Application of three-dimensional reconstruction to improve the preoperative measurement accuracy and applicability of femoral neck torsion angle

Abstract

Conventional methods have limitations in measuring femoral neck torsion angle (FNTA) of patients with femoral deformities. A new method of three-dimensional (3D) reconstruction technology based on computer tomography (CT) was proposed to enhance measurement accuracy and applicability in this study.Bilateral FNTA of 50 developmental dysplasia of the hip (DDH) patients (DDH group) and 81 volunteers (normal group) were measured by Mimics software based on CT data with the marker lines determined by centerline and curvature. Each FNTA was measured by observer A and observer B for twice separately. 50 DDH patients were classified into 3 groups (group I, II, III) according to Hartofilakidis classification. The statistical analysis of the differences was made among the measurements of the FNTA.The FNTA values were 27.56° ± 12.48° in DDH group and 21.22° ± 8.14° in normal group with significant difference (t = 4.516, P < .001). The FNTA values were 24.53° ± 2.40° in group I, 29.78° ± 1.83° in group II and 39.08° ± 3.13° in group III, with significant difference (F = 7.568, P = .001).The accuracy, reliability and applicable scope of FNTA measurement can be improved by 3D reconstruction in clinical practice. The applicable scope of this method included normal people and patients with femoral deformities. The FNTA of DDH patients is significantly larger than normal volunteers with a positive correlation between the severity of classification. This study will also provide references for preoperative design of Chinese population.

Analysis of the Style Characteristics of National Dance Based on 3D Reconstruction

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Effect of 3D Printing Technology in Proximal Femoral Osteotomy in Children with Developmental Dysplasia of the Hip

“…Previous surgeons often evaluate the degree of proximal femoral deformity according to preoperative Xray and CT measurement results and perform proximal femoral osteotomy according to personal experience during the operation. However, there are huge errors in preoperative measurement and intraoperative operation, so it is necessary to find a more accurate method [3]. The application of 3D printing technology in the orthopedics provides the possibility for individualized and precise treatment of patients and can be used for preoperative measurement and surgical planning of patients with developmental hip dysplasia, thus effectively reducing the errors caused by surgeon's personal experience.…”