Cracking, popping and clicking in the knee is a very common occurrence, with studies supporting that the vast majority of people will have some knee crepitus (noisy knees) at some point within their lifetime.
The two main determining factors to distinguish whether the crepitus is nothing to worry about or if you should get it assessed is;
- Is it painful clicking?
- Does it limit the ability to bend or extend your knee?
If the answer is no to both, then the crepitus is nothing to worry about and is considered a normal ‘physiological’ crepitus that occurs with normal knee function. This crepitus in the knee may be caused by:
- Synovial fluid – The fluid that lubricates all the joints of the body. As a by-product of this fluid, gas bubbles can build up within the joint and then ‘pop’ as the joint moves, causing an audible sound.
- Patellofemoral joint – the kneecap slides up and down in a small groove to help facilitate movement in the knee. This movement can create small clicking sounds due to the uneven surfaces of the kneecap within the groove
- Tendons/ligaments – tendons and ligaments are tight bands of tissue, and they can flick over each other or over bony prominences in the knee, giving a clicking sensation typically when bending the knee
If the answer to one or both of those questions is yes, this can be a sign of injury or dysfunction. Causes of this may include:
- Patellofemoral pain syndrome – painful clicking or popping of the kneecap is a sign that the kneecap is tracking poorly in its groove or it is overloaded.
- Cartilage wear/osteoarthritis – crepitus in the knee associated with arthritis will be accompanied by stiffness in the joint, as well as swelling and pain with movement.
- Meniscus – the meniscus is a layer of cartilage within the knee joint that acts as cushioning. A tear in the meniscus can cause a painful click that may also be associated with catching and locking of the knee joint.
Important to note:
- Crepitus is not a sign of “bone-on-bone” knees
- There is no evidence to suggest that crepitus “wears the knee out” or causes arthritis
- Crepitus is not a predictor of pain and/or future knee function
- There is no evidence to suggest that crepitus gets worse as we age
Unsure about your knees? Contact our friendly team to get help now!
Source: ABC
Title: Why do my knees click?
Read time: 5 mins