Fat pad impingement of the knee is a common cause of pain at the front of the knee. We should differentiate this condition from other causes such as patellar tendonitis or kneecap arthritis. So, how do we correctly diagnose fat pad impingement and what can we do about it?

What is the fat pad of the knee? 

The fat pads are found at the front of the knee just behind the patellar tendon and kneecap. Many doctors call them Hoffa’s fat pads. We think the fat pads act as shock absorbers during knee movement. Interestingly, the fat pads are the most sensitive structures in the knee containing a high number of sensitive nerves.

Cause of fat pad impingement

fat pad impingement

Generally, we think that too much activity or sport can cause pinching of the Hoffa’s fat pads between the knee cap and the femoral condyles. This pinching causes low-grade damage to the fat pads leading to inflammation and scar tissue.

Usually, fat pad inflammation occurs with other knee conditions such as arthritis, patellar tendonitis, and meniscal tears. However, there are other reasons for pinching of the fat pads include playing sports or a direct fall onto the knee.

Fat pad syndrome symptoms 

In general, typical complaints of fat pad syndrome include pain directly on the fat pads on either side of the kneecap and focal swelling. It is important to rule out other causes of pain at the front of the knee such as patellar tendonitis or kneecap arthritis.

In some cases, imaging is needed to confirm the diagnosis. Often, we use ultrasound or MRI to look at the front of the knee. Usually, in Hoffa’s fat pad impingement, we see swelling in the fat pads on MRI or high blood flow on ultrasound.

How do we treat Hoffa’s fat pad impingement?

brace for knee arthritis

Usually, we start with simple treatments. These treatments include exercise therapy to reduce the forces on the fat pads, leg stretching to reduce tightness, and taping or bracing the knee.  Other effective treatments include shoe modification or orthotics and soft tissue massage.

Fat pad impingement taping

Often, people find fat pad taping useful to reduce pain from fat pad impingement. Generally, we use three pieces of tape – one on the top part, one on the inside, and one on the outside of the patella. The taping forms a V shape that reduces pressure on the fat pad.

fat pad taping in male

Is fat pad injection an option? 

Yes but only in a small number of cases that fail simple treatments. Usually, your doctor will direct a small dose of cortisone into the fat pad to reduce swelling. Fat pad injections are best done with the help of ultrasound to improve accuracy and reduce side effects. Reducing pain will help in the positive effects of exercise therapy. However, you need to be careful as cortisone injection has significant side effects. You should ask your doctor about the side effects when considering a fat pad injection.

In cases resistant to cortisone, we consider PRP injections for fat pad impingement.

Is Hoffa’s fat pad surgery successful?

Surgery such as fat pad removal should be avoided and only used as an absolute last resort. Keyhole surgery is unpredictable and some cases do worse after Hoffa’s fat pad surgery.

Final word from Sportdoctorlondon

Fat pad impingement is a common cause of pain at the front of the knee. We always recommend simple treatments first. In difficult fat pad impingement cases, we suggest you speak to your doctor about a cortisone injection to help with rehab.

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Dr. Masci is a specialist sport doctor in London. 

He specialises in muscle, tendon and joint injuries.

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