Final answer:
Osteoarthritis is primarily a noninflammatory condition caused by the breakdown of joint cartilage and bone due to mechanical stress on the joints and insufficient self-repair of cartilage.
Step-by-step explanation:
Osteoarthritis is primarily a noninflammatory condition. This means that it does not typically involve significant inflammation in the joints. Instead, it is primarily caused by the breakdown of joint cartilage and bone due to mechanical stress on the joints and insufficient self-repair of cartilage. Although there may be some low-grade inflammation in the joints, it is not the main driving factor in osteoarthritis.