Division of Orthopaedic Surgery, Oslo University Hospital Ullevål, Oslo.
Division of Orthopaedic Surgery, Oslo University Hospital Ullevål, Oslo; Institute of Clinical Medicine, University of Oslo, Norway.
Acta Orthop. 2023 Jul 20;94:366-372. doi: 10.2340/17453674.2023.16905.
3-dimensional midfoot motion is hard to evaluate in clinical practice. We present a new computed tomography (CT)-based radiostereometric analysis (CT-RSA) technique to examine in vivo midfoot kinematics during single-leg stance and compare it with marker-based radiostereometry (RSA).
8 patients were examined with bilateral non- and full-weight-bearing CT images of the midfoot. 1st tarsometatarsal motion was analyzed using a surface-registration technique (CT-RSA). As all patients had unilateral tantalum markers in the 1st cuneiform (C1) and 1st metatarsal (M1), comparison of precision with markerbased RSA was performed. CT-RSA precision was evaluated with surface registration of both C1-M1 bone and C1-M1 tantalum markers, while RSA precision was determined with C1-M1 markers only. Additionally, to remove motion bias, we evaluated intrasegmental CT-RSA precision by comparing proximal with distal part of M1.
Under physical load, the primary movement for the 1st tarsometatarsal joint was M1 dorsiflexion (mean 1.4°), adduction (mean 1.4°), and dorsal translation (mean 1.1 mm). CT-RSA precision, using surface bone or markers, was in the range of 0.3-0.7 mm for translation and 0.6-1.6° for rotation. In comparison, RSA precision was in the range of 0.4-0.9 mm for translation and 1.0-1.7° for rotation. Finally, intrasegmental CT-RSA precision was in the range of 0.1-0.2 mm for translation and 0.4-0.5° for rotation.
CT-RSA is a valid and precise, non-invasive method to measure midfoot kinematics when compared with conventional RSA.
临床实践中很难评估 3 维中足运动。我们提出了一种新的基于计算机断层扫描（CT）的放射立体测量分析（CT-RSA）技术，用于检查单腿站立时的中足运动，并与基于标记的放射立体测量术（RSA）进行比较。
8 例患者接受双侧非负重和全负重 CT 扫描中足图像检查。第 1 跖楔关节运动采用表面配准技术（CT-RSA）进行分析。由于所有患者的第 1 楔骨（C1）和第 1 跖骨（M1）均有单侧钽标记，因此进行了基于标记的 RSA 比较精度。通过比较 C1-M1 骨和 C1-M1 钽标记的表面配准，评估了 CT-RSA 精度，而 RSA 精度仅通过 C1-M1 标记确定。此外，为了消除运动偏差，我们通过比较 M1 的近端和远端部分来评估节内 CT-RSA 精度。
在物理负荷下，第 1 跖楔关节的主要运动是 M1 背屈（平均 1.4°）、内收（平均 1.4°）和背侧平移（平均 1.1mm）。使用表面骨或标记的 CT-RSA 精度，平移范围为 0.3-0.7mm，旋转范围为 0.6-1.6°。相比之下，RSA 精度的平移范围为 0.4-0.9mm，旋转范围为 1.0-1.7°。最后，节内 CT-RSA 精度的平移范围为 0.1-0.2mm，旋转范围为 0.4-0.5°。
与传统 RSA 相比，CT-RSA 是一种有效且精确的、非侵入性的测量中足运动的方法。
