Osteoarthritis

Osteoarthritis (OA) is a joint disease, not a bone-density disease. It happens when the slippery cartilage that cushions the ends of your bones wears down over time, causing the joint surfaces to rub together. This leads to pain, stiffness, swelling, and sometimes bone spurs, most often in the knees, hips, hands, and spine. It's sometimes called 'wear and tear arthritis' because it tends to build up gradually with age and joint use.

People often confuse osteoarthritis with osteoporosis, but they are very different conditions. Osteoporosis is a loss of bone density and strength that makes fractures more likely, usually with no pain until a bone actually breaks. Osteoarthritis is joint damage that causes pain, stiffness, and reduced movement, while your bone density itself may be completely normal. You can have one, both, or neither.

Osteoarthritis matters for bone health conversations because it can affect how your bones are measured and treated. Advanced OA in the spine, along with bone spurs or vertebral changes, can artificially raise DXA scan readings at the lumbar spine, making bone density look better than it really is. It can also make certain joint-loading exercises uncomfortable or impractical, which is something to discuss with your doctor or physical therapist when planning safe activity.