Knee and Ankle Injuries in Children

Abstract

The response of the skeletally immature child to musculoskeletal trauma is often quite different from the adult response to the same pattern of injury. The open growth plate is the primary factor accounting for this difference. The energy-absorbing capability of the growth plate is lower than that of bone, ligament, or tendon, which explains why the open growth plate is the preferential site for failure when a joint is injured. Because the growth plate will fail before these other structures, a true sprain of a child9s knee or ankle ligaments will be infrequent compared with the common nature of these injuries in adults. Injuries About the Knee Beware of the child with knee pain, and always consider the possibility of referred pain from the hip consequent to hip disorders of childhood or adolescence. Always fully examine the hip of a child who is complaining of knee pain. Also, examine the back to be certain the knee pain is not the result of pathology in the spine. ANATOMY The knee is a hinge joint that primarily permits flexion and extension. Small amounts of rotation are allowed but are carefully controlled by the ligamentous structures. Children usually exhibit greater ligamentous laxity than do adults. If laxity seems excessive in one knee, the opposite knee should be examined for comparison (ie, the control knee).