Dislocated kneecap (dislocated patella) Popoki pakoki

A dislocated kneecap is a common sports injury. It mostly happens in young, active people.

A dislocated kneecap usually happens when:

• you twist awkwardly
• something directly hits your knee when it is bent.

You may feel a popping sensation as your kneecap slips out of its groove.

Sometimes, the kneecap slips back into place by itself. And sometimes a small piece of bone breaks off. If that happens, your knee will usually swell up very quickly.

Even if your kneecap slips back into place, it is important to see a healthcare provider for treatment.

You may have a dislocated kneecap if:

• you feel severe pain at the front of the knee
• your knee looks misshapen or out of place
• there is swelling in the area
• you have difficulty straightening or moving your leg
• your knee feels unstable.

Once your kneecap has dislocated, it may become unstable and dislocate more easily in the future. This can cause problems when playing sport. You can use a neoprene knee brace or strapping to help your knee feel more stable. But you might need surgery to stabilise your kneecap.

You will usually be fitted with a brace to stabilise your kneecap. You will need to wear this most of the time for 3 to 6 weeks.

For the first few days:

• raise your leg, above heart height, using a pillow
• apply ice (or frozen peas) wrapped in a tea towel for 10 to 15 minutes, 4 times a day.

Most people can walk on their leg and bend their knee while they are healing. It may feel wobbly, and you may have some discomfort. Walking and standing are fine as long as it is not too painful. If it is very painful, stop and see your healthcare provider

Your healthcare provider may tell you not to put any weight at all on your leg until you have had further tests, such as an MRI scan. If this happens, your healthcare provider will show you how to use crutches and keep weight off your leg.

MRI (magnetic resonance imaging)

Using a pair of crutches

If your kneecap does not slip back into place by itself, it will need to be put back by a healthcare provider or paramedic. They can give you laughing gas (nitrous oxide) for pain relief when they do. It can be done before you have an x-ray. Your knee will probably feel much more comfortable when your kneecap is back in place.

Once your kneecap is back in place, you will have an x-ray to check if it is broken anywhere.

If this is the first time your kneecap has dislocated, you probably will not need surgery unless:

• a piece of bone needs to be taken out
• your knee has another injury.

Exercises

A physiotherapist can give you exercises to strengthen your thigh muscles (quadriceps), core (tummy muscles) and hip abductor muscles.

The aim is to prevent your kneecap dislocating again by stopping your knee from aligning badly (called knee valgus) and get you back to your normal activity level.

You can find a physiotherapist on HealthPoint.

Physiotherapy services — HealthPoint

If you need surgery for your kneecap, your healthcare provider will refer you to an orthopaedic surgeon.

ACC may be able to help you after your injury.