Crepitus describes any audible sounds (cracking, creaking, clicking, grinding, grating, etc.) coming from a moving joint. Hearing this for the first time, can be a very alarming process for a patient, especially when it comes on innocuously.
However, crepitus is normal and currently there is no research that shows a definitive link between noise and pathology. In fact, 99% of individuals with knee (patella-femoral) crepitus had no associated pain!
Image source: https://health.clevelandclinic.org
A few reasons to explain these sounds include:
- Tendons or ligaments moving over bony landmarks;
- Inside the joint, we have fluid surrounding our joints known as synovial fluid. Joint surfaces can cause a vacuum which causes gas within the synovial fluid to collapse (this is the popping sound we may hear); and
- Hypomobility/stiffness of joint surfaces (lower limb joint is lubricated through weight-bearing activities, a reduction of this may cause increase crepitus)1.
Interestingly enough, habitual cracking of your knuckles has shown no signs or correlations with increased osteoarthritis2!
To recap, there are a number of structures and mechanisms that may cause crepitus from a joint3. Most of these are pain-free and completely harmless. However, if your crepitus is painful or is causing reduced functioning, please contact the team at Back In Motion Eltham for an assessment and rehabilitation plan.
If you have any questions about joint crepitus, please contact Cameron at Back In Motion Eltham on 9439 6776 or c.ramlu@backinmotion.com.au
References:
- Protopapas, M. G., & Cymet, T. C. (2002). Joint cracking and popping: understanding noises that accompany articular release. The Journal of the American Osteopathic Association, 102(5), 283-287.
- Castellanos, J., & Axelrod, D. (1990). Effect of habitual knuckle cracking on hand function. Annals of the rheumatic diseases, 49(5), 308-309.
- McCoy, G. F., McCrea, J. D., Beverland, D. E., Kernohan, W. G., & Mollan, R. A. (1987). Vibration arthrography as a diagnostic aid in diseases of the knee. A preliminary report. The Journal of bone and joint surgery. British volume, 69(2), 288-293.