The first feline hip replacement in the New York area was performed in March 2007. Although the surgery is common for humans, veterinary medicine has just begun to practice this on cats. It is usually performed, as in humans, to replace a painful or damaged hip joint, where no better alternative exists. Because animals under about 40 lb (20 kg) carry their own weight with little strain on each leg, hip modification surgeries are often sufficient to restore hip function in many cases