Department of Orthopedics, Balgrist University Hospital, University of Zurich, Forchstrasse 340, 8008, Zurich, Switzerland.
Research in Orthopedic Computer Science (ROCS), Balgrist University Hospital, University of Zurich, Balgrist CAMPUS, Zurich, Switzerland.
Sci Rep. 2024 Jun 4;14(1):12839. doi: 10.1038/s41598-024-62410-7.
Corrective osteotomy allows to improve joint loading, pain and function. In complex deformities, the biggest challenge is to define the optimal surgical solution, while considering anatomical, technical and biomechanical factors. While the single-cut osteotomy (SCOT) and focal dome osteotomy (FDO) are well-established treatment options, their mathematical relationship remain largely unclear. The aim of the study was (1) to describe the close mathematical relationship between the SCOT and FDO and (2) to analyze and introduce a novel technique-the stepped FDO-as a modification of the classic FDO. The mathematical background and relationship of SCOT and FDO are described for the example of a femoral deformity correction and visualized using a 3D surface model taking into account the benefits for the clinical application. The novel modifications of the stepped FDO are introduced and its technical and clinical feasibility demonstrated. Both, SCOT and FDO, rely on the same deformity axis that defines the rotation axis k for a 3D deformity correction. To achieve the desired correction using a SCOT, the resulting cutting plane is perpendicular to k, while using a FDO will result in a cylindrical cut with a central axis parallel to k. The SCOT and FDO demonstrate a strong mathematical relation, as both methods rely on the same deformity axis, however, resulting in different cutting planes. These characteristics enable a complementary use when defining the optimal type of osteotomy. This understanding enables a more versatile planning approach when considering factors as the surgical approach, biomechanical characteristics of fixation or soft tissue conditions. The newly introduced stepped FDO facilitates an exact reduction of the bone fragments and potentially expands the clinical applicability of the FDO.
矫正性截骨术可以改善关节的负重、疼痛和功能。在复杂的畸形中，最大的挑战是定义最佳的手术解决方案，同时考虑到解剖学、技术和生物力学因素。虽然单一切割截骨术 (SCOT) 和焦点穹顶截骨术 (FDO) 是成熟的治疗选择，但它们的数学关系在很大程度上仍不清楚。本研究的目的是：(1) 描述 SCOT 和 FDO 之间的紧密数学关系；(2) 分析并介绍一种新的技术——阶梯 FDO，作为经典 FDO 的一种改良。通过考虑临床应用的优势，采用考虑到股骨畸形矫正的 3D 表面模型，描述了 SCOT 和 FDO 的数学背景和关系，并对其进行了可视化。介绍了阶梯 FDO 的新颖改良，并证明了其技术和临床可行性。SCOT 和 FDO 都依赖于同一畸形轴，该轴定义了用于 3D 畸形矫正的旋转轴 k。为了使用 SCOT 实现所需的矫正，所得切割平面垂直于 k，而使用 FDO 将导致与 k 平行的中央轴的圆柱切割。SCOT 和 FDO 表现出很强的数学关系，因为这两种方法都依赖于相同的畸形轴，但产生的切割平面不同。这些特征使在定义最佳的截骨类型时能够互补使用。这种理解为考虑手术入路、固定的生物力学特性或软组织状况等因素时提供了更灵活的规划方法。新引入的阶梯 FDO 便于精确还原骨块，并可能扩大 FDO 的临床适用性。
