Radzi Shairah, Dlaska Constantin Edmond, Cowin Gary, Robinson Mark, Pratap Jit, Schuetz Michael Andreas, Mishra Sanjay, Schmutz Beat
Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.
Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia;; Trauma Services, Princess Alexandra Hospital, Brisbane, Australia.
Quant Imaging Med Surg. 2016 Dec;6(6):634-647. doi: 10.21037/qims.2016.07.01.
Pilon fracture reduction is a challenging surgery. Radiographs are commonly used to assess the quality of reduction, but are limited in revealing the remaining bone incongruities. The study aimed to develop a method in quantifying articular malreductions using 3D computed tomography (CT) and magnetic resonance imaging (MRI) models.
CT and MRI data were acquired using three pairs of human cadaveric ankle specimens. Common tibial pilon fractures were simulated by performing osteotomies to the ankle specimens. Five of the created fractures [three AO type-B (43-B1), and two AO type-C (43-C1) fractures] were then reduced and stabilised using titanium implants, then rescanned. All datasets were reconstructed into CT and MRI models, and were analysed in regards to intra-articular steps and gaps, surface deviations, malrotations and maltranslations of the bone fragments.
Initial results reveal that type B fracture CT and MRI models differed by ~0.2 (step), ~0.18 (surface deviations), ~0.56° (rotation) and ~0.4 mm (translation). Type C fracture MRI models showed metal artefacts extending to the articular surface, thus unsuitable for analysis. Type C fracture CT models differed from their CT and MRI contralateral models by ~0.15 (surface deviation), ~1.63° (rotation) and ~0.4 mm (translation).
Type B fracture MRI models were comparable to CT and may potentially be used for the postoperative assessment of articular reduction on a case-to-case basis.
Pilon骨折复位是一项具有挑战性的手术。X线片常用于评估复位质量，但在显示剩余骨不连续方面存在局限性。本研究旨在开发一种使用三维计算机断层扫描（CT）和磁共振成像（MRI）模型量化关节复位不良的方法。
使用三对人体尸体踝关节标本获取CT和MRI数据。通过对踝关节标本进行截骨术模拟常见的胫骨Pilon骨折。然后对其中五处骨折（三处AO B型骨折（43-B1）和两处AO C型骨折（43-C1））进行复位并用钛植入物固定，随后再次扫描。所有数据集均重建为CT和MRI模型，并就关节内台阶和间隙、表面偏差、骨碎片的旋转不良和平移不良进行分析。
初步结果显示，B型骨折的CT和MRI模型在台阶方面相差约0.2、表面偏差约0.18、旋转约0.56°、平移约0.4mm。C型骨折的MRI模型显示金属伪影延伸至关节表面，因此不适合分析。C型骨折的CT模型与其对侧的CT和MRI模型在表面偏差方面相差约0.15、旋转约1.63°、平移约0.4mm。
B型骨折的MRI模型与CT相当，可能可逐例用于关节复位的术后评估。
