Duke University Medical Center researchers have discovered key differences in arthritic knee and hip joints using analytical tools they developed, which could lead to new ways of treating osteoarthritis. Knee joints are constantly repairing themselves, while hip joints are not. This means that a more targeted approach to stop degradation of the knee could be effective, while a focus on both stopping degeneration and stimulating repair would be the best treatment for hip joints in patients with osteoarthritis."This suggests the knee has capacity for repair we didn't know about and the main treatment strategy probably would need to focus on turning off the breakdown of knee tissue," explains Virginia Kraus, professor of Rheumatology and Immunology at Duke. The findings were surprising because hips are ball-in-socket joints like ankles, which are less susceptible to osteoarthritis, while knees require tissue such as the meniscus to fit properly.