Experiencing pain at the front of your knee, or anterior knee pain can stem from a variety of causes. These often involve conditions like patellofemoral pain, Patella tendonitis, Osgood Schlatter disease, bursitis, and tendon ruptures.
Medically reviewed by Dr Chaminda Goonetilleke, 14th Dec. 2021
Gradual Onset of Anterior Knee Pain
Most anterior knee pain develops gradually due to overuse, with no specific incident marking the start of the discomfort.
Patellofemoral Pain Syndrome
Patellofemoral pain syndrome refers to pain stemming from the patella, or kneecap, rubbing against the bone underneath.
Identifiable symptoms include:
- Inner patella tenderness
- Possible swelling
- Increased pain during uphill and downhill walking or after prolonged sitting
Read more on Patellofemoral Pain Syndrome
Jumper’s Knee/Patella Tendinopathy
Jumper’s knee, also known as patellar tendinopathy, is an overuse injury resulting in pain at the bottom of the kneecap. The patella tendon may undergo degenerative changes due to excessive running or jumping.
Look for symptoms like:
- Tenderness at the bottom of the patella
- A possibly enlarged patella tendon
- Post-exercise aching and stiffness
- Progressing to a chronic issue if left untreated
Osgood Schlatter’s Disease
A prevalent source of anterior knee pain in children aged 10-15 years old is Osgood Schlatter’s disease.
Key signs of this condition are:
- Pain at the top of the shin, just below the kneecap, which becomes swollen and inflamed
- Exercise-induced worsening of symptoms, alleviated by rest
- Natural resolution as the child grows, though injury management is essential
Read more on Osgood Schlatter Disease
Sinding-Larsen-Johansson Lesion
Sinding-Larsen-Johansson lesion, or syndrome, typically affects young athletes and children, causing pain at the front of the knee, at the lowest point of the kneecap.
Symptoms resemble those of Jumper’s knee/Patellar tendonitis:
- Tenderness at the bottom of the kneecap
- Pain increases during and after exercise
Chondromalacia Patella
Chondromalacia patella involves damage to the articular cartilage beneath the patella, yielding symptoms similar to those of patellofemoral pain.
Look out for:
- Swelling and pain due to the kneecap rubbing against the bone
- Intensified pain when walking downstairs or after sitting for long periods
- A grinding or clicking feeling in the knee
Anterior Knee pain from Bursitis
Housemaid’s knee, or knee bursitis, involves the swelling of the bursa at the front of the knee. The bursa is a small fluid-filled sac aiding in the smooth movement between tendons and bone.
Symptoms include:
- Pain and tenderness at the front of the kneecap
- Localised swelling or a lump over the patella
- A warm sensation in the kneecap
- Pain when kneeling
Infrapatellar bursitis occurs when the bursa below the kneecap becomes inflamed. Pain at the front of the knee and swelling are primary symptoms, similar to those of Jumper’s knee.
Synovial Plica
The synovial plica, a fold situated on the kneecap’s inner side, can trigger pain and discomfort.
Its symptoms often mimic those of patellofemoral pain syndrome, which includes:
- Sharp anterior knee pain, particularly at the front inside edge of the kneecap
- Pain towards the back of the patella
- Sharp pain when squatting
- A thickened band feeling under the inside of the kneecap
Patellofemoral Instability
Patellofemoral instability can result from various anatomical or genetic causes, or from a previous patella dislocation injury. It is characterised by a loose kneecap sensation, accompanied by swelling and pain at the front of the knee.
Quadriceps Tendinopathy
Overuse may lead to degenerative changes in the quadriceps muscle’s tendon at the top of the patella.
Key symptoms include:
- Pain around the top of the kneecap, intensifying during and after exercise
- Pain when performing a deep squat
- Tenderness at the top of the knee
Fat Pad Impingement
The infrapatellar fat pad, or Hoffa’s pad, can become impinged, often due to a direct impact that traps the pad between the patella and femur (thigh bone).
Symptoms include:
- Tenderness at the bottom and under the kneecap
- Swelling
- Protruding or outward tilting patella
Sudden Onset (Acute) Anterior Knee Pain
Sudden or acute pain at the front of the knee can result from:
Patella Tendon Rupture
A patella tendon rupture is a tear in the patella ligament, connecting the kneecap to the shin’s front.
Symptoms consist of:
- Severe pain
- An audible pop at the time of injury
- Swelling, especially at the patella’s bottom
- Possible inability to bear weight or straighten the leg
Other Anterior Knee Pain Causes
Additional sources of pain at the front of the kneecap could include:
- Pain referred from the hip or lumbar spine
- Osteochondritis dissecans
- Slipped capital femoral epiphysis
- Tumours, especially in young athletes
