The patella rests within a groove along with the femur known as the trochlear groove. After you bend and straighten your knee, the patella moves back and forth inside this groove. The operation ordinarily normally takes between one and three hrs. The surgeon makes a Slice down the front of the knee, http://knee cap replacement https://www.theorthopaedicandpainpractice.com/knee-cap-replacement-understanding-the-basics-of-this-orthopaedic-surgery/