Hoffa's fat pad impingement in the knee

What is fat pad impingement?

Fat pad impingement, sometimes called Hoffa’s syndrome, is irritation of a soft cushion of fatty tissue that sits just behind the patellar tendon and below the kneecap. This tissue is rich in nerve endings, so when it becomes pinched, swollen or inflamed — often after a direct injury, repeated overextension of the knee, or overuse — it can be a source of pain at the front of the knee.

Signs and symptoms

• Pain at the front of the knee, just below the kneecap

• Pain that is worse when the knee is fully straightened or pushed back

• Tenderness and sometimes swelling on either side of the patellar tendon

• Discomfort with prolonged standing or activity

How is it diagnosed?

Diagnosis is largely clinical, based on the history and an examination that reproduces the pain. An MRI scan may be used to confirm inflammation of the fat pad and to rule out other causes of anterior knee pain.

Treatment options

The large majority of cases settle with non-surgical treatment. This includes activity modification, physiotherapy to correct the mechanics that overload the fat pad (including kneecap tracking and avoiding hyperextension), and measures to reduce inflammation. Where symptoms are persistent and clearly localised despite thorough non-surgical treatment, an injection or, rarely, keyhole surgery to address the impinging tissue may be considered.

Outlook

Most children and adolescents recover fully with non-surgical treatment, though it can take time (up to a year) and consistent rehabilitation.

When to seek advice

If your child has persistent pain at the front of the knee, particularly when straightening it, that is not settling.

This information is for general guidance only and is not a substitute for a consultation with Mr Wadia. If you are worried about your child, please seek medical advice.