What is osteoarthritis?

Osteoarthritis is a type of arthritis that is caused by the breakdown and eventual loss of the cartilage of one or more joints. Cartilage is a protein substance that serves as a "cushion" between the bones of the joints. Osteoarthritis is also known as degenerative arthritis. Among the over 100 different types of arthritis conditions, osteoarthritis is the most common, affecting over 20 million people in the United States. Osteoarthritis occurs more frequently as we age. Before age 45, osteoarthritis occurs more frequently in males. After age 55 years, it occurs more frequently in females. In the United States, all races appear equally affected. A higher incidence of osteoarthritis exists in the Japanese population, while South African blacks, East Indians and Southern Chinese have lower rates.

Osteoarthritis commonly affects the hands, feet, spine, and large weight-bearing joints, such as the hips and knees. Most cases of osteoarthritis have no known cause and are referred to as primary osteoarthritis. When the cause of the osteoarthritis is known, the condition is referred to as secondary osteoarthritis. Source(s): Doctor

Arthritis marked by degeneration of the cartilage and bone of joints.
athritis in the back i would immagine
Osteoarthritis, or OA, is a degenerative joint disease. It primarily affects cartilage within the joints, causing it to fray, wear, ulcerate, and in extreme cases, to wear away entirely, leaving a bone-on-bone joint. At the edges of the joint, bony spurs may form. OA can cause joint pain, loss of function, reduced joint motion, and deformity. Disability results most often from disease in the spine and in the weight-bearing joints (knees and hips).
I think that means weakening of the bones.
Or hurting of the bones.
Arthritis version