Arts et Metiers ParisTech, LBM, 151 bd de l'hopital, 75013 Paris, France.
Med Eng Phys. 2013 Dec;35(12):1703-12. doi: 10.1016/j.medengphy.2013.07.002. Epub 2013 Aug 12.
Three-dimensional (3D) reconstruction of lower limbs is essential for surgical planning and clinical outcome evaluation. 3D reconstruction from biplanar calibrated radiographs may be an alternative to irradiation issues of CT-scan. A previous study proposed a two-step reconstruction method based on parametric models and statistical inferences leading to a fast Initial Solution (IS) followed by manual adjustments. This study aims to improve the IS using a new 3D database, a novel parametric model of the tibia and a different regression approach. The IS was evaluated in terms of shape accuracy on 9 lower limbs and reproducibility of clinical measurements on 22 lower limbs. Reconstruction time was also evaluated. Comparison to the previous method showed an improvement of the IS in terms of shape accuracy (1.3 vs. 1.6 and 2 mm respectively for both femur and tibia) and reproducibility of clinical measurements (i.e. 3.1° vs. 8.3° for neck-shaft-angle; 4.2° and 5° vs. 5° and 6° for tibial and femoral torsion respectively). The proposed approach constitutes a considerable step towards an automatic 3D reconstruction of lower limb.
下肢的三维（3D）重建对于手术规划和临床结果评估至关重要。双平面校准射线照相的 3D 重建可能是 CT 扫描辐射问题的替代方法。先前的研究提出了一种基于参数模型和统计推断的两步重建方法，可快速获得初始解（IS），然后进行手动调整。本研究旨在使用新的 3D 数据库、胫骨的新参数模型和不同的回归方法来改进 IS。在 9 条下肢上评估了 IS 的形状准确性，并在 22 条下肢上评估了临床测量的可重复性。还评估了重建时间。与之前的方法相比，IS 的形状准确性有所提高（股骨和胫骨分别为 1.3 毫米和 1.6 毫米），临床测量的可重复性也有所提高（即颈干角为 3.1°，而 8.3°；胫骨和股骨扭转角分别为 4.2°和 5°，而 5°和 6°）。所提出的方法是实现下肢自动 3D 重建的重要一步。
