Pediatric Ankle Injuries
Ankle injuries are very common, representing 25 percent of all physeal injuries in kids. Most of these injuries are related to sports incidents. They account for up to 40 percent of all injuries in child athletes. Ligamentous injuries are quite rare owing to the relative strength of the ligaments. After the age of 16, the fractures follow more of an adult pattern.
The mechanism of injury can be direct and involves ankle trauma as a result of a fall, motor vehicle accident, or a pedestrian/motor vehicle accident. Indirect injuries can occur when the body twists upon a foot that is planted on the ground.
Patients with this type of injury usually have pain and swelling of the ankle. They often cannot walk on the foot. There can be neurovascular compromise so all of the distal pulses should be looked at and the nerve function assessed. The foot and ankle need to be evaluated for the presence of open fractures. There can be injuries to the leg and knee as well so this must be evaluated.
X-rays involve frontal, side, and mortise views of the ankle. The leg may also need to be x-rayed. Stress views may show hidden fractures. CT scanning may need to be done in order to evaluate intra-articular fractures and their displacement. MRI scanning is indicated to look for soft tissue injuries.
Treatment involves closed reduction and casting with a short leg walking cast for 4-6 weeks. Percutaneous pinning is indicated in some circumstances. If there is a distal tibial fracture of the medial malleolus, closed reduction is the preferred method of treatment. Open reduction is needed with placement of a compression screw or Kirschner wiring. In Salter-Harris III or IV fractures, it is vital to have anatomic alignment. If this can’t be done using closed methods, surgery is required. Afterward, the child is placed in a short leg cast for about 6 weeks. Weekly x-rays are needed to make sure the fracture remains properly aligned.
Complications include an angular deformity if there is premature closure of the physis. Varus deformity is common as is a valgus deformity. Rotational deformities are possible and there can be a leg length discrepancy and posttraumatic arthritis if the articular surface isn’t lined up correctly.