Patellofemoral Pain : Where does the pain come from?

My thesis is about patellofemoral pain (PFP), a common knee complaint among physically active young individuals. It is also known as ’anterior knee pain’, ’retropatellar chondropathy’ or more recently suggested ‘theatre or moviegoers knee’. PFP is characterized by retropatellar pain (behind the kneecap) or peripatellar pain (around the kneecap), specifically during knee loading activities, like running, cycling, squatting, stair climbing, and/or during prolonged sitting with the knees flexed in 90 degrees. The majority of people with PFP are treated conservatively with exercise therapy, but the effect of exercise therapy is still unknown. Therefore, this thesis assessed the effects of exercise therapy and aimed to point out the most effective exercise strategy. However, despite the application of a variety of treatment modalities, a substantial group of patients has persistent complaints. The pathophysiology of PFP is considered to be multifactorial, but still widely unknown. Therefore, emphasis has been placed on unraveling the pathophysiology of PFP with advanced MRI techniques. For years it has been suggested that cartilage plays an important role, but this thesis suggests otherwise. Furthermore, an innovative MRI method was developed to study blood perfusion of the patella. It might be that vascular problems are present in patients with knee pain during watching a movie or visiting the theatre in particular. Or maybe, there are no differences between patients and control subjects on MRI, but only differences in pain perception as has been suggested previously.......