Crepitus, sometimes called crepitation (krep-i-tay-shen), describes any grinding, creaking, cracking, grating, crunching, or popping that occurs when moving a joint. People can experience crepitus at any age, but it becomes more common as people get older.
Common causes of creptius include:
- Air bubbles popping inside the joint. This popping does not cause pain.
- Tendons or ligaments snapping over the joint’s bony structures. This snapping sometimes causes pain.
- Arthritis—typically either osteoarthritis or rheumatoid arthritis—that causes a joint’s articular cartilage to degenerate.
- While arthritis often leads to pain, not everyone with joint degeneration will experience it.
It happens to nearly all of us: You get out of bed in the morning or stand after sitting for a while and your knee pops.
When joints create a grinding or popping sound or sensation, this is known as crepitus. Occasional joint crepitus is considered normal and is no cause for alarm.
However, a large new study suggests that frequent knee crepitus may be an early warning sign of knee osteoarthritis.
The study included nearly 3,500 middle-age individuals with no initial symptoms of knee osteoarthritis and tracked them for 2 years. Researchers found that participants who reported having no knee pain, but frequent or constant knee crepitus, were at higher risk for having symptoms of osteoarthritis within a year.
This was especially true for those with physical signs of knee degeneration (via X-ray results) at the beginning of the study—despite making up only 26% of the total study group, 75% of them went on to develop symptoms of osteoarthritis.
More research is needed to establish what the connection is between frequent crepitus and osteoarthritis. But crepitus’s possible role as a warning sign of osteoarthritis means that people who experience frequent crepitus can take measures to protect their joints.
Osteoarthritis can’t be cured or prevented, but the sooner treatment starts, the easier it is to manage symptoms and slow degeneration.