Fat pad impingement, also called Hoffa's syndrome, is pain at the front of the knee just below the kneecap. It happens when the fat pad behind the kneecap tendon gets pinched and inflamed, often when the knee straightens fully.
The infrapatellar fat pad, also known as Hoffa's fat pad, is a soft cushion of fatty tissue just below the kneecap, behind the patellar tendon. It has a rich nerve supply, so it can be very sensitive. When the knee straightens fully, or bends backwards beyond straight, the fat pad can be squeezed between the thigh bone and the shin bone. Repeated pinching can make it swollen, inflamed and painful.
Once the fat pad is swollen, it takes up more space and is more easily pinched again, which can keep the problem going. Fat pad pain can be mistaken for patellar tendinopathy, pain behind the kneecap or a meniscus problem, and it may occur alongside these. A careful assessment helps identify the main source of pain so that treatment can be targeted.
The doctor asks about your symptoms and activities, then examines the knee. This includes gently pressing on the fat pad and checking how the knee feels when fully straightened.
Your hip, knee and foot control may be observed while standing, stepping and squatting. This helps find habits or weaknesses that may be loading the fat pad.
Where it helps, an ultrasound scan can look at the fat pad, patellar tendon and nearby bursae. This can help separate fat pad pain from other causes of pain at the front of the knee.
If symptoms persist, or another problem such as a cartilage or meniscus injury is suspected, an X-ray or MRI may be arranged by referral.
Your plan depends on what the assessment finds. These are the options we most often discuss.
Avoiding standing with the knees locked back, and easing off activities that force the knee straight, gives the fat pad a chance to settle.
Taping that lifts and offloads the fat pad, or stops the knee from straightening fully, is often used to ease pain in the early stages.
Learn moreA programme to strengthen the thigh and hip muscles and improve control as the knee straightens may help reduce pinching of the fat pad over time.
Learn moreSimple pain relief or anti-inflammatory medicines, where suitable for you, and cold packs may help ease pain and swelling during a flare.
For pain that has not settled with other measures, an image-guided injection into the fat pad may be considered where assessed as suitable. Evidence is limited, so it is not a first-line option.
Learn moreIf symptoms persist despite a full course of treatment, the clinic will refer you to an orthopaedic surgeon to discuss whether surgery may help.
Fat pad pain often settles over a few weeks to a few months once the pinching is reduced and the fat pad has time to calm down. Because the fat pad is sensitive, progress can be slow at first, and flare-ups may happen if the knee is overloaded again. Recovery times vary from person to person. Many people are able to keep doing some form of exercise throughout, with changes guided by their doctor.
Both cause pain just below the kneecap, so they are easily confused. Tendinopathy is a problem with the tendon itself and tends to hurt with jumping and heavy loading. Fat pad pain is often worse when the knee is fully straightened or after prolonged standing. The two can occur together, and an ultrasound scan may help tell them apart.
Many people stand with their knees pushed back into a locked position, which squeezes the fat pad. Standing with the knees slightly soft and shifting your weight regularly may help. This can make a difference if you stand for long periods at work or while carrying children.
Usually you do not need to stop completely. Activities that force the knee straight or involve a lot of jumping may need to be reduced for a while. Other exercise can often continue with some changes, and your doctor can help you adjust your routine.
Fat pad impingement is usually managed without surgery. Surgery is only considered for a small number of people whose symptoms continue after a full course of treatment. If that applies to you, the clinic will refer you to an orthopaedic surgeon for an opinion.
No. Inflexion Clinic is a private GP clinic, so you can book directly. Book online or call the clinic on +65 8997 0659.
Our clinicians will take a proper history, examine you, and give you a clear plan on the day.