"In anterior suprapatellar fat pad impingement syndrome, the cause is usually due to either a developmental cause related to the anatomy of the extensor mechanism or may be related to abnormal mechanics. In this syndrome, the posterior border of the anterior suprapatellar (quadriceps) fat pad is high signal on PD MRI and convex with a mass effect upon the suprapatellar bursa."
"In infrapatellar fat pad impingement syndrome (Hoffa disease) the cause is usually due to single or repetitive traumatic episodes; the inflamed fat pad then becomes hypertrophied with a predisposition to impingement between the tibia and femur, and thus to further injury (a vicious cycle). Associated findings include patella alta and lateral patellar subluxation."
"In infrapatellar fat pad impingement syndrome (Hoffa disease) the cause is usually due to single or repetitive traumatic episodes; the inflamed fat pad then becomes hypertrophied with a predisposition to impingement between the tibia and femur, and thus to further injury (a vicious cycle). Associated findings include patella alta and lateral patellar subluxation."