There are many conditions that can result in degeneration of the hip joint. Osteoarthritis is perhaps the most common reason that patients need to undergo hip replacement surgery. This condition is commonly referred to as "wear and tear arthritis." Osteoarthritis can occur with no previous history of injury to the hip joint. The hip simply "wears out." There may be a genetic tendency in some people that increases their chances of developing osteoarthritis.

Avascular necrosis is another cause of hip joint degeneration. In this condition, the femoral head (the ball portion) loses a portion of its blood supply and actually dies. This leads to collapse of the femoral head and degeneration of the joint. Avascular necrosis (AVN) has been linked to alcoholism, fractures and dislocations of the hip, and long-term cortisone treatment for other diseases. Abnormalities of hip joint function resulting from fractures of the hip and some types of hip conditions that appear in childhood can lead to degeneration many years after the injury. The mechanical abnormality leads to excessive wear and tear, much like the out-of-balance tire that wears out too soon on your car