Which of the following structures helps stabilize the patellofemoral joint?

The stabilization of the patellofemoral joint is significantly influenced by the medial and lateral retinaculum. These structures are important because they consist of fibrous tissue that attaches to and supports the patella, helping to keep it aligned within the knee joint during movement. The medial retinaculum provides support on the inner side of the patella, while the lateral retinaculum provides support on the outer side. This balance is crucial for maintaining proper tracking of the patella during flexion and extension of the knee, which prevents dislocations and other issues related to joint instability.

Other structures mentioned, like the anterior and posterior cruciate ligaments, primarily stabilize the knee joint itself by controlling its movements, rather than specifically stabilizing the patellofemoral joint. The popliteal ligament is involved more broadly in knee stability but does not have a specialized role in supporting the patella. The quadriceps tendon does help in the overall mechanism of knee extension and contributes indirectly to the position of the patella but does not provide targeted stabilization for the patellofemoral joint in the way that the retinacula do.