Crepitus

Extended Definition

Crepitus is the medical term for the crunching, grinding, cracking, or popping sensations and sounds that can occur in joints. While occasional joint popping is normal and usually harmless (often caused by gas bubbles in synovial fluid), persistent or painful crepitus is often a sign of joint problems, particularly osteoarthritis.

In arthritic joints, crepitus typically occurs when damaged cartilage surfaces and exposed bone rub against each other during movement. The sensation might feel like coarse sandpaper grinding, or you might hear audible creaking or cracking sounds. The roughened surfaces of worn cartilage and the irregular bone surfaces created by bone spurs contribute to these sensations.

You might notice crepitus when walking up stairs, squatting, or bending your knee. In the knee, it’s sometimes felt as a grinding sensation under the kneecap (patella) when extending or bending the leg. While crepitus itself isn’t necessarily painful, it’s often accompanied by pain, stiffness, and swelling in joints with osteoarthritis. The presence of crepitus, especially when combined with other symptoms like pain and limited mobility, is often an indicator to seek medical evaluation. While crepitus cannot be “cured,” treatments that address the underlying arthritis—such as exercise, weight management, and in some cases injections or surgery—may help reduce symptoms.