The clinical manifestations and pathomechanics of contracture of the extensor mechanism of the knee

Abstract

Experience with 38 Asian children and adolescents who suffered from either stiffness of the knee, genu recurvatum, habitual dislocation of the patella or congenital lateral dislocation of the patella showed that all those disorders were manifestations of contracture of the extensor mechanism, which fell into 2 groups according to the components involved. In Group I the main components affected were in the midline of the limb, namely rectus femoris and vastus intermedius; these patients suffered from varying degrees of stiffness of the knee, or worse, with genu recurvatum. In Group II the main components involved were lateral to the midline of the limb, namely vastus lateralis and the ilio tibial band; these patients suffered from habitual dislocation of the patella, or worse, congenital lateral dislocation of the patella. In both groups untreated patients developed secondary adaptive changes such as subluxation of the tibia or marked genu valgum which made operative procedures more formidable and less effective. Release of the contracture should therefore be performed as early as possible.