Patellar Instability

CONDITION:

Patellar Instability (Dislocations, Subluxations)

Patellar instability means any problem that can cause your knee cap ("patella") to dislocate, or slip out of socket. The patella is probably the bone that is the most commonly dislocated in the body.

Dislocation of the patella is very common. It is particularly common in teenagers and women (although not uncommon in men as well). There are different ways to classify this problem.

Classification by trauma

• Traumatic. This means that there was some kind of accident that caused this problem. For example, a sudden twisting of the knee caused the kneecap to come out of socket. This is common in women and men. Usually, a ligament is torn when this happens. Sometimes the ligament never completely heals back properly, and people have recurring problems.
• Atraumatic. In this case, there was no specific injury before the kneecap started coming out of socket. This is the type of instability that is more common in women. This can happen because the person is "loose-jointed". Note: you can be loose-jointed in your knees and not anywhere else. Also, another common problem is that the kneecap is misaligned (i.e., tilted or shifted) and that puts you at risk for instability.

Classification by amount of instability

There is a wide range of patellar instability, including:

• Pain only. When the kneecap is "trying" to dislocate, but never actually does it, sometimes it can just cause pain around the kneecap (similar to chondromalacia). This can sometimes be described by doctors as "excess lateral pressure syndrome" or "lateral tracking". The pain is usually on the outside of the kneecap, and often it is tender to the touch in this area. Sometimes the pain is made better by pushing the kneecap inwards with your finger. Sometimes taping the kneecap in this position can help with the pain (many athletic trainers will do this for their athletes on occasion; unfortunately it is just a temporary cure).
• Subluxations. This means that the kneecap manages to get out of the socket partially, then comes right back into place. Often people will complain of pain and clicking. These people will often feel their kneecap shift around as well.
• Dislocations. This is the most severe form of patellar instability. The kneecap pops out of socket (usually laterally, or to the outside) and gets stuck out there. The first time this happens, many people end up going to the hospital to have it put back in place. If it becomes a recurring problem, often these people learn how to put it back in place themselves.

TREATMENT:

There are several important methods of treating kneecap dislocations and other instability problems. The treatment is different depending on whether the problem happened for the first time, or is a recurring problem.

Traumatic, first time dislocation

This treatment should always be performed under the advice of your health care professional and only represents an example of what typical treatment, in this case, would be.

• Control swelling and pain. The first time a kneecap dislocates is often very painful. Swelling is usually significant for 1 week or more. Cryotherapy is particularly useful in treating this pain and swelling.
• Control knee motion to provide the knee ligaments a chance to heal. Often, if you go to the emergency room, you will be given a knee immobilizer first. Then, a knee range of motion brace, such as the DonJoy IROM or DonJoy Telescoping TROM, will usually be prescribed.
• Rehabilitation is then necessary to help regain strength.
• A patella-supporting knee brace is often useful to provide gentle stability for your kneecap as you return back to your normal activities. The DonJoy Lateral "J" Brace is perhaps the most prescribed brace of this type, and is quite economical. In our own orthopedic surgery practice, we used to recommend this brace exclusively to anyone who has knee cap dislocations. We've since added another knee support — our premier patellar brace — the DonJoy Tru-Pull Advanced Patellar Knee Brace. If you feel you need a little more knee support, then you might like the DonJoy Tru-Pull Advanced Hinged Patellar Knee Brace, which is just like our premier Tru-Pull Advanced, with lightweight hinges to provide additional stability.

Atraumatic/recurrent dislocations, subluxations or pain

Usually these happen because of a malalignment of your kneecap, or because the ligaments have gotten stretched from previous dislocations/subluxations.

• Appropriate bracing to prevent these dislocations. Even if it is not very painful, allowing your knee to continue to dislocate can put you at significant risk for arthritis. The DonJoy Lateral "J" Brace has been designed specifically to prevent lateral (kneecap goes out to the outside) knee subluxations and dislocations, as well as relieve pain caused by lateral tracking.
• Rehabilitation to strengthen the knee. Quadriceps strengthening, especially a part of the quadriceps known as the "VMO" is critical to prevent these problems from recurring.
• Protect the cartilage of the knee. Every time the patella goes out of socket, a little cartilage is scraped off. Unfortunately, there is no way to regrow this lost cartilage. Therefore, you want to to everything possible to maintain the health of your cartilage. Glucosamine sulfate, as found in our JointBuilder, has been scientifically shown to help people with cartilage problems.