From my observations, the lower dissection pics of the knee area, it looks like the joint that keeps the tendon in its channel failed and it started a repair with the tendon on the outside, thus all the calcium growth. That bird was only going to get worse. Good decision. Gerald BarkerMaybe someone can spot something in these pics I haven't noticed. The swelling is very hard and when the bird was alive very warm. The bird could not stand on the leg and was in a lot of pain. The first incision is around and through the swollen area. The yellow in the center is very hard and crunchy, I believe it is calcium. The white under the skin is very much like gristle. I cut through the bone in the middle of the swollen area. This is the second cut through the bone. It appears to me that the bird had a green fracture that was mending or growing out of control.