 Participants will complete a brief medical history and physical exam. They will fill out a 30-minute questionnaire that includes questions on demographics such as age, ethnicity, marital status, etc., medication history, work history, hip surgeries, and assessment of functional disability. Fifty milliliters about 3-13 tablespoons of blood will be drawn for gene testing, and X-rays will be taken of the pelvis, lower back, and neck, if recent X-rays within 1 year are not available. Women of childbearing age will have a urine pregnancy test before having X-rays. 