It makes a popping sound when you bend your knees.
In addition to the sound, I think there are various symptoms such as pain, swelling, and difficulty in stretching the knee.
In such a case, there are cases where it is better to see the situation as it is, and cases where it is better to consult a medical institution. Here, we will explain the causes of popping when you bend your knees, the diseases you should be aware of, and how to deal with them.
table of contents
Causes of popping knees
Knee popping can be caused by both non-disease and disease. It should be noted that it is due to illness.
not caused by illness
①Due to aging and lack of exercise１
The knee is a joint that connects the bones of the thigh, knee, and calf, and cartilage and joint fluid act as a cushion to prevent these bones from rubbing against each other, allowing smooth movement.
When the knee joint becomes distorted due to aging or lack of exercise, air enters the joint fluid, and when the knee is bent, the air bursts and makes a popping sound.
After that, the air does not accumulate immediately, so there is no sound for a while, but after a while, it will pop again.
If you don't have any symptoms other than the sound, it's often good to see how it goes.
(2) Caused by sudden exercise
Contrary to the lack of exercise mentioned above, even when pressure is applied to the knee due to sudden exercise, air enters the joint fluid and bursts.
The result is a popping sound. In this case as well, if there are no symptoms other than the sound, you should wait and see.
reference)
１ Why do my knees pop when I bend them? Introducing 3 causes and how to cure (teru-saishin.com)
caused by illness
① Knee osteoarthritis２
Osteoarthritis of the knee refers to the deformation of the knee due to the loss of cartilage and joint fluid in the knee due to aging, obesity, and genetics. It may also appear as a sequela of a fracture or meniscal injury.
Symptoms include popping sounds when the knee is bent, pain and swelling, difficulty walking, bow legs, and inability to straighten the knee.
Examinations show an increase in joint fluid (so-called “watering”) due to inflammation.
It is more common in women with a male to female ratio of 1:4.
(2) Chondromalacia patellar３
Chondromalacia patellar is a decrease in thigh muscle strength and knee joint flexibility, which causes the cartilage on the back of the knee bone (so-called “knee cap”) to deform or collapse during exercise. refers to
Symptoms include severe pain around the knee and behind the knee when standing, walking, running, climbing stairs, etc. In terms of gender and age, there is a tendency for young female runners and those who wear high heels to be more likely.
reference)
２ "Osteoarthritis of the knee"｜Japanese Orthopedic Association -Symptoms and diseases (joa.or.jp)
What to do when your knee pops
There are things you can do yourself and things you can do at a medical institution as a coping method when your knee pops.
If it is not caused by any of the diseases mentioned above, you may try to deal with it yourself first. If it is caused by an illness, do not treat it on your own, and consult a medical institution.
do-it-yourself４
If you have no symptoms other than popping knees, muscle training, proper weight management, and warming your knees are effective. In order to reduce the burden on the knees, it is important not to concentrate the weight-bearing part only on the knees.
Therefore, train the front thigh muscles (quadriceps) and try to lose weight if you are obese. Also, if you warm your knees, fatigue substances that have accumulated due to poor blood circulation may be eliminated, making it difficult to make sounds.
What to do at a medical institution４
① Dealing with drugs
It is the treatment of choice for both knee osteoarthritis and chondromalacia patellar.
If you have symptoms other than popping knees, but the pain is mild, or if there is little swelling or deformation, you may be treated with anti-inflammatory drugs or analgesics. There are oral medicines, poultices, and suppositories.
② Hyaluronic acid injection
It is the treatment of choice for osteoarthritis of the knee.
There is an injection of hyaluronic acid. Since hyaluronic acid is one of the sources of synovial fluid, it is injected when synovial fluid is reduced to artificially create a cushion so that the bones do not rub against each other.
For both ① and ②, it is important to note that taking medicine will not cure the disease itself, so under the doctor's instructions, you will also take measures on your own, such as muscle training and appropriate weight management.
(3) Secure bed rest
This is the treatment of choice, especially in the case of chondromalacia patellar.
Many people with chondromalacia patellar are caused by sports, so we will stop sports for the time being and perform rehabilitation such as muscle training while securing knee rest.
④ Treatment by surgery
It is the treatment of choice for osteoarthritis of the knee.
Surgery is recommended if there is pain, swelling, or deformation that cannot be relieved with medication, or if it is already difficult to walk and has a significant impact on daily life.
Typical surgeries include arthroscopic (endoscopic) surgery, high tibial osteotomy, and total knee arthroplasty.
In mild to moderate cases, arthroscopic surgery and high tibial osteotomy are often performed, and in severe cases, artificial knee joint replacement is said to be suitable.
reference)
summary
This time, I talked about the causes of popping when you bend your knees, the diseases to be careful of, and how to deal with them.
If there is only a popping sound, it is often good to see how it goes, but it is necessary to be careful if pain, swelling, or difficulty in stretching the knee gradually develops.
If you are already experiencing symptoms other than the ringing sound, please consult a doctor as soon as possible, as the severity of the disease will change, so be sure to visit a medical institution.
Supervision: Dr. Yasushi Tsuda