8 Facts about Knee Popping and Clicking

What type of knee clicking are we talking about?

Here are the most commonly described sensations by people who are curious about knee clicking.

Most frequently reported sensations when the knee click and pop?

Where did I get this information? I simply looked at the most commonly used keywords on the internet related to knee clicking and popping: you will likely find yourself in one of these situations!

Sensation	Explanation
Clicking knee with pain, knee pain when it clicks, loud pop in knee followed by pain, knee clicking and aching	Very common, often a sign of “normal” clicking. To identify if it’s a “normal” clicking (I’ll come back to this; it’s usually the case, even if your knee hurts), you need to distinguish if 1/ the pain is really related to the clicking (did you not have pain before?) and 2/ if it’s just at the moment or if it lasts for several days without calming down after the clicking episode.
Clicking knee with side pain	The precise location of pain during clicking doesn’t really help identify the cause of the (possible) problem.
Knee clicking while biking	Very common, often a sign of “normal” clicking.
Clicking knee without pain	Very common, often a sign of “normal” clicking.
Knee clicking after ligamentoplasty	Very common, often a sign of “normal” clicking: it’s rare for it to be due to a rupture of the repaired ligament (if that’s the case, you generally have severe pain and feel your knee is very different and unstable since the clicking).
Clicking knee when straightened with pain	Very common, often a sign of “normal” clicking.
Clicking knee when bending, knee popping when extending	Very common, often a sign of “normal” clicking.
Clicking knee while walking	Very common, often a sign of “normal” clicking.
Clicking knee and swollen	Very common, often a sign of “normal” clicking. Was the knee already swollen before the clicking (continuously or occasionally), or do you feel it really just swelled after (in the hours following the clicking)?
Knee clicking meniscus	It is often thought that knee clicking is a meniscus problem. While many people have a “problem” with the meniscus (meniscus tear), yes, some have knee clicking, but it’s generally not related to the meniscus! Knee clicking is not at all a sufficient sign to suggest a meniscus tear or another meniscus problem.
Knee creaking on touch	Very common, often a sign of “normal” clicking.
Clicking knee all the time	Very common, often a sign of “normal” clicking.
Clicking knee locking and clicking	Very common, often a sign of “normal” clicking.
Clicking patella	Very common, often a sign of “normal” clicking. You can feel this clicking almost anywhere.
Knee clicking arthritis	It is also often thought that knee clicking is an arthritis problem. While many people have an “arthritis problem,” yes, some have knee clicking, but it’s not necessarily related to arthritis! Knee clicking is not at all a sufficient sign to suggest knee arthritis.
Knee cartilage clicking	The cartilage is often blamed, after arthritis or the meniscus, as the cause of clicking (for example, knee chondropathy). However, as you will see later, it is usually not a knee cartilage problem! In any case, knee clicking is not at all a sufficient sign to suggest a cartilage problem.
Clicking after knee replacement	Even if it’s surprising when it happens, clicking often occurs relatively frequently in the weeks following the operation (even if you didn’t have it before) (in 1 out of 5 people). And sometimes, it lasts “for life,” usually without associated pain. It’s entirely benign. Various factors related to the patient, the prosthesis, and the surgical technique can explain it. (Sang 2018)

To summarize, here are the statements from a German research team 🇩🇪 that synthesized knowledge about knee pain associated with cracking:

Many people who suffer from knee pain may feel or hear cracking, popping, or grinding sounds when they move the affected knee.

However, this is not a cause for concern: There is no connection between the sounds of the knee and knee pain or function.

Many people have “noisy” knees without experiencing pain or other knee problems.

InformedHealth.org 2023

Are creaking knees common?

A second reassuring element: knee clicking is VERY common.

• 38.1% of women and 17.1% of men over 40 who have osteoarthritis visible on an X-ray experience these sensations;
• 96.5% of people who have had a meniscus issue;
• 18% of people who have had a total knee replacement.

We do not have figures for the general population, but my experience leads me to believe that a large percentage of adults are affected.

Source: Sang 2018

What happens in the knee when it cracks or grinds?

📢 In the vast majority of cases, the cracking in your knee is physiological. This means it is “normal” and not due to a problem. This is also true for all joints.

In medical terminology, this is called “crepitus.”

The exact process of how it happens is not fully understood. But here’s the most likely hypothesis:

1. You bend or extend your knee (even just a little).
2. This changes the pressure in your knee joint and the synovial fluid (a fluid present in all our joints, making them flexible).
3. This change in pressure may promote the formation of small gas bubbles, mainly carbon dioxide, in the synovial fluid.
4. These formed gas bubbles can suddenly burst when they encounter sufficient pressure.
5. The bursting of these bubbles creates the cracking sound that you hear or feel.

I will list later the (very rare) situations where knee cracking is not normal and requires consultation.

But if you are reading this article, the probability is VERY high that you fall into the “normal knee cracking” category!

Other possible explanations for normal knee cracking include:

• Ligament snapping
• Movement of a meniscus
• Tissue in the joint (synovial membrane) getting caught and then releasing
• Noticing a sound that existed before a stressful event (such as surgery) but was not perceived.

Source: Sang 2018

What Causes Knee Cracking?

Reasons and Significance In the vast majority of cases, the significance of knee cracking is simply a well-known and normal reaction of our joints: the phenomenon of crepitus that I just described.

Much more rarely, another cause may be behind these knee crackings. As a physiotherapist or doctor, we are trained to identify them, to perform what is called a differential diagnosis: ruling out causes that would require specific treatment or attention.

Here are these rare causes of abnormal knee popping. I will explain later how to recognize them.

• Meniscus injury: an audible cracking, occurring suddenly (once), especially accompanied by pain or swelling, may be related to meniscus injuries;
• Rupture of a knee ligament: such as the anterior cruciate ligament, instability of the patella.
• Rupture of a knee tendon (patellar tendon, quadriceps): this will generally be accompanied by intense pain and an inability to use the knee.
• Pathological plica: an abnormal fold of the synovial membrane inside the knee joint. Source: Sang 2018

What are the consequences if your knee clicks often?

There is absolutely no need to worry if your knee clicks frequently (in the by far most common case where it is indeed a physiological clicking).

This is NOT a sign of any problem.

This does NOT mean that you are sure to have arthritis, a meniscus problem, or cartilage issues, now or in the future.

Source: Lo 2018

Here are also reassuring statements from an Australian-Brazilian research team 🇧🇷:

Knee clicks are not associated with a higher risk of having a knee prosthesis.

Clicks do not affect the physical function and quality of life of patients with knee arthritis.

Ferraz 2019

In simpler terms, even if your knees click often:

❌ you are no more likely to have a knee prosthesis one day (no more than a person whose knees don’t click)
❌ if you also have arthritis, you are no more likely to have difficulties doing things.

Can anything be done to avoid knee clicks?

No, there is absolutely nothing to do to eliminate or reduce the frequency of knee clicks.

Of course, you will always find people (therapists or not) recommending various remedies or grandmother’s recipes to avoid knee clicks.

But these clicking phenomena are natural, very common. It is challenging to imagine a reasonable explanation for any treatment or remedy to eliminate or alleviate this phenomenon.

Should you treat a clicking knee?

No, as explained earlier, there is no remedy, treatment, or solution to avoid knee clicks.

So, if you have a physiological, normal clicking, not due to a more serious problem, there is no need to treat this knee.

Of course, if you have significant pain or discomfort in your activities, things can be put in place.

But the goal will not be to treat the knee click but the other symptoms (pain, lack of flexion, morning stiffness, etc.).

In the rare cases where the click is not normal, there are generally things to do under medical or paramedical supervision to guide you.

Exactly, I will now detail when to worry about knee clicking: when can it indicate something abnormal?

When to worry about knee clicking?

If reading this article has reassured you and makes you think that you have simple crepitus (= normal knee clicks), then a medical consultation does not seem necessary.

If you still want to discuss it with a healthcare professional in a personalized way, you can certainly talk about it during your next scheduled appointments for something else.

In which case does a specific and rapid consultation seem necessary?

Here’s what a Korean research team 🇰🇷 says about this:

The best way to differentiate between a physiological noise and a pathological noise is to check for the presence of pain and swelling/effusion in the knee joint.

Furthermore, physiological noise is not associated with a history of injury, does not worsen with combined sounds and symptoms, and has a sporadic nature due to the accumulation of air in the joint fluid.

Sang 2018

In more understandable terms, what does it mean?

🟢 Situation where you don’t need to worry about knee clicking

• You have not recently injured or twisted your knee.
• You don’t have more pain in your knee when it clicks.
• The clicking occurs from time to time (or often) but irregularly.
• You do not have significant knee pain that prevents you from walking, bending, or straightening it.

🚨 Situation where you may seek the advice of a healthcare professional for knee clicking

• You have recently injured your knee.
• When you hear or feel the click, you have very significant pain at the same time.
• You can hardly walk, bend, or straighten your knee.
• Your knee is visibly deformed since the click.
• Your knee has swollen a lot after the click (and not due to another event like surgery).

Who to consult for a clicking knee?

If you can no longer move your knee at all, put weight on it, and the pain is intense, an emergency room consultation seems necessary. But if you are reading this article, it’s probably because you are not in this situation!

In other cases, your general practitioner will probably be able to answer your questions and reassure you.

Physical therapists, sports doctors, orthopedic surgeons, and rheumatologists are also professionals accustomed to dealing with knee clicks.

However, it is less common to consult them as a first resort (that means without being directed by your general practitioner).

Depending on your feelings and the examination performed by healthcare professionals, additional tests (such as an X-ray or an MRI) are sometimes carried out. The goal is to rule out a problem that would require specific treatment, such as a knee fracture.

If you haven’t had any additional tests, it means your doctor believes there is no cause for concern. X-rays or MRIs are not something trivial, which is why they are ideally not prescribed “just in case”!

***

Here’s what I wanted to tell you about this! Do you have any comments or questions? Your comments are welcome 🙂 !

You may also like:

• Main Causes of Painfull and Swollen Knee
• Cycling with Arthritic Knee
• Walking with Arthritic Knee

 📚 SOURCES

InformedHealth.org [Internet]. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2006-. Patellofemoral pain syndrome (runner’s knee): Overview. 2020 Aug 13. Available from: https://www.ncbi.nlm.nih.gov/books/NBK561507/

Lo GH, Strayhorn MT, Driban JB, Price LL, Eaton CB, Mcalindon TE. Subjective Crepitus as a Risk Factor for Incident Symptomatic Knee Osteoarthritis: Data From the Osteoarthritis Initiative. Arthritis Care Res (Hoboken). 2018 Jan;70(1):53-60. doi: 10.1002/acr.23246. Epub 2017 Dec 8. PMID: 28470832; PMCID: PMC5671376.

Pazzinatto MF, de Oliveira Silva D, Azevedo FM, Pappas E. Knee crepitus is not associated with the occurrence of total knee replacement in knee osteoarthritis – a longitudinal study with data from the Osteoarthritis Initiative. Braz J Phys Ther. 2019 Jul-Aug;23(4):329-336. doi: 10.1016/j.bjpt.2018.09.009. Epub 2018 Sep 30. PMID: 30292656; PMCID: PMC6630108.

Saubade M, Karatzios C, Léonard E, Besson C, Gremion G, Gremeaux V. « Mes articulations craquent, c’est grave docteur ? » Les bruits articulaires en question [« My joints are cracking, is it serious doctor ? » A review about sounds produced by joints]. Rev Med Suisse. 2017 Jul 12;13(569):1334-1338. French. PMID: 28699710.

Song SJ, Park CH, Liang H, Kim SJ. Noise around the Knee. Clin Orthop Surg. 2018 Mar;10(1):1-8. doi: 10.4055/cios.2018.10.1.1. Epub 2018 Feb 27. PMID: 29564040; PMCID: PMC5851845.