SLR - September 2015 - Tiffany K. Hoh

Pediatric Triplane Ankle Fractures: Impact of Radiographs and Computed Tomography on Fracture Classification and Treatment Planning

Reference: Eismann EA, Stephan ZA, Mehlman CT, Denning J, Mehlman T, Parikh SN, Tamai J, Zbojniewicz A. Pediatric Triplane Ankle Fractures: Impact of Radiographs and Computed Tomography on Fracture Classification and Treatment Planning. J Bone Joint Surg Am. 2015 Jun 17;97(12):995-1002.

Scientific Literature Review

Reviewed By: Tiffany K. Hoh, DPM
Residency Program: MedStar Washington Hospital Center

Podiatric Relevance: Pediatric triplane ankle fractures are variable, multifaceted fractures that often occur between then ages of twelve to fifteen when partial closure of the growth plates occurs. Several classification systems have been developed for this specific fracture pattern, however the reliability of these systems has not been established. This study’s purpose was to compare the reliability of the Rapariz pediatric triplane fracture classification, measurement of fracture displacement, and treatment planning between radiographs alone and radiographs with CT.

Methods: This was a retrospective review of twenty-five triplane ankle fractures of patients who had both radiographs and CT scans prior to treatment. Five raters classified the fracture pattern, measured the intra-articular displacement, and drew out the fracture lines on four outlines of the distal tibia given radiographs alone. Three surgeons drew out screw placements on an axial outline above the physis and below the physis. These raters and surgeons repeat this with additional CT scans. The Cohen kappa was used to determine the inter-rater reliability for fracture pattern and screw placement planning.

Results: There was improvement of the inter-reliability for classifying the number of fracture fragments with additional CT scans from kappa 0.20 to 0.41 as well as increase in the number of fragments identified in 76 percent of ratings. There was a 41 percent change in treatment plan with regards to number of screws or screw placement greater than 20 degrees. Screw placement occurred 21 percent above the physis and 20 percent below the physis.

Conclusions: Because of the complex orientation of the triplane fracture pattern, classifying and treating these fractures using the Rapariz classification with radiographs alone had poor reliability. Triplane ankle fracture classification, displacement, and treatment were impacted with the additional use of CT scans. CT scans improves reliability by allowing the surgeon to visualize these complex triplane fracture patterns better and plan preoperative surgical treatment. However, caution should be used for treatment and prognosis using fracture classification systems because lack of sufficient reliability still remains.

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