Many knee problems can be diagnosed from the story of the initiating incident together with a competent examination. Usually those additional special investigations - such as X-ray and MRI scan - serve only to confirm what is already suspected.
With the advent of the internet, people with medical problems find themselves turning more and more to this medium to get an idea of what their problem is, before they approach their doctor. However, it can be a confusing place for the beginner until they get an idea of the range ofdisorders into which their symptoms might slot.
This list will offer some pointers to help people with their researching, 'sign-posting' them to likely possibilities without being proscriptive about exactly what their diagnosis is.
A common maxim in medicine is that'common disorders occur commonly'. It may be that your own disorder is uncommon and not listed here, but these lists refer to common knee problems and symptoms.
At the very least, you should have some idea of the proper terminology which is so important when you are researching online. There is nothing more frustrating than trying to find out more about your own medical problem when you have no idea of the correct words to put into the search bar
One of the first questions that a knee surgeon or physiotherapist might ask at your first consultation is "Did you have an injury?" This is generally the case irrespective of those symptoms that you are experiencing. The kinds of problems that follow an injury are generally very different from those that come on without any precipitating incident.
The cruciate ligaments are stabilising ligaments right in the middle of the knee. The menisci are shock absorbers that also help with stabilisation.
When there has been no injury the person may not be altogether sure about when and how the pain began. Of course there are many possible sites and causes of knee pain coming on without injury - muscle or tendon sprain,inflammatory conditions, arthritic conditions - but these are the commononest.
I think you can see from this that the cause of knee pain has to be teased out with careful questioning and examination, as there are many separate structures that may be giving rise to the pain.
The knee can make several kinds of noises - some are important and some are not of much consequence - but patients obviously imagine that something serious is going on.
Most often knee noises are less dramatic, and if you put your hand on your knee you can also 'feel' the noise. These noises may not be there all the time but may come on when the knee has been stressed, perhaps by some uncommon activity. Sometimes they are heard only in response to certain activities such as going down stairs or squatting.
To understand knee swelling, you need to know a little bit about the anatomy of the knee. Surrounding the joint cavity is a waterproof capsule,which can become like a balloon if the cavity fills suddenly with blood from a torn blood vessel. Then in addition, outside of this main cavity are several little waterproof envelopes called 'bursae', which normally are flattened and help to facilitate movement of the various tissues over one another when the knee moves. If one is damaged, then it can fill with fluid - either clear fluid secreted into the joint or even blood, and sometimes these can become infected. The common one everyone knows about is 'housemaid's knee',where the bursa in front of the kneecap gets traumatised by kneeling. Bursa swelling is very discrete - like a little ball - and can look really odd. Finally,there may be swelling in the tissues around the knee if the capsule has been torn, and this kind of diffuse swelling has a boggy look and feel.
Instability of the knee implies that it cannot be trusted. The whole joint may feel unstable so much so that stepping off the kerb can be frightening, or the kneecap may be unstable, jumping out of its underlying groove. I am going to put into this group also loose structures that can catch inside the joint.
You may be walking along quite happily when something 'catches' painfully right inside the joint. This may be a loose piece of joint cartilage or meniscus,or a plica, which suddenly gets caught between the bones. A loose piece of cartilage would be called a 'loose body'.
Giving way is similar to catching, but the sudden incident causes the muscles to be briefly inhibited and the knee collapses.
Locking is when the knee cannot fully straighten because there is something in the joint which is temporarily preventing this. The common cause is a longitudinal tear in a meniscus - it can be from a new injury or an old one - and a sliver of meniscus gets flipped over to the wrong side of the rounded end of the femur. It may unlock on its own or it may require help from a surgeon, possibly under sedation or anaesthesia. This kind of tear is called a 'bucket-handle' tear.
This is specifically referring to the kneecap, where it partially de-rails but then it returns to the groove in which it normally lies. It may happen occasionally or may be habitual.
The cause may be related to an injury with damage to the ligaments that usually stabilise the knee, or there may be a structural abnormality of the kneecap or its underlying groove.
In this context I am referring to a dislocation of the kneecap, where it jumps right out of the groove and does not return by itself but requires intervention.The term dislocation can also refer to a catastrophic disruption of the knee ligaments holding the long bones together, but that is not something for a little primer like this.
Dislocation of the kneecap can happen just once, or it can become recurrent,and the causes are the same as with subluxation. In particular a structural abnormality of the groove - trochlear dysplasia - needs to be considered, as well as the alignment and possible rotational abnormality of the long bones.
This list is not comprehensive - it is a guide of the common symptoms for common conditions.
If you need help with your knee, and want to talk to others with similar problems, register for free on the KNEEguru bulletin board. Hundreds are people are chatting there every day!