Fat pad impingement (Hoffa's Syndrome)

Hoffa's Syndrome

Every knee has a very sensitive tangerine sized piece of fat that sits behind the kneecap tendon called the Hoffa's fat pad. If this becomes inflamed it can be a potent cause of anterior knee pain. 

Once inflamed or swollen it is physically bigger, and it then becomes vulnerable to getting pinched in the knee joint again causing more pain and more swelling. Quickly a vicious cycle can arise with daily pinching swelling and before you know it you have chronic anterior knee pain. 

For some reason, most doctors seem to have no idea about this condition and brand patients as having 'anterior knee pain' without any idea why they have this pain. It is often regarded as being incurable, 'in your head' or something that will get better with random quads exercises alone.

Charles sees this about 200 times a year, and has lots and lots of second and third opinions from around the UK and around the world! 

What are the triggers?


This can be triggered by a single injury with a blow to the knee, or by hyperextension of the knee, or can be part of an overuse injury with repetitive microtrauma to the fat pad. It can also be seen as a consequence of clumsy arthroscopic surgery on occasion.

Common patterns are: 
- females who have stretchy ligaments (ligamentous laxity or hypermobility) whose knees come beyond straight. There may be no history of an injury
- cyclists or runners with biomechanical problems, e.g. poor bike fit, or long stride length 
- professional sports people after an injury to the knee
- failure to improve, or new pain, after knee surgery

What are the symptoms? 

You will feel pain below the kneecap at the front of the knee. It will be most prominent when the knee is fully straight and may be worse with walking or running, but sometimes with the leg straight in bed. There is often pain kneeling. There may be a visible bulge either side of the kneecap tendon in severe cases.
Sitting with the knee flexed, for example, on a flight, or a the cinema can be terrible. Going downstairs can be bad. Running and cycling can be bad. 
If you think you have this injury it is well worth getting it checked out by Mr Willis-Owen. It is often misdiagnosed by non-specialists. 

How is it treated? 

Treatment involves first confirming the diagnosis. Careful examination is all that is needed however an MRI scan can be useful to exclude other problems. Reports are often misleading as most radiologists don't fully recognise the condition either.  Once confirmed treatment can begin. 
Physiotherapy to strengthen the Gluteus Medius muscle, and prevent valgus hyperextension at the knee, as well as anti-inflammatories, are useful and K-taping can help. 
Steroid injections to reduce the inflammation can help break the cycle but need to be administered to exactly the right spot. This can also be really helpfult to prove that iot is the fat pad that is the pain driver. You often need just one injection to cure you, but sometimes a series of injections is needed, or rarely arthroscopic (keyhole) surgery.

What are the results? 

Charles has about a 99% success rate for cure! He has also been through this problem himself…


"Charles; you are the 5th person I have seen about this, travelling around the country to self proclaimed experts. You the only person who has got to the bottom of it an got me back running and cycling. Thank you so much. I thought my sporting days were over until that magic injection.  MG"