Acute Patella Dislocation

What is it?

The patella (kneecap) normally sits within the groove on the front of the knee which allows it to slide up and down smoothly as the joint bends and straightens. Acute patella dislocation occurs when the kneecap moves sideways and out of this groove.

Who gets it?

In children, acute patella dislocation occurs as a result of accidental injury during sport, play or physical exercise. Often, the injury is linked to a twisting movement or direct blow that causes the dislocation.

How does the injury present?

Change in shape of the knee with pain and swelling are the common signs of dislocation. Often, the patella will relocate (or “reduce”) spontaneously, however occasionally this does not occur and assistance is required at a hospital emergency department.

How is it treated?

After initial x-rays to exclude bony fragments or fractures, a reduction (or relocation) is performed to restore the kneecap to its normal function. Following this, crutches and a knee brace are used for mobility along with a rest, ice, compression, elevation process (otherwise known as a RICE regime) for a period of 24 to 48 hours.

For all first time dislocations an MRI scan is recommended to ensure that there has not been damage to the cartilage of the knee and to look for underlying problems that can lead to further dislocations.

Once the pain has eased, the next step is to engage in physiotherapy in order to strengthen the quadriceps muscles which are associated with the condition. Restoration of strength in these areas is vital to a full recovery.

When can the child return to normal physical activity?

The process of recovery usually takes around 8 to 12 weeks, after which time children are usually pain-free, having regained normal strength in their quadriceps. Should a child experience ongoing patella dislocations, it may be necessary to seek a referral to an Orthopaedic Surgeon.