Patellofemoral pain syndrome (anterior knee pain) is very common in the general population. It is more often anticipated in teenage girls and young women and generally in young people who are very physically active in competitive and recreational sports. However it is also very often met in young people sustaining sedentary work (white collars or students). The cause of the pain is very often related to patella malalignment and instability with or without articular cartilage lesions in the patellofemoral joint. Articular cartilage injuries are very common in this patient group. Hielle et al. found from patients who underwent an arthroscopy that 17% of them had an articular cartilage injury located in the patella or trochlea [11]. Nomura et al. also assessed 37 patients with a first time acute patellar dislocation, finding severe articular cartilage injuries of the patella in 35 of them [19].