Patellofemoral arthritis occurs when the articular cartilage alongside the trochlear groove and within the underside from the patella wears down and becomes inflamed. Those with osteoarthritis only in a single 50 % on the knee joint (the inner side) really should be supplied the choice of partial or total replacement. http://knee cap replacement https://www.theorthopaedicandpainpractice.com/knee-cap-replacement-understanding-the-basics-of-this-orthopaedic-surgery/