Patellofemoral Dislocation

The patella (kneecap) sits in the groove at the end of the femur. It usually moves very smoothly up and down in this groove. Sometimes, it moves too far to the side of the knee and slides out of the groove. This is called a dislocation. This can be caused by trauma, like a fall, twist or direct blow, or can happen at random. It can also be caused by muscle weakness from another diagnosis or problem.  

When the patella slips out of place, it can cause a lot of pain. It may move back into place on its own. A patella dislocation can cause damage to the ligaments that hold the patella in place. It is important to see an orthopedic provider after a patella dislocation. They will look for any damage to the ligaments or cartilage.

Signs and Symptoms

• Feeling of the kneecap shifting
• Pain
• Swelling
• Hearing a pop
• Knee looks out of place (deformed)

Increased Risk

There are some things that may make your child more likely to have patellar instability or a patellar dislocation. These include:

• Having other patellar dislocations
• Miserable malalignment syndrome
• Body structure
• Ligament laxity disorders

Treatment and Surgery

Most patients go to the emergency department (ED) or orthopedic clinic due to severe swelling and knee pain. X-rays will be done to check for an injury. If X-rays do not give a clear enough picture, your child may need an MRI. 

Non-surgical treatment: If the X-rays show no fracture (break), your child will be put in a knee brace. For a first-time patella dislocation with no clear cartilage damage, your child usually just needs a brace and physical therapy (PT). Surgery may be needed in other cases.

Surgery: If your child needs surgery, it is usually done within a few weeks after their injury. The orthopedic surgeon will explain the best option for your child. The surgery is often done as an outpatient. Sometimes, your child will be admitted to the hospital. After surgery, your child’s incision will have a bandage over it. They will most likely be in a brace or cast, and on crutches or use a walker for 4 to 6 weeks.

Your child’s follow-up appointment will be 7 to 10 days after surgery. The provider will help set your child up to start physical therapy. This will help increase range of motion and strength in the knee. It is important that you and your child follow all instructions and perform the home exercise program given to you by your orthopedic provider or physical therapist.

When to Call the Health Care Provider

Follow the instructions given to you at the hospital on how to care for the skin. If you see any of the signs of infection listed below, call your orthopedic or other health care provider:

• An increase in pain, redness or drainage, swelling
• Pain that is not controlled by oral medications
• Temperature of 101^○ F (38.3^○ C), especially with other symptoms present
• Nausea, vomiting

Activity

Your child’s health care provider will talk to you about the activities your child cannot do or needs to limit. Have your child limit running, jumping and doing contact activities for at least 3 months from the time of the injury, or until they are cleared by their provider. Your child should only do low energy activities. These activities will be reviewed with you and your child by your provider.

Your child cannot participate in sports or gym class until cleared by the provider.

Follow-up Appointments

• Your child's follow-up appointment is on (date) ___________ at (time)________ in the (place) __________________________________________________.
• Write down all your questions as you think of them. Bring that list with you when you see the health care provider
• Call your health care provider if you cannot keep the appointment.

Patellofemoral Dislocation (PDF)

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