Infrapatellar fat pad syndrome
Infrapatellar fat pad syndrome, or impingement, is a common injury that affects the front of the knee. It is often referred to as Hoffa’s disease or hoffitis named after the man who first reported the syndrome in 1904 Dr Albert Hoffa.
The structures involved with infrapatellar fat pad syndrome are the Patella, Femur, tibia, Quadriceps tendon, Patella tendon and the infrapatellar fat pad.
The infrapatellar fat pad is found between the femur and tibia of the knee (at the back) and the patella (kneecap) and patella tendon (at the front).
The fat pad is a structure that sits within the joint capsule, but outside the motor fluid or synovial region. It is believed that the fat pad decreases the loading of the patellar on the femur reducing the early onset of osteoarthritis and patella tendinopathies.
It moves according to the positioning of the knee, in a knee bent position the top outer portion is relaxed and moves backwards, when the knee is extended it lies between the outside of the patella and the quadriceps tendon.
Causes of fad pad inflammation include:
- Direct trauma
- Poor patellofemoral alignment (kneecap tracking)
- Too much hyperextension through the knee range
- Poor lumbopelvic stability
It is due to where the fat pad sits, especially with the knee extended that is the main cause of pain and impingement. In this position it is easy for the fat pad to become pinched or impinged between the patella and the femur resulting in inflammation and pain. With more severe cases, where there is significant inflammation, the bent knee can still compress the inflamed pad between the anterior femur and patella tendon.
Injury and inflammation to the fat pad occurs either due to direct trauma, hyperextension injury or a chronic irritation. As a result, the bottom tip of the patella can pinch the fat pad onto the femur. Over time, if not treated and continued repetitive trauma occurs this may lead to hypertrophy (increased size) of the tissue and later ossification (bone formation).
The main risk factors for fat pad syndrome include:
- Jumping sports – forcing the knee into extension
- Running downhill – knee can be flicked into hyperextension
- Ligamentous laxity or instability through the knee
- Higher prevalence in women
Symptoms of fat pad pain include:
- Pain through the front of the knee
- Pain with knee extension or hyperextension
- Pain on kicking or squatting
- Pain when kneeling
- Swelling below the kneecap
- Pain with prolonged walking
In most cases fat pad syndrome can be treated in a conservative manner. This includes, initially reducing the pain and inflammation using unloading taping, muscle release and patellar mobilisations to restore full range of knee extension. This is followed by a progressive strengthening program to build stability and support around the knee and minimise the risk of recurrence.
4 tips you can employ to minimise the risk of the injury occurring on the first place:
1. Maintain good flexibility around the knee, especially through the ITB, lateral quadriceps muscle and TFL – Hint a foam roller will come in handy to achieve this.
2. Maintain strength and stability around the knee, especially through the quadriceps and hamstring muscle groups to ensure correct tracking of the patella and reduce the risk of accidentally forcing the knee into a hyper-extended position.
3. Maintain good lumbopelvic stability and hip control, especially when running. Hint – work on those gluteus medius and minimus muscles.
4. As always, make sure you wear footwear with appropriate arch support.
So that’s a brief overview of how infrapatellar fat pad syndrome or impingement occurs, If you have any questions or comments please e-mail us at
email@example.com and we will be happy to answer them for you.
If you suffer from a pinching pain through the front of the knee when you walk, squat, or kneel, feel free to call us on (08) 9486 8653 and our therapists will be happy to chat with you.