[Dislocation and subluxation of the patella]

Subluxations or dislocations are present in adolescents and young adults, they are caused by malalignments of the leg (rotation, axis, extensor mechanism). In subluxation, functional therapy is the method of choice, dislocations with haemarthrosis are an indication for arthroscopy. After the first dislocation without chondral lesion, consequent functional treatment has a recurrence rate of only 5 per cent. Recurrent dislocations need a reconstruction of the extensor mechanism to prevent chondral damage.