The causes of "Cracking sound at the knee" (2010-07-14)

Uploaded by myspinalcare on 25.02.2012

Good Morning! Good morning!
This is the time of interviewing with our guest speaker.
Recently, I have learned that many of my friends are having knee trouble upon walking.
Sometimes they heard cracking at the knee when kneeling down.
And then I ask them whether you have degeneration or not.
They replied, “Maybe not!?” Since we are not doctors and we don’t know at all; what is that exactly?
So, our guest will talk about this pain syndrome; whether it is degeneration or not.
Is there a special term for it? And let him explain to you.
Welcome, Dr. Ronnie Chan. Good morning! Good morning!
When I heard people have knee pain or heard cracking at the knee, is there a special term to describe it?
In Western medical term, it is not uncommon at all. But if we translate back to Chinese, it will be quite rare.
In English first? It is called Patellofemoral Pain Syndrome.
It is called Patellofemoral Pain Syndrome. Patellofemoral Pain Syndrome!
Does it happen at the knee cap? Yes, the common term is called knee cap.
So, the medical term is not knee cap but patella? That is right.
Yes, patella and the femur, which is the thigh bone; therefore a combination of bones into a joint.
Oh, I see. This is the proper terminology. So, what is it exactly? What is the cause?
It is a pain syndrome at the cartilage of the knee cap. There are lots of different causes.
It is not necessary due to old age or degeneration. Many factors will cause this pain syndrome to occur.
Does it happen when people are reaching certain age?
If you are talking about wear and tear, it can happen as early as 30s.
So, if you can hear cracking at the knee upon kneeling and standing up …
With dizziness!? That doesn’t count.
Then, there may be an issue at the knee. And of course, it is only one of the causes.
Do flat feet affect this condition at all? Definitely.
Of course, flat feet are going to affect the knees.
Other conditions including traumas, overuses and valgus knees are possible as well.
Valgus knee means when knees are put together, the lower legs are bending outward;
which can potentially causing patellofemoral pain syndrome.
Also, like you have just mentioned, flat feet. Flat feet cause the excessive pronation of the feet and lead to knee problems.
Lastly, muscle imbalance, meaning the imbalance of thigh muscles that will cause the knee joint problems.
According to what you have explained, sitting posture, standing posture,
movements which we had done a lot and even excessive exercise can also cause this pain syndrome, right?
That is correct. In other words, we do not necessary develop this condition at an old age,
young people can also develop this, depends on how we use our knees.
For those athletes playing World Cup, could they get it? Potentially yes, that is why we need to be careful.
For the time being, we do not experience a lot of knee pain. We are just below 30 years “young”.
But how does the pain feel like? First of all, you will hear the cracking.
Really cracks. Right, upon standing from sitting.
However, if you already have this when you were small, it is not a big deal at all.
If you don’t have it, and suddenly you have, then you should be careful.
In other words, if I have the cracking already when I was small, it is ok!?
Yes, that is correct.
Oh! However, if I have the cracking suddenly, then we should be careful.
That is right.
For pain, the location should be around the knee cap; above, below, left, right and even inside are possible.
It is all around the joint? That is correct.
So, if the pain is all around the knee joint, then we should be careful? That is right.
Other causes include standing and walking too much, sitting too long, walking up/down stairs.
Sports like skiing and long distance running can possibly cause pain.
I’d like to ask; does the pain come all of a sudden or come slowly?
You will feel better after resting and pain will reoccur when you resume your activities.
So, if you don’t move, you do not feel pain at all. But when you move your knees again, the pain will come back.
It is very hard not to move them at all. That is right.
You may wonder why sitting will cause pain.
It is because sitting for a long time will cause the joint to stay in the same position too long which can cause pain.
Besides sitting, many people will cross their knees, does it also cause this pain syndrome?
Yes, it is because you are also stressing the joint which can also cause pain.
From a patient’s perspective, how do you examine the knees to find out whether I have patellofemoral pain syndrome or not?
We will need to perform an examination first, which includes a number of tests that allow the doctor to understand better.
First, we will do palpation test.
For example, move the knee cap passively to see if the”feel “of the knee is smooth, any deviation in location, or feeling grinding in between the joints.
Secondly, we can take x-ray. With x-ray, we can see if there is any injury to the cartilage, soft tissue and joint integrity.
Thirdly, we can perform orthopaedic tests, to see if the joints are functional. For instance, patient is going to laid down.
We will push the knee cap towards the foot and at the same time ask patient to extend his/her knee.
You are pushing the knee cap towards the foot…
Right and you are going to extend the knee by pressing downward.
So, you keep pushing towards the foot.
If you have find pain upon this movement, there may be patellofemoral syndrome at the knee.
Oh, I see. Lastly, we can measure the Q-angle.
The measurement of Q-angle is quite interesting.
We start to measure from the femur bone to the knee cap; this is the first line.
Then another line is drawn from the knee cap to the tibia bone.
The angle formed from the intersection of these two lines is called Q-angle.
In the middle? Coloured in purple?
That is right. Q-angle can tell us whether our knee joints are capable to sustain the stress applied daily.
For women, the Q-angle should be about 22 degrees when straighten up the knee and 9 degrees when the knee is bent.
If your Q-angle is larger than this, then you knee will potentially prone to injuries.
For men, it is about 18 degrees to 8 degrees. If you are within this range, you are ok; otherwise your knees may be at risk.
It is quite complex and my recommendation is: if you are having pain, you better go to see Dr. Chan.
And let Dr. Chan check and see if you have this pain syndrome.
Once again, this is called patellofemoral pain syndrome.
Ok, I know you can only show us how to treat this condition or what kind of exercise to do next time.
Thank you. Thank you.