Fixation of children’s fractures have become more widely practiced than in previous decades. This is due in part to the increasing costs of hospitalization. The principles of internal fixation include the following:
- Supplement with cast Internal fixation is often supplemented with a cast, so minimal fixation is all that is required.
- Minimal fixation is adequate because bone healing is rapid and joint motion is regained quickly following injury.
- Avoid transephyseal fixation except for small K wires.
- Flexible fixation is usually adequate for children.
- Removal of fixation devices is often optional.
- Tailor fixation Be creative. Keep in mind the age of the child, the character of the fracture, the family situation, and the physician’s skills.
Good Choices for Fixation of children’s fractures
Cast immobilization still remains the first choice for managing childhood fractures. Cast immobilization can be used alone or in combination with minimal internal fixation.
Flexible intramedullary fixation IM rod fixation is ideal for long-bone fractures in children. Flexible rods can be easily inserted and removed. Reaming is unnecessary, reducing the risk of physeal injury. Prebending the rods adds dynamic control for reduction. Single-rod fixation can be supplemented by a cast to control rotation. These devices are simpler and less expensive than rigid rods or plates. Flexible rods are especially valuable in pathologic fracture management and should be left to reduce the risk of refracture. These flexible rods are load sharing rather than load shielding. This maintains normal bone flexibility, making them more physiologic than plates or rigid rods.
Cross pin fixation is commonly used in fixation of humeral supracondylar and other metaphyseal fractures. Sometimes pin fixation is supplemented with a cast. Smooth pin ends are bent to prevent migration and usually left long outside the skin, making them easily removable. Use small, smooth pins when placing across the growth plate.
Bioabsorbable fixation by polyglycolic acid (PGA) or polylactide devices is ideal for children. Such devices are small, provide adequate fixation when supplemented by a cast, do not interfere with healing, and do not require removal. They may replace metal K wires and screws in the future.
Single screw fixation is often useful to secure the metaphyseal fragment to the metaphysis or to fix a fracture through the epiphysis.
Problems with Fixation
Plates and nail plates These may be useful for stabilizing diaphyseal fractures in children with polytrauma. Plate application and removal requires the most extensive exposure and often leaves ugly residual surgical scars. Avoid crossing the growth plate. Stress risers at the end screw increase the risk of fracture.
External pin fixation Fixation is ideal for long-bone fractures complicated by severe soft tissue injuries. This fixation allows soft tissue wound care. External pin fixation carries significant risks. These include pin tract problems and fracture unions. Refractures are common following removal of the fixation after femoral shaft fractures in children. Scars for external pins are multiple, often causing dimpling, and are difficult to revise. Sometimes refracture may be prevented by applying a cast and encouraging full weight-bearing activity after fixation removal. Once the union is solid, the cast is removed.
Rigid IM fixation Reamed rodding in long bones exposes the child to the risk of physeal damage and avascular necrosis. Reamers placed through the greater trochanter or upper femur may damage appositional or enchondral bone growth and vascularity to the femoral head, causing avascular necrosis. Reserve reaming and rigid rods for fixing fractures after physeal closure.