Any young child with what seems like an “ankle sprain” must be checked for a bone fracture (break). The skeletally immature ankle (bone growth isn’t complete yet) is more cartilage, soft tissue, and ligament than bone. The physeal (growth) plate in children is more likely to fracture before any of the soft tissues are ruptured or damaged. Obvious swelling and bruising are signs of a possible fracture, especially in children younger than 13.
One of the biggest concerns for children with ankle fractures is the risk of damage to the growth plate called physeal arrest. Surgeons evaluating children with physeal fractures of the lower leg bones (tibia and fibula) must be very careful to identify the specific type of fracture and all other areas that might also be injured (e.g., soft tissues such as cartilage, tendons, ligaments).
X-rays and CT scans will be ordered. Joint spaces, bone alignment, damage to the physeal plate, and bone gapping may be revealed. The surgeon is looking for the type of fracture present, especially if there is a fracture that involves the epiphyseal plate or “growth plate” of a bone. It is a common injury the long bones of children. Any fracture that interferes with the growth plate can cause growth to stop and local fusion of the involved bone. Therefore, these injuries can cause deformity of the joint.
Other complicating factors that can require surgery involve fractures that are displaced (two ends of the bones have separated) or fractures with many fragments of bone. The surgeon won’t necessarily be able to quickly and easily reduce or set the bone back in place. More complicated fractures require an open incision and possibly the use of wires, screws, or metal plates to hold the bones together while healing takes place.
Of course, these are all just possibilities. Until your parents come back and fill in the story for you, the details will remain a mystery! Hopefully, this brief description will help you understand the explanation you receive when it comes. And good luck to your sister!