Figure 1. Anteroposterior radiographic view of the left foot.
Figure 2. Lateral view of left foot.
A 12-year-old girl presents to the emergency room with severe left ankle pain after twisting her ankle and falling while running earlier in the day. On physical examination of the left ankle, her skin is intact with mild swelling over the medial and lateral aspects of the ankle. Ankle range of motion is limited due to pain and swelling. Anteroposterior and lateral radiographic views of the ankle are shown in Figures 1 and 2.
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A triplane ankle fracture is a unique pattern that occurs at the distal tibial epiphysis during the period of physeal closure or around 12 to 15 years of age. Triplane refers to the pattern of fracture in the sagittal, transverse, and coronal planes. Specifically, the pattern includes a vertical fracture through the epiphysis, a horizontal fracture through the physis, and an oblique fracture through the metaphysis. The presence of a metaphyseal fracture distinguishes a triplane fracture from a Tillaux fracture.1,2
Triplane fractures most commonly occur from a twisting injury during sports. The fracture can be in multiple fragments that are difficult to visualize on plain radiographs. Like most displaced intra-articular distal tibia fractures, computed tomography scan (CT) is necessary to better visualize the fracture pattern and determine fracture displacement.3
Indications for surgery for triplane fractures include more than 2 mm of intra-articular displacement.2 Without an anatomical reduction, patients are at risk for premature physeal closure, ankle deformity, and osteoarthritis.1-3
Dagan Cloutier, MPAS, PA-C, practices in a multispecialty orthopedic group in the southern New Hampshire region and is editor in chief of the Journal of Orthopedics for Physician Assistants.
1. Schnetzler KA, Hoernschemeyer D. The pediatric triplane ankle fracture. J Am Acad Orthop Surg. 2007;15(12):738-747. doi:10.5435/00124635-200712000-00007
2. Shamrock AG, Varacallo M. Triplane ankle fracture. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; March 14, 2021. Accessed May 4, 2021.
3. Liporace FA, Yoon RS, Kubiak EN, et al. Does adding computed tomography change the diagnosis and treatment of Tillaux and triplane pediatric ankle fractures? Orthopedics. 2012;35(2):e208-212. doi:10.3928/01477447-20120123-11