Tibial fractures account for about 8% of children’s fractures. Because the tibia has little soft tissue cover and the leg is exposed to view with normal clothing, malunion is more obvious than for most long-bone fractures. Overgrowth following fracture is less for the tibia than for the femur.
Toddler fractures occur in children 1–4 years old from minimal trauma. A faint fracture line extends obliquely across the distal metaphysis to terminate medially. Sometimes the fracture line cannot be seen on radiographs. The diagnosis of Toddlers’ Fracture can be established by imaging with a bone scan. Midshaft fractures should raise suspicion of child abuse. Manage by immobilization in a walking cast for 3 weeks.
Closed Tibial Shaft Fractures
Isolated tibial fractures in children are most common in the distal one-third. Manage by reduction and long-leg cast with the knee flexed about 30°. Make certain rotation is correct. Because of the intact fibula, a varus drift is common. Follow with weekly radiographs for 3 weeks, and wedge the cast to correct deformities exceeding about 5°.
Both-bone fractures are often easier to manage than fracutres of the tibia alone. Avoid excessive shortening. Be aware that varus angulation corrects better than valgus deformity. Wedge the cast to correct deformities exceeding 5°–10°. Side-to-side apposition is acceptable for children. Rotational deformities correct poorly.
Operative fixation of tibial fractures in children may be necessary in the adolescent if length or alignment cannot be satisfactorily managed by cast immobilization. Flexible intramedullary fixation is a good cosmetic choice, as the scars are minimal and fixation adequate. In contrast, the scars from external pin fixation or plating are less acceptable.
Polytrauma often involves the tibia. Operative fixation may be necessary; the urgency mandates the mode of fixation. Especially in the older child or adolescent, the “floating knee” may require internal fixation.
Dysplastic tibia is a rare cause of fracture. Dysplastic features include cortical tapering, sclerosis, and medullary cysts. This may represent a mild form of pseudarthrosis tibiae and can be seen in the child with neurofibromatosis. Manage with flexible intramedullary rod fixation that is not removed.
Pathologic fractures are most common through nonossifying fibromas. These lesions usually occur in the distal aspect of the tibia and have a characteristic appearance. Most fractures occur in very large lesions or secondary to a significant injury. Manage by cast immobilization until union has occurred. Because the natural history is of spontaneous resolution, curettage and bone grafting are seldom necessary.
Open Tibial Fractures
Open fractures of the tibia in child may be associated with severe trauma and have a significant mortality and amputation rate. Most fractures are less severe and are managed like other open fractures.
Severity Severe open fractures are likely to be associated with other very serious injuries and can cause significant mortality and limb loss. Because of the greater potential for healing, attempt limb salvaging whenever a possibility of success exists.
Age is a significant factor in prognosis and influences management. Children can be managed less aggressively than adolescents. Complications in adolescents are similar to those seen in adults. Manage children over the age of 12 years as adults.
Manage with intravenous antibiotics, repeated debridement, and appropriate fixation. In young children, a windowed cast may be adequate. Apply external pin fixation for older children with soft tissue injury. Intramedullary fixation is an alternative in the adolescent.
Stress fractures are not rare in children. About half occur with sports. They are becoming more common in girls. The proximal tibia and distal fibula are common sites. Girls show greater variation in location than boys. Suspect when pain and localized tenderness are found in the very active child. Initial radiographs may be negative. Bone scans show focal uptake. MRI studies are seldom indicated but show an inflammatory reaction. Manage by immobilization or limitation of activity. Monitor healing by a loss in tenderness and pain. Consider healed when asymptomatic and when the callus is mature. Displacement or nonunion occurs rarely.
Proximal Tibial Metaphyseal Fracture
Undisplaced fractures of the metaphyseal in the young child are often complicated by the development of a valgus deformity. The cause of the progressive deformity is most likely due to relative overgrowth of the tibia. This asymmetrical growth is sometimes demonstrated by obliquity of the Harris line or growth arrest line.
Manage with this complication in mind. Advise the family that a knee deformity may develop in the months after the injury even if the fracture is anatomically reduced. Immobilize the extremity in a long-leg cast flexed at about 20°. Apply varus stress during cast application. Remove the cast at 6 weeks. Follow for 6–12 months. If the deformity occurs, resist the temptation to correct by osteotomy because the deformity will likely recur. Near the end of growth, if the deformity has not resolved, correct with a hemistapling of the proximal medial tibial physis.