trochlear groove

If you are following all the parts of this keynote, you will have read the two preceding sections on the patella as a sesamoid bone and on the patella as part of the extensor mechanism. It would be worth you reading those two sections before proceeding here.

We have learned that the patella is a bone that exists within the tendon of the quadriceps muscle, and that the muscle is tethered above to the hip and bits of it to the upper femur, and that it is tethered below to the tibia bone.

The patella bone lies within the substance of the tendon of the quadriceps muscle and is in contact with the femur bone behind it.

To fully evaluate the kneecap and its relationship to the femur below it, one needs to look at the bones from above. It is easy to relate to this view, as it is the view you yourself get of the knees when sitting down.