Anatomical imaging analysis of screw configuration for femoral neck fracture / 解剖学报

[Abstract] Objective To investigate the optimal screw configuration for internal fixation of femoral neck fractures based on anatomic analysis on radiologic imaging. Methods From January to February 2017, thirty proximal femurs of 15 nonnal adults from Picture Archiving and Communication Systems (PACS) of Paople' s Hospibal of Anji were constructed by CT. 8 males and 7 females with a mean age of (43±8. 5) years (ranging from 28 to 63 years) .The medial femoral neck sections (FNS) were projected on the lateral femoral trochanteric wall. The simulated three screw configurations in the projection of FNS include: two inverted equilateral triangles symmetrized to the axis of the FNS (IET-FNS group) or the coronal axis of the proximal femur (IET-PF group) and an obtuse triangle (OT group).The distance between the screws, the distance between the centre of the FNS and the screws, and the area ratio of the triangle/FNS were calculated. Results The projection of the FNS on the lateral femoral trochanteric wall was displayed as a rotating forward ellipse. Measurements of distance between screws

Finite Element Analysis on Bone Healing Under Different Screw Configurations / 医用生物力学

Objective To explore the effects of screw configurations on bone healing, so as to provide the basis for related fracture treatment. Methods The process of bone healing under different screw configurations was studied by finite element method, and the change in the process of callus growth during healing periods was simulated by interfragmentary strain theory (IFS). The iterative process for renewing callus modulus in every finite element was conducted by the second-developed ABAQUS based on Python scripting language, thus the process of fracture healing was simulated. Results The effect from different numbers of screws on bone healing was smaller than that from different working length of bone plates. On the premise of stable fixation, given the certain working length of bone plates, the effect from different screw numbers on stress distributions in plates or screws was relatively small, while the effect from different working length on stress distributions in plates or screws was relatively large, and the stress distribution in plates was larger than that in screws at different working length. Conclusions It is necessary to take more consideration on working length of bone plates than the number of screws when they are under a stable fixed situation, and it is a wise choice to reduce the screw numbers and choose a suitable working length for bone healing process.