Centre for Orthopaedic and Trauma Research, Adelaide Medical School, The University of Adelaide, SA, Australia; Medical Devices Research Institute, College of Science and Engineering, Flinders University, Adelaide, SA, Australia.
Centre for Orthopaedic and Trauma Research, Adelaide Medical School, The University of Adelaide, SA, Australia; Department of Orthopaedics and Trauma, Royal Adelaide Hospital, Adelaide, SA, Australia.
J Biomech. 2022 Nov;144:111275. doi: 10.1016/j.jbiomech.2022.111275. Epub 2022 Aug 27.
Postoperative weight bearing has the potential to generate fragmental motion of surgically repaired tibial plateau fractures (TPFs), which may contribute to loss of fracture reduction. The effect of loading on the internal distribution of fragmentary displacements is currently unknown. The aim of this study was to determine the internal displacements of surgically repaired split TPFs due to a three-bodyweight load, using large-volume micro-CT imaging and image correlation. Fractures were generated and surgically repaired for two cadaveric specimens. Load was applied to the specimens inside a large-volume micro-CT system and scanned at 0.046 mm isotropic voxel size. Pre- and post-loading images were paired, co-registered, and internal fragmentary displacements quantified. Internal fragmental displacements of the cadaveric bones were compared to in vivo displacements measured in the lateral split fragments of TPFs in a clinical cohort of patients who had similar surgical repair and were prescribed pain tolerated postoperative weight bearing. The split fragments of cadaveric specimens displaced, on average, less than 0.3 mm, consistent with in vivo measurements. Specimen one rotated around the mediolateral axis, while specimen two displaced consistently caudally. Specimen two also had varying displacements along the mediolateral axis where, at the fracture site, the fragment displaced caudally and laterally, while the most lateral edge of the tibial plateau displaced caudally and medially. The methods applied in this study can be used to measure internal fragmental motion within TPFs.
术后负重可能会导致胫骨平台骨折（TPF）修复后的骨折块产生碎块运动，从而导致骨折复位丢失。目前尚不清楚负重对骨折块内部移位的影响。本研究旨在使用大容量 micro-CT 成像和图像相关技术，确定三体重负荷作用下手术修复的分裂 TPF 的内部移位。为两个尸体标本生成并手术修复骨折。在大容量 micro-CT 系统内对标本施加负荷，并以 0.046mm 各向同性体素大小进行扫描。对加载前后的图像进行配对、配准，并定量内部骨折块的移位。将尸体骨骼的内部骨折块移位与临床队列中接受类似手术修复且被规定耐受疼痛的术后负重的 TPF 侧部分离骨折块的体内测量值进行比较。尸体标本的分离骨折块平均移位小于 0.3mm，与体内测量值一致。标本一绕内外轴旋转，而标本二则一致向后移位。标本二还沿内外轴有不同的移位，在骨折部位，骨折块向后和向外移位，而胫骨平台的最外侧边缘向后和向内移位。本研究中应用的方法可用于测量 TPF 内的骨折块内部运动。
