Fat pad hypertrophy/impingement (Hoffa’s disease)

Inferior patellar pole traction apophysitis (Sinding-Larsen disease)

Patellofemoral pain syndrome

Osgood-Schlatter disease

Osteochondritis dissecans

Patellar or quadriceps tendonitis

Patellar stress fracture

Prepatellar or infrapatellar bursitis

Referred pain