The patellofemoral joint is the contact area between the undersurface of the patella and the groove of the femur bone.
The patellofemoral joint (circled) is not a fixed articulation like most of the other joints in the body, but rather instead it is the area where the patella glides in the underlying femoral groove.
The three compartments of the knee joint - one patellofemoral compartment and two tibiofemoral compartments.
The other two compartments are the two tibiofemoral compartments between tibia and femur.
A blow may split the soft articular cartilage, while either force may result in a bony fracture of the patella.
"....Assessment of patellofemoral symptoms must include ruling out "major ligament instability" while the "“patellar grind” test has been described as a confirmatory test for patellar chondromalacia. Often imaging studies are indicated ...and... may include: AP, Lateral, Long Leg Standing, Insall-Salvanti, Merchant, and or Sunrise views. In selected cases the MRI may be indicated...."