Fractures In and Around the Knee Joint

Abstract

Fractures of the femur in children are usually situated in the diaphysis and seldom occur in the metaphysis or epiphysis. Unusually severe violence is required to fracture the femur in the vicinity of the knee joint. Road traffic accidents are the most frequent cause, and there are often concomitant injuries with severe damage to the soft tissues surrounding the fracture. Direct violence usually leads to metaphyseal fracture of the supracondylar femur without involvement of the epiphyseal plate. Indirect violence, such as hyperextension of the knee joint generates shear forces in the distal femur which cause simple separation of the epiphysis. If there is an additional bending component, separation of the epiphysis occurs with the inclusion of a metaphyseal fragment (Aitken I). During forcible abduction or adduction of the knee joint with simultaneous axial compression, the pressure of the medial or lateral tibial plateau on the corresponding femoral condyle causes the latter to break away. The resulting fracture transects the growth cartilage of the epiphyseal plate and abnormal growth frequently results. The same trauma mechanism may lead to avulsion of a collateral ligament; since the insertion of the latter is adjacent to the epiphyseal plate, an injury of this type may also be followed by abnormal growth.