A progressive, degenerative joint disease, the most common form of arthritis, especially in older persons. The disease is thought to result not from the aging process but from biochemical changes and biomechanical stresses affecting articular cartilage. In the foreign literature it is often called osteoarthrosis deformans.
A benign osteoblastic tumor with central vascularized nidus surrounded by normal reactive bone. It occurs especially in second decade of life most commonly in the femoral neck but can occur in any bone and any site within a bone.