. Using a clamp, a subfascial tunnel is created in the lateral retinaculum from the edge of the quadriceps tendon to the LPFL attachment site at the lateral epicondyle. The end of the graft is secured with the use of a No. 2 loop suture. The graft is then turned 90° laterally, twisted 180°, and passed through the subfascial tunnel with the use of a passing suture. The graft is fixed to the LPFL attachment at the lateral epicondyle with the use of a knotless anchor.