[Imbalance of the patella in the adolescent. Physio-pathological approach and therapeutic orientation (author's transl)].

The incorrect position of the anterior tibial tuberosity responsible for the pushing into jagged shape of the extensor apparatus of the knee has various causes. Among these, "knock-kneed"walking may induce some children to compensate by a hyper rotation of the legs in order to reestablish a normal walking position. Other origins may also be pointed out : --an outward twist of the leg bones --hyper rotation in outward turning sometimes as a result of accident but more often hereditary. The closing of angle Q of the extensor system modifies the pressure vectors on the femur patellar connection leading eventually to disturbances in the growth of its outer side and to a distension of the inner stabilizing elements leading to partial dislocation of the patella. This physiopathological conception should lead to a selective therapeutic orientation based on a clinical examination. In this field much can be said for dynamic interventions (lowering of the vastus medialis transferring of the pes cornivus muscles, etc...) aimed at correcting the imbalance.