Femoral trochlea

The femoral trochlea is a groove located on the anterior aspect of the distal femur, which plays a crucial role in the patellofemoral joint by guiding the patella during knee flexion and extension.

The trochlear groove is characterized by its lateral and medial facets, with the lateral facet typically being more prominent and higher than the medial facet. This asymmetry helps stabilize the patella and prevent lateral dislocation.

The trochlear groove is positioned laterally relative to the mechanical axis of the femur and consists of a laterally oriented proximal part and a medially oriented distal part.[1] The shape and orientation of the trochlear groove can vary significantly among individuals, and it has been classified into different types based on the turning points located on various cross-sections.[1] The sulcus angle, which is the angle between the medial and lateral facets, is an important parameter in assessing the morphology of the trochlea. A normal sulcus angle is typically around 146 degrees, but it can vary with knee flexion.[2]

The depth and shape of the trochlear groove are also influenced by factors such as femoral anteversion and the overall geometry of the distal femur. Increased femoral anteversion is associated with a flatter, more dysplastic trochlea, which can predispose individuals to patellofemoral instability.[3] Additionally, the trochlear groove's depth and orientation are crucial for effective patellar tracking and can compensate for certain anatomical variations in the tibia.[4]