Comparative studies of computed tomography morphology of posterior pilon fracture and posterior malleolar fracture

Objective: To compare morphological differences shown by computed tomography and provide help for the diagnosis and treatment of posterior pilon fracture fragments and posterior malleolar fracture fragments. Methods: The fractures were classified into cases of posterior pilon fracture and posterior malleolar fracture, and angle (α), angle (β), FAR1) and FAR2 were measured. Results: 51.3% of posterior pilon fractures involved posterior subluxation or dislocation of talus, while 8.5% of posterior malleolar fracture involved lateral subluxation; Skew angle α of posterior pilon fractures and posterior malleolar fractures showed no statistical difference (P = 0.18), while skew angle β of posterior pilon fractures and posterior malleolar fractures showed a statistical difference: skew angle β of posterior pilon fractures is larger than for posterior malleolar fractures (P = 0.04); FAR1 was ≥25% in 48.0% of posterior pilon fracture fragments, while FAR2 was ≥25% in 55.9% of posterior pilon fracture segments. For all posterior malleolar fracture fragments, FAR1 and FAR2 were both <25%. FAR1 and FAR2 of posterior pilon fractures was statistically significantly higher than for posterior malleolar fractures (P = 0.00). Conclusion: The transverse fracture lines of posterior pilon fractures and posterior malleolar fractures are variable. Posterior pilon fractures is much vertical with respect to the ground. Posterior pilon fractures have a higher risk of ankle joint subluxation or dislocation than posterior malleolar fractures. Posterior pilon fractures have significantly larger transverse and sagittal plane area ratios than posterior malleolar fractures. Copyright © 2015 American Scientific Publishers. All rights reserved.