Patellofemoral pain syndrome (PFPS) What is Patellofemoral Pain Syndrome? Patellofemoral Pain Syndrome (PFPS) is pain behind or in front of the patella (knee cap). It is one of the most frequent musculoskeletal conditions of the knee, and can affect all ages, most commonly adolescents and young adults. Prognosis of PFPS is very good, with [...]