Medial articular facet of patella

The medial articular facet of the patella is one of the two main articular surfaces on the posterior aspect of the patella, the other being the lateral facet. The medial facet is generally smaller and less steep than the lateral facet. It is concave in shape and articulates with the medial trochlear surface of the femur. The medial facet is separated from the lateral facet by a vertical ridge, and in most individuals, there is also an "odd facet" located at the extreme medial edge, which only comes into contact with the femur during deep knee flexion.