Medial patellofemoral ligament

The medial patellofemoral ligament (MPFL) originates from the medial femoral condyle (between the adductor tubercle, medial femoral epicondyle and gastrocnemius tubercle) and inserts onto the superomedial aspect of the patella. The MPFL is approximately 55-60 mm in length and has a fan-like or hourglass shape, fanning out at both ends. It is a part of the medial retinaculum and is closely associated with the vastus medialis obliquus muscle, which contributes to its dynamic stability. The MPFL's primary function is to resist lateral patellar subluxation, particularly in the early degrees of knee flexion.

Note: The medial retinaculum and the medial patellofemoral ligament are distinct anatomical structures but the medial patellofemoral ligament may be considered as a part of the medial retinaculum, forming the patellofemoral complex together with the medial quadriceps tendon femoral ligament. :

• The medial retinaculum is a part of the superficial layer of the medial compartment of the knee. It is composed of fibrous tissue that extends from the medial aspect of the patella to the surrounding soft tissues, including the vastus medialis obliquus muscle.

• In contrast, the medial patellofemoral ligament is a distinct ligament located in the intermediate layer of the medial compartment. It originates from the medial femoral condyle and inserts onto the medial aspect of the patella. The MPFL is the primary passive restraint against lateral patellar displacement, contributing significantly to patellar stability, especially in the early degrees of knee flexion. The MPFL is a well-defined structure that can be isolated and described anatomically, with specific origins and insertions.