This patients ankle fracture is a translational injury, which typically occurs during the 18 months in which the distal tibial physis undergoes asymmetric closure.1 Triplane fractures often present in children aged 12 to 15 years, with a slightly higher incidence in males than females. There are multiple variations of the triplane fracture, and they represent 5% to 10% of pediatric intra-articular ankle injuries.1 Closure of the distal tibial physis occurs in an asymmetric pattern, starting centrally, then anteromedially, and then posteromedially; the lateral portion of the physeal plate is the final area of closure. Figure 1 shows a 3-part triplane ankle fracture, best described as a Salter-Harris type III fracture on the anteroposterior radiograph and a Salter-Harris type II fracture on the lateral radiograph (with a metaphyseal spike posteriorly). Axial CT images clearly demonstrate 3 fracture fragments. A Thurston-Holland fracture is not a type of ankle fracture but rather a description of a coronal plane fracture fragment. A Salter-Harris type V injury is a crush injury to the growth plate, often diagnosed when a leg length discrepancy or growth disturbance is found several years after the injury is sustained.2 Tillaux fractures involve the anterolateral aspect of the distal tibia and are found in children slightly older than those who experience triplane fractures. A Tillaux fracture is indicative of an avulsion of the anterior inferior tibiofibular ligament during the time of asymmetric closure of the distal tibial physis.2 Maisonneuve fractures are injuries to the syndesmosis, typically associated with a high fibula fracture and asymmetry of the medial ankle mortise.
- Triplane fracture.
1. Schnetzler KA, Hoernschemeyer D. The pediatric triplane ankle fracture. J Am Acad Orthop Surg 2007;15:738–47.
2. Kay RM, Matthys GA. Pediatric ankle fractures: evaluation and treatment. J Am Acad Orthop Surg 2001;9:268–78.
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Seminars in Medical Practice
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