Osteoarthritis is a progressive disease so that it will get worse over time. For most people, it develops in the spine, hips, and knees because they are weight-bearing joints. It also is commonly found in the fingers but can develop in any joint in the body. Osteoarthritis is wear-and-tear of the cartilage that cushions bones in the joints. As the cartilage deterioration progresses, the bones in the joint begin to rub together, leading to pain and reduced joint mobility. The frayed cartilage and bone rubbing may lead to inflammation of surrounding tissues and joint swelling. If left untreated, a severe loss of cartilage and slipping bones can lead to deformities, like bow-leggedness and bent fingers, bone growths on fingers, and bony spurs on the spine.