Since this cartilage gets its nourishment from the fluid within the joint and not from the blood supply of the underlying bone, it remains alive for quite some time after the initial degeneration begins. In the later stages, cartilage damage ultimately leads to advanced degenerative arthritis involving the entire hip joint. At first the patient with AVN has no symptoms. Later the buildup of pressure within the femoral head may cause a mild and vague type of pain. Once collapse of the joint surface occurs, the pain usually increases dramatically and may become severe.
Some patients however have only mild discomfort in spite of significant involvement of the joint.
As the process continues, most patients develop a limp and note some decrease in motion of the hip joint. Early on, routine x-rays in AVN are entirely normal. Later actual flattening of the normally round femoral head may be seen. Thinning of the cartilage of the joint results in narrowing of the joint space. This will show on an x-ray.