What is Fat Pad Impingement?

Fat pad impingement, also known as Hoffa’s fat pad syndrome, occurs when the infrapatellar fat pad (a soft tissue structure beneath the kneecap) becomes irritated, inflamed, or pinched between the femur and tibia. It is a common cause of anterior knee pain.

What happens in Fat Pad Impingement?

The fat pad becomes swollen and painful when compressed or irritated, often due to trauma, overuse, or hyperextension of the knee. Pain is usually located deep at the front of the knee, just below the kneecap.

Common causes

  • Direct trauma to the front of the knee
  • Repetitive hyperextension movements
  • Overuse from running and jumping
  • Previous knee surgery leading to scarring or altered biomechanics
  • Patellar maltracking increases compression of the fat pad

Who is most affected?

  • Athletes in jumping and kicking sports (netball, basketball, football, AFL)
  • Dancers and gymnasts with frequent hyperextension
  • People with patellar maltracking or instability
  • In Australia, fat pad impingement is a common anterior knee complaint in adolescent athletes

Symptoms of Fat Pad Impingement

  • Deep, aching pain below and around the kneecap
  • Pain is worse with knee extension and hyperextension
  • Swelling and fullness at the front of the knee
  • Kneeling is often very painful
  • Tenderness around the patellar tendon

📞 If you experience sharp anterior knee pain with swelling, book an assessment at Spinal and Sports Care Bella Vista or Parramatta.

Diagnosis of Fat Pad Impingement

Clinical Tests:

  • Hoffa’s test (pain reproduced with knee extension and compression)
  • Observation of swelling and tenderness around the fat pad

Imaging:

  • MRI: Best to confirm inflammation and exclude other causes of knee pain
  • Ultrasound: Can also show swelling or impingement

Treatment options

Fat pad impingement usually responds well to conservative treatment.

Non-surgical:

  • Rest and activity modification
  • Ice and anti-inflammatory management
  • Physiotherapy for taping to unload the fat pad
  • Strengthening of quadriceps, hips, and glutes to reduce patellar maltracking
  • Soft tissue techniques for surrounding structures

Surgical:

  • Rare, considered only in severe chronic cases, may involve partial fat pad excision

Role of physiotherapy

  • Use taping techniques to offload the fat pad and reduce pain
  • Strengthen hips, quads, and glutes to improve biomechanics
  • Educate on modifying training loads
  • Guide a gradual return-to-sport program

Recovery timeline

  • Mild cases: 4–6 weeks
  • Moderate: 6–12 weeks
  • Chronic cases: 3–6 months

Injury grading

  • Mild: Occasional pain with knee extension
  • Moderate: Frequent pain with sports and daily activities
  • Severe: Persistent pain with swelling, limiting kneeling and running

Prevention of Fat Pad Impingement

  • Avoid repetitive hyperextension
  • Strengthen quads, hips, and glutes
  • Correct patellar tracking issues
  • Use proper footwear and running technique
  • Avoid overtraining without rest

Taping and bracing

  • McConnell taping is commonly used to unload the fat pad
  • Knee sleeves may reduce swelling and provide comfort

When to see a physiotherapist or chiropractor

📞 If anterior knee pain persists beyond 2 weeks, particularly with swelling and kneeling discomfort, book an assessment at Spinal and Sports Care.

Frequently Asked Questions

Anterior knee pain caused by irritation of Hoffa’s fat pad under the kneecap.

Common in young athletes, especially in netball, AFL, and basketball.

Jumping, kicking, and sports with frequent hyperextension.

Yes, most cases resolve with physiotherapy and activity modification.

Taping, strengthening, and load modification are most effective.

Rarely, only in chronic cases unresponsive to conservative care.

Ranges from 4 weeks in mild cases to 3–6 months in chronic cases.

Not directly, but chronic anterior knee pain can alter movement patterns and contribute to long-term issues.

Yes, unloading taping techniques can provide immediate relief.

If pain persists beyond 2 weeks and interferes with sport or daily activities.