Triplane and Tillaux fractures: is a 2 mm residual gap acceptable?

Children's ankle fractures are the second most common growth plate fractures in humans and one of the top 10 reasons for pediatric orthopaedic hospital admissions. Because triplane and Tillaux fractures occur during the period of distal tibial physeal closure, they are considered transitional injuries. The distal tibial physis closes in a unique, asymmetric pattern (middle, then medial, and finally lateral), and it is the portion of the physis that is open at the time of injury that is vulnerable to fracture in this age group. Triplane and Tillaux fractures occur after supination external rotation and compression stress with unpredictable multiplanar fracture patterns. The fracture may appear different on different x-ray projections, making computed tomography mandatory to determine the number of fragments. Because most of these fractures are intra-articular, anatomic or near-anatomic reduction of the joint surface is recommended to minimize future posttraumatic ankle arthritis. Because these fractures occur at the end of growth, they rarely result in growth arrest.