Anterior knee pain
Anterior knee pain is a very common complaint and the most common diagnosis is that of patellofemoral joint pain syndrome (PFJPS), which may affect up to 25% of the population at some stage.
The differential diagnoses of anterior knee pain include patella tendinopathy, osteochondritis dissecans (OCD), osteoarthritis, plica syndrome, fat pad impingement and, in children, Osgood-Schlatter’s syndrome.
Patellofemoral pain is thought to be due to a lateral mal-tracking of the patella in the femoral trochlea.
It is initiated either by a single bout of excessive exercise (e.g. a whole day bushwalking over hills), or a more low grade but repetitive overload (e.g. a new running program).
The key factor causing mal-tracking is weakness of the vastus medialis obliquus (VMO), which is the main dynamic stabiliser of the patella