Infrapatellar Fat Pad Syndrome
The infrapatellar fat pad is a soft tissue structure that lies just posterior to the patella in what is called the anterior interval. Although, there is no definitive function of the fat pad, it is said to be the buffer for direct forces placed on the anterior knee as well as protect the underlying structures.
When direct force occurs to the patella, pinching of the fat pad between the femoral condyle and/or tibial plateau can result. Due to the increased vascularity and nerve innervation of the fat pad, increased pinching will eventually lead to sharp anterior knee pain.
- Complaints of anterior knee pain
- Clicking/catching reported at the knee
- Positive Hoffa’s test and Patellar tilt test
- Pain with knee extension
- Stair negotiation ascending > descending
- Prolonged period of Flexion
- Extension Block
- Decreased patellar mobility
- Knee/Hip/Ankle AROM/PROM
- Patellar mobility
- Quadricep Strength
- Gluteal Strength
- Squatting, gait, single limb balance, daily work/sport specific tasks
Physical therapy to address; hip/knee/ankle range of motion, Quad*/Gluteus retraining, gait training, functional lower extremity mechanics in closed chain, pain reduction with soft tissue management and modalities as needed. Taping may be used to offload the inferior pole of the patella and allow for decreased pinching or pressure on the fat pad
*It is important to adjust quadricep exercises to effectively strengthen through pain free motion, as typical fat pad syndrome presents with pain in full knee extension when in open chain. Thus, lending to a more closed chain biased exercise regime.
Surgical Intervention (if conservative treatment is not effective):
- Fat Pad excision- All or partial of the fat pad is removed as to offload the pain
- Debridement of Fibrosis on/near Fat pad
- Anterior Interval Release
- Infrapatellar plica release
- Denervation of the inferior pole of the patella
Reference: Dragoo, JL, Johnson, C and McConnell, J. “Evaluation and Treatment of Disorders of the Infrapatellar Fat Pad.” Sports med 2012: 42; 51-67.