Patellar Instability Overview

Patellar instability overview

A lax kneecap is a common disorder, and in the following text and subpages you can learn about this problem. Naturally it is not necessary for you to know everything there is to know in order to get treatment. However if you are a person that want to take responsibility and ask the surgeon, key questions read more.
Symptoms of unstable kneecap

For some patients with kneecap laxity the kneecap will goes out once and they will experience no further problems. Others, however, may go on to experience repeated dislocations. If the kneecap has gone out more than once, it will have a tendency to out again and again. Then things may become quite disabling. The problem can occur while doing activities, like changing direction such as in sport or dancing. For others the kneecap just seems to go out without much provocation. This can happen while walking on uneven or slippery surfaces. In some of the worst cases you need to concentrate on avoiding the kneecap popping out the groove while kneeling. In some it can be a problem while jumping in and out of a car or even during sexual activity. 

Quality of life

Your quality of life can be significantly affected, since a lot of simple daily activities must be avoided. Sometimes your disorder also might cause pain during daily life. It is very important if you are going for surgery to rule out what cause your instabiliy. Your surgery should correct the identified abnormality (or abnormalities, since there may be several factors involved).

Why me?

It is very important to find out why your kneecap dislocated. This is since you can undergo so many treatments and in order for you to have the right one, this have to be examined. This is rather complicated. I have made a site only for explaining this in order for you to ask you surgeon the critical questions - click here

The many myths

Many myths exist about loose kneecap, and one is that you will grow out of it. Mostly this disorder is worse during the teenage years. Then you learn to be more cautious and reduce your level of activity. There is furthermore a tendency for the joint to get less flexible as you age and this helps the kneecap to stay in the groove. So many grownups do not actually grow out of the condition, but they just learn to avoid the activities that provoke the dislocation.

It is just going to be trained away

Another myth is that the disorder just needs to be trained away. This is only partially true. Some may perhaps be able to avoid surgery by learning to use their knee in a more correct way. This can be via physiotherapy and by strengthening the quadriceps and gluteal muscles. A special brace that supports the kneecap can stabilize the patella. There is yet no scientific documentation that say that physiotherapy can prevent further dislocations

Easy to treat - you just need a MPFL reconstruction

The next myth is that surgery can easily treat the disorder. A significant number of patients undergo surgery only to experience that the surgery did not work as intended. As previously mentioned, is of importance to explore the reason why the kneecap dislocates. I suggest that you as a minimum have an MRI can. Then your surgery can be individualized and thereby work efficiently.

It is hereditarily

The next myth is this disorder is inherited. Actually this is true in several cases, and sometimes a dislodged kneecap can be traced back several generations. Especially if you have trochlear dysplasia.

Sorry you surgery did not work

A further myth is that if you had once undergone surgery, and it did not work, that you just need to live with it. Unfortunately this is a disorder where many patient have undergone surgery using an insufficient method. This explains why it did not help or maybe even worsened the situation. Knowledge about this disorder has changed radically over recent years. If the right surgery is done, there is a very good chance for your knee to become significantly better.

What happens when the kneecap dislocate

When the kneecap jumps out it is naturally a very unpleasant experience. Often the kneecap has to be manipulated back at the emergency department. The first time the kneecap dislocates, a ligament on the inner side is torn. This is called the Medial Patellofemoral ligament or just MPFL. Such an injury causes a lot of pain and swelling. Sometimes a fragment of the knee cartilage is loosened. In some cases a loosened piece of cartilage requires surgery to fix the piece back in place or to remove it.

How much will I get troubled?

For those troubled by a continuously loose kneecap there will be a huge variability how much distress this actually causing. However questionnaires have been developed to help both patient and surgeon to elucidate the extent of the problem. Please see an example of a questionnaire here. As previously mentioned is it not always that the kneecap jumps out again. Nevertheless it can still be very troublesome since you may experience that it nearly jumps out. This is called subluxation.

The treatment of loose kneecap

The very first time the kneecap goes out, the treatment is likely to just consist of rest, ice, compression and elevation (RICE). You should be allowed full weightbearing and full range of movement. In past years a brace for support and immobilisation was generally used. Recent research has shown that it does not have any real impact. If the knee does not get the stability wanted and the kneecap continuously is feeling loose, a kneecap stabilizing brace or surgery should be considered. Physiotherapy has also been an important part of the treatment in improving muscle balance. Still we need studies that demonstrate that it has a positive effect. Please read more about surgery here; MPFL reconstruction - Tibia tubercle osteotomy - Trochleoplasty - Rotational osteotomy

The many names for unstable kneecap

The condition of a loose kneecap has many names and here you can learn more about: dislocating kneecap, kneecap out of its groove, kneecap out of its socket, kneecap malalignment, slipped kneecap, jiggly kneecap, unstable kneecap, recurrent patellar instability, episodic patellar instability, luxating patella, unstable patella...

The condition of a loose kneecap has many names and here you can learn more about: Dislocating kneecap, kneecap out of groove, kneecap out of socket, kneecap malalignment, slipped kneecap, jiggly kneecap, unstable kneecap, recurrent patellar instability, episodic patellar instability, luxating patella, unstable patella


In case you would like a second opinion regarding your MRI or just your general knee situation, I do Zoom consultations. The cost is 225 euro.

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Combined surgeries

All the here mentioned surgeries can be combined and sometimes it can be necessary to do both Arthroscopic trochleoplasty, distalization of the tibial tubercle, rotational osteotomy of the femur and tibia and MPFL-reconstruction.