This is the wearing away of the protective cartilage over time. While osteoarthritis can be painful, many people who have osteoarthritis do not experience any pain at all. Osteoarthritis in the hip can be difficult to diagnose early, because pain may be felt in the groin, buttock, thigh or even the knee. The pain can vary from a dull ache to a sharp pain. This is why a good diagnosis from a joint expert is so important.