Knee popping is a common knee problem. It is not actually limited to knee popping sounds alone; the term also covers other sounds produced by the knees like snapping or grinding. Medically, the knee popping condition is called Crepitus, a term that essentially means a “noisy joint”.
This common occurrence can be caused by a number of factors. These factors can be categorized by each type of knee popping or snapping conditions. The categories are:
- Pain-free knee popping
- An injury induced painful popping noise
- Recurrent popping which is not caused by any injuries or trauma
Pain-free Knee Popping
There are times when you are plagued with a popping sound produced by your knee joints. If without any associations to pain, the condition is nothing to worry about although it can be very disconcerting. It can be caused by factors such as:
- Gas bubbles
– Bubbles of gas are produced when there are changes in the joint pressure. These bubbles tend to burst as quickly as it has been produced, and when they do, a popping sound can be heard. Medically, it is called cavitation. Presently, there are no known harmful effects of cavitation other than the disturbing knee popping sounds. There is a myth however that the condition can lead to arthritis, but as it has been said, it is only a myth and is still unfounded.
- Sounds caused by the movement of ligaments and/or tendons
– When our joints moved, the ligaments and/or tendons may slightly stretch over a joint’s bony lump. After the stretch it will then snap back into position but not without a popping sound. It doesn’t produce any pain and it can’t make you at risk for any joint injuries.
An Injury-Induced Painful Popping Noise
In contrast to the pain-free knee popping noises, an injury can also produce the same sounds but with pain attributions. When you get injured and there is a “pop”, it is most likely that a ligament has been damaged. There are 2 most common ligament injuries that produce this sound, they are:
- ACL Injury
– The anterior cruciate ligament or ACL is the ligament that connects the thigh bone to the leg bone. It can be injured or damaged when a blow is applied to the side of the knee, there is a sudden twist or deceleration or when there is an overexertion of backward bending of the knees.
- MCL Injury
– MCL or the medial collateral ligament is one of the four knee ligaments inside the joint. It can be injured by a sudden twist or by an external force applied to the knee. A knee popping sound can both be heard in most injury cases involving the ACL and/or the MCL tearing.
Other injury-induced causes are:
- Sprains and strains in tendons and kneecaps
- Fractures in the different parts of the knee joint like the caps and other major bones
- Kneecap dislocation
Recurrent Painful Knee Popping
The causes of this chronic sound and pain are the following:
– The tearing of the knee’s rubbery cushion
– Caused by the gradual wear and tear of the cartilage
– The irritated and inflamed cartilage located at the back of the knee cap
– A throbbing ache around the knee caused by constant rubbing of the patella and femur. Common among runners