Related Experiment Video
Updated: Jul 15, 2026
Minimally Invasive Treatment for Thoracolumbar Burst Fracture Using Sagittal Alignment Screws and A Trauma Reduction Device
Published on: November 8, 2024
Finite element biomechanical evaluation of a novel double-door screw-plate system for posterior cervical laminoplasty
Zhihao Kang1, Kaibin Wang1, Haipeng Si1,2
1Department of Orthopedics, Cheeloo College of Medicine, Qilu Hospital of Shandong University, Shandong University, Jinan, 250012, Shandong, China.
Background:
To address the surgical challenges and postoperative implant displacement associated with conventional internal fixation techniques in posterior cervical double-door laminoplasty, we developed the double-door screw-plate system (DDSPS).
Purpose:
This study aimed to evaluate the biomechanical effects of DDSPS using finite element (FE) analysis.
Methods:
An intact adult cervical spine FE model and three postoperative fixation models representing the DDSPS, the LA lamina staple, and the hydroxyapatite (HA) spacer construct were developed. Under a 75 N follower load and a 2.0 N·m moment applied in six loading directions, ROM, mean von Mises stress, implant-bone interface micromotion, and DDSPS stress distribution were evaluated.
Results:
Across the six loading directions, all three postoperative models showed a similar overall kinematic pattern, with the greatest increase in ROM occurring during flexion and only limited changes in the remaining directions. The DDSPS and LA lamina staple models demonstrated markedly lower implant-bone interface micromotion than the HA spacer model (DDSPS CSLIP1/2: 0.0008/0.0021 mm; LA lamina staple: 0.0020/0.0019 mm; HA spacer: 0.2506/0.1560 mm). In the DDSPS model, implant stress was mainly concentrated around the connecting axis, the plate surrounding the axial-side screw holes, and the axial-side fixation screws, with maximum stresses of 48.70 MPa in the plate and 67.09 MPa in the screw.
Conclusion:
Within the present finite element framework, the double-door screw-plate system (DDSPS) demonstrated a more favorable initial biomechanical profile, including lower interface micromotion and greater construct stability than the reference constructs.
