After pulling the skin upward, a small incision is made over the upper expanded border of each condyle, and the points of an ice-tong calliper are made to grip the bone without penetrating into the cancellous tissue.
"Manual of Surgery Volume Second: Extremities--Head--Neck. Sixth Edition."
Alexander Miles Alexis Thomson
It would seem that the first change is one of congestion of the vessels of the bone's cancellous tissue.
"Diseases of the Horse's Foot"
Harry Caulton Reeks
Hence this is called cancellous tissue, and the gradual transition from one to the other is apparent.
"A Practical Physiology"
Albert F. Blaisdell