Can MRI accurately detect pilon articular malreduction? A quantitative comparison between CT and 3T MRI bone models

Area of Science:

• Orthopedic surgery
• Medical imaging
• Biomechanical analysis

Background:

• Pilon fractures present surgical challenges, with conventional radiographs inadequately assessing reduction quality.
• Quantifying articular malreductions is crucial for optimal patient outcomes.
• Existing imaging modalities have limitations in evaluating complex fracture patterns.

Purpose of the Study:

• To develop and evaluate a method for quantifying articular malreductions in pilon fractures.
• To compare the utility of 3D computed tomography (CT) and magnetic resonance imaging (MRI) models for assessing fracture reduction.
• To investigate the accuracy of MRI in evaluating postoperative articular congruity.

Main Methods:

• Human cadaveric ankle specimens underwent simulated tibial pilon fractures (AO type B and C).
• Fractures were reduced and stabilized, followed by CT and MRI data acquisition.
• 3D CT and MRI models were reconstructed and analyzed for intra-articular steps, gaps, surface deviations, malrotations, and maltranslations.

Main Results:

• Type B fracture CT and MRI models demonstrated comparable measurements for steps, surface deviations, rotation, and translation.
• Type C fracture MRI models were compromised by metal artifacts, rendering them unsuitable for analysis.
• Type C fracture CT models showed measurable differences in surface deviation, rotation, and translation compared to contralateral models.

Conclusions:

• 3D MRI models show promise for postoperative assessment of type B pilon fracture reduction, comparable to CT.
• CT remains a viable option for evaluating type C fractures, despite limitations with MRI due to artifacts.
• Case-by-case evaluation is recommended when utilizing MRI for postoperative assessment of pilon fracture reduction.