The infrapatellar (Hoffa’s) fat pad explained

There are various fat pads, but the one at the knee that causes a lot of problems is the infrapatellar fat pad, also known as Hoffa’s fat pad after the man who first described it.

The fat pad has been shown to be very pain sensitive. It is rich with nerve endings that can fire off messages of pain to the brain, and it is therefore of no surprise that people with fat pad problems are often in a lot of pain.

The fat pad is often overlooked, with clinicians concentrating on joint surfaces, cartilage, ligaments and tendons, and dismissing the patient if these structures appear normal on imaging.

So what can go wrong in this funny pad of fat? There are two very different scenarios. The first is mechanical. The fat pad gets a trauma to it. Now this may be an obvious one off blow to the knee, or where the patient straightens their knee at speed and feels an immediate very sharp pain in the fat pad. Or, as is seen more commonly the fat pad may get nipped between the patella and the tibia, and microtrauma leads to a macro problem. In either of these situations it is common to see an inflammatory response. This is a problem as inflammation leads to swelling, and leads to the scenario where the fat pad gets pinched and caught even more. This feeds into a vicious cycle that many patients get completely stuck in. Furthermore, once the fat pad becomes big it alters the way the kneecap moves, and this in turn can lead to high pressure under the patella, which is also often painful.

Can anything be done? Yes! The first is to try and break the vicious cycle of inflammation and swelling. I often recommend ice massage to oiled skin, right on to the fat pad, (the ice-it-away  is really effective for this), and will often tape the kneecap off the fat pad. Wearing a slight heel can help stop the patella knocking onto the fat pad, and most definitely avoiding standing with the knee locked back.

A treating clinician should also be assessing if there are other factors contributing to squashing the fat pad. These may, for example be quadriceps tightness, or poor movement patterns, particularly in people who are hypermobile.

There are also non-mechanical sources of problem in the fat pad, and these should be referred to as metabolic. This is seen with obesity and osteoarthritis of the knee.

Let’s take obesity. When someone is carrying excess fat they will have systemic inflammation. This is one of the reasons for raised cardiovascular risk, but the fat pad becomes inflamed and can hurt. The good news is that weight loss not only reduces load to the knee but also with immediate effect has been shown to reduce the inflammatory state of the knee.

In osteoarthritis it appears that the fat pad changes its state to produce unhelpful pro-inflammatory cells. As the fat pad is housed within the capsule of the knee the fat pad drives further joint breakdown that clearly is undesirable. The good news here is that any efforts to reduce the inflammatory state of the fat pad will have a positive effect on the inflammatory state of the whole knee.

To conclude, as weird as it is, this little pad of fat under the kneecap can be a very painful and persistent source of problem. Make sure you seek the right help to treat the problem, and help you get back to the things you love doing.

If you want to understand this in more depth why not look at my webinar on the fat pad https://t.co/juxILqftIm


kevin 05-01-2016


Claire 09-01-2016

I would always recommend that you have a detailed assessment to see if there is also any biomechanical reason why you are still nipping the fat pad. they are very tricky to treat, but not impossible! Let me know if I can help further.. Good Luck! Caire

Aly 28-01-2016

Can I cure fad pad inflammation with PRP?

Claire 01-02-2016

There is no decent research to suggest you can. In addition, any interventions aimed at treating the fat pad need to consider why the problem came on in the first place. Faulty biomechanics/training/movement patterns etc need to be addressed otherwise the fat pad problem can return. Hope that helps? Claire

wheelchairindia 22-06-2016

Hey, very nice site. I came across this on Google, and I am stoked that I did. I will definitely be coming back here more often. Wish I could add to the conversation and bring a bit more to the table, but am just taking in as much info as I can at the moment. Thanks for sharing. Kneecap Keep Posting:)

Claire 22-06-2016

Thank you for your kind comments! I will keep posting, don't worry! Best wishes Claire

Katie 04-09-2016

Well written and relevant article! Thank you for sharing. Why do you suggest icing over oiled skin? What is the importance of the oil?

Claire 05-09-2016

Hi Katie, It simply helps to protect the skin from an ice burn. Thanks Claire

Frank 10-09-2016

Hi there! This blog post couldn't be written any better! Reading through this post reminds me of my previous roommate! He continually kept talking about this. I am going to send this post to him. Fairly certain he will have a good read. Many thanks for sharing! http://bing.org

Claire 10-09-2016

Thanks Frank! I'm glad you could relate to it and hope your friend finds it useful too.

Eleanor 22-02-2018

Thank you for writing this! I've been struggling with fat pad impingement for about five months now (but it was misdiagnosed for two of those months), and nothing was really working, although taping provided some temporary and imperfect relief. I had an injection of cortisone a couple of weeks ago which was initially extremely painful but has since improved slightly. I've been icing the area, but I will definitely adopt your ice massage recommendation in future. I was just wondering what your opinion is on using ultrasound therapy for fat pad impingement?

Claire 22-02-2018

Hi Eleanor, I'm sure there will be some advocates of US for fat ads, but personally I haven't found it that helpful. Good luck!! best wishes Claire

MJ 27-04-2018

Dear Clair, I am 6 months out from arthroscopic meniscus trim of the lateral compartment but awoke from anesthesia to learn the surgeon decided to “clean up around my synoviumand fat pad”. My symptoms fit all descriptions of medial plica and patellar fat pad irritation. Biggest concern is may have fibrotic changes to medial plica that could damage articular cartilage of my tibia and femur. Do you think infra-articulate cortisone shot is indicated now? Other posts here don’t sound like Cortisone shot was that helpful. Thanks, MJ

Claire 04-05-2018

Hi Sorry to hear you are having a difficult time. I wouldn't proceed to a steroid injection until you have had a go at settling it with physiotherapy. However, if the knee is very swollen the steroid may help accelerate your progress. I hope that helps. best wishes Claire

Christine 20-06-2018

Hi- great site! 9/1/17 I was doing a wall squat, fell severe pain along w cracking sound in knees. Dr said both knees were sprained. Went to Europe for 18 day tour, (no refunds so I was stuck going)... took Aleeve for 3 weeks. 5 mos later- after lots of PT & ice daily still no progress so had MRI which was normal; went to new Dr & PT group who said I have PFS. I am def a little better, but still have pain under medial sides of patella & on sides of patellar tendon. In Feb I could only do 5 min of exercise, now I’m at 35. Stairs & ROM havent beenna prob. Using Voltaren when needed. Will this ever get better? I’m worried that I have permanent damage from my injury...any thoughts?

Karla 10-07-2018

Dear Claire, I used to be a competitive swimmer and have struggeled with chronic fat pad inpingement in both knees for the past 4 years, I am only 16. I have so far had 6 cortisone injections, 1 arthoscope, many physiotherpy rehab programs, acupuncture, medication, orthotics and rest from all activites. I am very hypermobile and this issue started as I was hyperextending my legs whilst kicking in swim training, but has now started to be too painful to straigten my leg in any setting. Out of frustration I had an arthoscope last year, but done by a poor surgeon who did not look properly into the fat pad and did not trim anything. I had to quit swimming around 4 months ago but despite, the pain has stayed the same. I am now considering getting a bilateral fat pad trim, so that I can start to do more intense strengthening programs, as all I can do now is floor bridging. I was wondering what your opinion is on fat pad trim at such a young age and how the sucess and recovery is like? Thank you so much for your help.

Susan nixon 23-07-2018

Hi I recently had arthroscopic surgery, my issue. ifraptellar fat pad odema indicating maltracking with a thickened medial plica , this was shaved down. My question is after this is it normal to have so much popping and cracking in the knee which I never had before , is this a sign of recovery? Thanks

Claire 26-07-2018

Hi Susan It is common to have noises and as long as they are not associated with sharp catches of pain they usually settle down. The most important thing now is to regain your strength but ideally guided by a physiotherapist to max out on strength gains without over stressing your knee as it recovers from surgery. I hope that helps and good luck! BW Claire

Claire 26-07-2018

Sorry you are having such a tough time. I would be very cautious as it is certainly not a quick fix. Have you tried off loading taping of the fat pad, and also lots of control strength work around zero to stop you hyperextending too readily? Have you tried ice massage religiously ie min x1 every day. Good luck with it. BW Claire

Claire 26-07-2018

Hi Christine, Although not pain free you are so much further forwards than you were! This is a great sign.keep going-it can take many months of building up but just keep the upward trend but in really small increments. If the damage was severe it would be less likely to improve like this so I would say stay positive. Good luck! BW Claire

Vincent 01-09-2018

Hi Claire Thanks for all this information! This is really useful. I had an arthroscopic surgery done yesterday. What I initially understood would be an investagory procedure ended up with me waking up to find that my Hoffa Fat Pad had been removed. Would you be able to advise please on what are some of the standard consequences of such a removal? Is there anything I should be mindful of going forward? Thank you in advance.

Claire 03-09-2018

Hi Vincent I hope you are not too sore today. I would be very keen to see the swelling go down. I would use s general ice oack every 2 hours, (if possible with life!) for 10 mins. Once the small wounds are healed I would look to apply ice massage to the fat pad area. I would encourage gentle self movement of the patella in all directions eg 20 secs every 2 hours. Try and see a physio soon if you can to guide you further depending on what they see. I hope that helps. Good luck, Claire

Kyle 05-09-2018

So playing basketball about 8 months ago, I injured this. Pain was minor along with swelling.. didn’t know what the problem was. Waited about 6 months later to get mri, found out there is sweeping around fatty pad. Have done ice a lot, and have tried to do physical therapy as much as I can. Sometimes I go a little to far, and aggravate it. Then it will take a week or two again until I can move properly again. But now, I’ve been pretty good about not pushing it, and seems to slowly be getting better.. should I continue to bike? And swim occasionally, lightly? And ice... with slow therapy will it get better? How do I know if I need surgery?

Claire 06-09-2018

Hi Kyle well done for being patient! You are describing a typical fat pad story! I would definitely bike. With swimming especially crawl just watch you are kicking form the hip and not the knee. The ice-are you doing ice massage? I personally think it's much better than an ice pack. You then need to gradually get stronger but avoid sudden shocks/changes- as you jave found out they can reallu set you back. If you get really stuck I do skype consultations. Just email me to arrange. Good luck! best wishes Claire

Nathan 10-09-2018

Hi Claire I have been having knee pain for more than a year. I have done PT, but with little relief. I recently saw a new OS consultant who diagnosed me with fat pad syndrome, possibly with inflammation of other areas of the soft tissue around the knee. However, the MRI does not showing anything in the fat pad. The OS, given that PT, rest and icing did not produce good results, suggested arthroscopy to trim the inflamed tissues. What is your opinion on arthroscopy for fat pad or in general chronically inflamed soft tissue? Can the chronic inflammation lead quickly to OA?

Claire 13-09-2018

In my opinion it can't lead quickly to OA. I would want to be asking what is perpetuating the inflammation. I definitely would not rush into the surgery, especially as the MRI is inconclusive. If you can't see me re geography I could potentially do a skype consult. I have helped many other patients that way.

Mary 19-09-2018

Hi Claire. Thanks for the info on this blog. What do you think of steroids shots or oral steroids/anti-inflammatories for fat pad irritation? Does any of these work? Is it better to avoid any kind of PT with fat pad inflammation and just rest or are there exercises that can help?

Claire 20-09-2018

Hi Mary In my experience the anti inflamms and steroids don't really work that well, and are at best temporary unless the underlying causes are addressed. these can be addressed with physio as it may be tightness/weakness/poor movement etc. Ice massage is very helpful-see the ice-it-away in my 'shop'. If you draw a blank and are not nearby I do do skype consultations. Just email if you'd like more info. Best wishes Claire

Grace 28-09-2018

Hi, I just had a cortisone shot due to fat pad impingement and I’m very skeptical. How frequently does it actually help people? I’m very concerned that it won’t work and the pain won’t go away.

Claire 09-10-2018

Hi Grace The effect is very variable but sometimes it calms things enough that the rehab is then more possible, and that ultimately gives the long term result. i hope all goes well. If you are still struggling you are more than welcome to see me for a face to face or if that's tricky a skype consult. BW Claire

Donna 17-12-2018

My 17 year old daughter who is a runner is scheduled for partial fat pad excision in January after 8 months of pain and lots of physical therapy including McConnell's taping, 'active' non-irritating rest, icing consistently, voltaren gel, and dry needling with e-stim into the fat pad. Changed running form to avoid overstriding and subsequent impingment. MD stated steroid injection wouldn't be helpful in her case. There are tissue changes to the fat pad noted on MRI. I'm concerned about surgery and don't want to make anything even worse. Suggestions/comments? Thank you.

Claire 19-12-2018

My thoughts would be has anyone established why the fat pad is impinging? Until that is sorted ice, tape etc are unlikely to sort this out. Happy to see her or do a skype consult if it helps. BW Claire

Marina 22-02-2019

Hi Claire, thank you for your blog. I have a fat pad inflammation for more than 1 year now, I did an MRI which accused the problem. I'm a swimmer and injured myself during a trainning set. It would hurt a lot while stretching the leg, doing butterfly kick and pushing the wall. I stopped the sport hoping it would get better. I've done a lot of physical therapy, ice, tapping and it has helped, but still I'm far from beeing 100% healed. Sometimes I think it's getting better but then suddenly, specially when I do some different exercises, it gets worst again. Lately I've also been having pain in the other knee. I'm very worried and thinking about the arthroscopic surgery. Can you tell me how much time would it take to recovery from the surgery?

Claire 26-02-2019

Hi Marina Im afraid my experience if fat pad surgery on the whole is not positive with many worse after than before.Have you done lots of strength work as I view that as essential? BW Claire

TJ 19-03-2019

Hi. Been struggling w/fat pad impingement for 6 months. Cortisone shot in plica didnt help. Ice, PT, rest also not helping. Any advice? Can we facetime or something?

Claire 23-03-2019

I do skype consults for people out of area. Please contact Wimbledon Clinics to book.all details can be found on the 'contact' tab. Thanks Claire

Graham 22-06-2019

Hi Claire, I have had bilateral anterior knee pain R>L for 20 years. After 10 years of soccer and 4 years of cycling I had to stop due to pain, I'm 40 now. 10 years ago I started physio for 6 months with minimal improvement. I had bilateral thickened plicas (on MRI) removed both knees and a cleanup. Not much changed symptom wise. 5 years ago, I found out I had congenital patella maltracking, L 12deg, R 15 degrees. No dislocations though. A different surgeon performed lateral release bilateral and R tibial tubercle transfer. Still have pain. Seen other physios for strength work after that, still have pain. I don't have much swelling but have pain and is at the inferior border of patella, just under the patella tendon. ACL, PCL, Meniscus are all ok. It seems like the fat pad is the only thing left? Penny for your thoughts. Thanks. Graham

Claire 24-06-2019

Hi Graham, Wow you really have been through the mill! It could be fat pad pain.They are certainly very irritable and probably wouldn't improve with any of the surgical treatments you have had. Have your MRI's shown any fat pad oedema. It doesn't mean the pain is definitely from the fat pads but its unlikely to be fat pad pain if they look normal on mri. If it helps you can self refer to see me. People travel from all over. if that doesn't suit I also do skype consults. Good luck wit it all. BW Claire

Amy B 18-09-2019

Hi Claire, I was playing football at a very high level and 2 years ago I ended up with pain in my knee which got progressively worse over preseason it would calm down on my rest days but I would then feel the pain after the session. It then got to the point of being in constant pain and being sidelined and sent for MRI. This showed fat pad impingement and meniscus tear. I then had key hole surgery where they trimmed the meniscus and there was no mention of the fat pad - all focus was out on the meniscus tear being the problem. A few months after surgery I was complaining of the same pain as before if not worse and unable to do rehab for the surgery as every time I exercise I flare up the knee. I had another MRI which confirmed the fat pad was still very much impinged and I was sent for physio and then multiple steroid injections. I was then sent for a surgical opinion as the Injections and physio hadn’t improved the initial swelling - very much caught in a viscous cycle of needing to exercise but even the basic movements flare it up. The surgeon didn’t want to operate and sent me for another MRI (the one I had just had didn’t state evidence of previous surgery and he wasn’t happy with that) and sent me back for more physio. We did more physio with ultra sound and acupuncture and other methods to try and improve the swelling and pain levels. My knee has been constantly taped up for almost a year too. After that still wasn’t helping I was sent to another surgeon with the view to have part or all of the fat pad removed only to be told that they don’t do that as a surgery and I shouldn’t have been advised that and basically it’s one of those things like chronic back pain it’s learning to manage the pain, now I am being sent for ANOTHER MRI and back to the physio. I am at the end of my patience with the whole thing I just want to be able to start recovering and be able to run. I am only 25 and I don’t know how to get out of this cycle I am in, the physios are saying surgery and the surgeons are saying physio I’m stuck in middle wasting months at a time waiting for all the referrals. I am still doing my exercises and using ice and heat and actively trying to improve every day but it isn’t taking the pain or swelling out of the equation, what would you advise my next step should be?

Claire 19-09-2019

Hi Amy What a nightmare-but sadly a story I hear a lot. This going round in circles is exactly what I hear. I cannot see how another MRI is going to help. My question has to be what mechanically is perpetuating the impingement? That is key otherwise you will just go round and round in circles. Forget US there is no evidence to suggest that will help, especially at this stage. Could you get to Wimbledon to see me? If not I can do a skype consult. Finally have you tried ice massage? I find it mpre effective than an ice pack which is why I invented the ice-it-away. Let me know if I can help further. BW Claire

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