The Knee Injury and Osteoarthritis Outcome Score (KOOS) Jr. and Hip Injury and Osteoarthritis Outcome Score (HOOS) Jr. are survey instruments designed to assess patients’ opinions about their knee, hip, and associated problems. It is formatted as a brief, self-administered survey. The KOOS survey includes questions on: stiffness, pain, function in daily living, and knee-related quality of life. The HOOS survey includes questions on: pain, function in daily living and hip-related quality of life. Numerical values are assigned to a series of response options, such as none (0), mild (1), moderate (2), severe (3) and extreme (4), and mean scores are calculated using this data. The higher the numerical values, the higher the overall functional difficulty associated with the knee or hip. The lower the numerical values, the lower the overall functional difficulty associated with the knee or hip.