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

Background: The purpose of this study was to compare the reliability of triplane fracture classification, displacement measurement, and treatment planning with the use of radiographs with and without computed tomography. Methods: One pediatric radiologist, one musculoskeletal radiologist, and three fellowship-trained pediatric orthopaedic surgeons rated a spectrum of twenty-five triplane fractures with use of radiographs alone and then with computed tomography scans on two separate occasions (two to four weeks apart). Raters classified the fracture pattern with use of the Rapariz classification system, measured the maximum intra-articular displacement, and drew the fracture on four outlines of the distal part of the tibia: one lateral view, one anteroposterior view, one axial view above the tibial physis, and one axial view below the physis. Reliability was assessed with kappa values and intraclass correlation coefficients. Results: The Rapariz triplane fracture classification had poor inter-rater reliability (a kappa of 0.17) and intra-rater reliability (a kappa of 0.31) with radiographs alone but moderate inter-rater reliability (a kappa of 0.41) and intra-rater reliability (a kappa of 0.54) with the addition of computed tomography. After reviewing computed tomography, raters changed the fracture pattern in 46% of ratings, the displacement from <= 2 mm to > 2 mm in 39% of ratings, the treatment from nonoperative to operative in 27% of ratings, and either the orientation or number of screws in 41% of ratings. Conclusions: Computed tomography had a definite impact on the fracture classification, displacement, and treatment plan, supporting its use as an adjunct to radiographs for the treatment of pediatric triplane fractures.