A child’s bones differ from those of an adult. Instead of fracturing completely, they often bend like a stick (incomplete or greenstick fractures), or there may only be asmall swelling of the cortex (wrinkle fractures). Fractures in children always unite if you treat them properly; they need immobilizing for a shorter time, and you can almost always manage them by closed methods. Skin traction is much more satisfactory in children than it is in adults, and, because a child’s joints do not become stiff permanently, he seldom needs physiotherapy.
Although some severe malpositions slowly disappear as a child grows, other apparently mild ones become steadily worse. So you must know which positions you can accept, and which you cannot. Here are some general principles.
(1) Try to get the fragments into line. They need not necessarily be end to end.
(2) Try to stop them rotating, because growth will not correct a rotation deformity.
(3) Be cautious about how much angulation you accept. This depends on: (a) The age of the child, and particularly on whether his epiphyses have united or not. In Caucasians they typically unite at 14 in a girl and 16 in a boy, but in an African they may remain open almost to the age of 20. (b) The distance of the fracture from the end of a long bone. The younger the child, and the nearer his fracture to the end of his bone, the greater the angulation you can accept. Uncorrected angulated fractures near the middle of a long bone cause severe deformity, especially in the forearm, and also in the femur and tibia. But angulation near the end of a bone in the plane of a hinge joint, such as the elbow, fingers, or knee, causes very little disability. Angulation in other directions is likely to be permanent.
(4) Overlap and moderate shortening are unimportant. In fractures of the femur and humerus in younger children, they are even desirable, because these bones readily regrow to their normal length. So you can leave a fractured long bone to unite with its fragments side to side up to the age of 10 in girls, and 12 in boys. The fragments unite rapidly, and the bone soon moulds.