Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, Kelvin Grove, QLD, 4059, Australia.
Jamieson Trauma Institute, Royal Brisbane and Women's Hospital, Metro North Hospital and Health Service, Herston, QLD, 4029, Australia.
Arch Orthop Trauma Surg. 2022 Jul;142(7):1531-1538. doi: 10.1007/s00402-021-03851-x. Epub 2021 Mar 11.
Antegrade nailing of proximal femur fractures is a widely accepted treatment that relies on lateral radiographs to assess distal nail positioning. However, the distal femur is trapezoidal in cross section, consequently standard lateral radiographs may be insufficient. This study aimed to utilise 3D modelling to virtually assess the accuracy of lateral radiographs in defining the position of a femoral nail in the distal femur, specifically considering distal cortical encroachment.
Three-dimensional models of a commonly used nail, were positioned in 3D models of 63 femora, generated from CT scans. Lateral projections, representative of lateral radiographs, were generated and measurements of the closest point distance between the distal nail and anterior inner cortex were recorded. Axial slices through the model at the same distal position were produced for any nails located in the canal's anterior 1/5th and used to quantify the shortest nail to anterior cortex distance.
A significant (p = 0.000) difference exists between the positions of the nail in the lateral projection (- 1.7 ± 1.24 mm) compared with axial position (- 0.23 ± 1.41 mm) with reference to the inner cortical surface. In the lateral projection, 30 nails were located in the canal's anterior 1/5th, of these, 14 nails were identified in the axial position as perforating the inner cortex, with four also perforating the outer cortex surface.
Femoral nails are often anteriorly located in the distal femur and reviewed using lateral radiographs. However, this research demonstrates that owing to the geometry of the distal femur, a lateral radiograph may be inadequate for determining the true position of a femoral nail within the distal femur. Accurately assessing the position of femoral nails may help to address and prevent thigh pain, and iatrogenic fracture or perforation which have been associated with anterior positioning.
顺行股骨近端骨折内固定是一种广泛接受的治疗方法，它依赖于侧位 X 线片来评估远端钉的位置。然而，股骨远端在横截面上呈梯形，因此标准的侧位 X 线片可能不够充分。本研究旨在利用 3D 建模来虚拟评估侧位 X 线片在确定股骨远端内钉位置方面的准确性，特别是考虑到远端皮质侵犯。
将一种常用的钉的 3D 模型放置在 63 个股骨的 3D 模型中，这些模型是从 CT 扫描中生成的。生成了代表侧位 X 线片的侧位投影，并记录了远端钉与前内皮质之间最近点距离的测量值。对于位于管腔前 1/5 处的任何钉，在相同的远端位置生成了穿过模型的轴向切片，并用于量化最短钉到前皮质的距离。
与轴向位置（-0.23±1.41mm）相比，钉在侧位投影中的位置（-1.7±1.24mm）存在显著差异（p=0.000），这与内皮质表面有关。在侧位投影中，30 枚钉位于管腔的前 1/5 处，其中 14 枚钉在轴向位置被确定为穿透内皮质，其中 4 枚也穿透了外皮质表面。
股骨近端骨折内固定是一种广泛接受的治疗方法，它依赖于侧位 X 线片来评估远端钉的位置。然而，这项研究表明，由于股骨远端的几何形状，侧位 X 线片可能不足以确定股骨远端内钉的真实位置。准确评估股骨钉的位置有助于解决和预防与前位相关的大腿疼痛、医源性骨折或穿透。
