Related Experiment Video
Updated: Oct 16, 2026
Modified Posterior Vertebral Column Resection for Patients with Thoracolumbar Kyphotic Deformity
Published on: September 16, 2022
Biomechanical comparison of multirod constructs for severe thoracolumbar Pott's deformity following posterior
Junlong Zhong1,2, Wen Tan1, Shengbiao Ma1
1Orthopaedic Hospital, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, China.
Study Design:
Finite element study.
Purpose:
This study aimed to compare the biomechanical performance of three multirod constructs used in posterior vertebral column resection (PVCR) for severe thoracolumbar Pott's deformity.
Overview Of Literature:
The optimal configuration of the multirod constructs for spinal deformity correction remains controversial.
Methods:
A patient-specific three-dimensional spinal model was constructed, and PVCR was simulated using modeling software. Three fixation configurations were evaluated: (A) conventional dual rods with accessory rods bridging the osteotomy site, (B) short-segment fixation adjacent to the osteotomy with long proximal and distal rods, and (C) long rods engaged with staggered screws. A 10-N·m moment was applied to simulate flexion, extension, lateral bending, and axial rotation. Implant stress and vertebral displacement were recorded for each model.
Results:
Under flexion, the maximum implant stresses of Models A, B, and C were 92, 99, and 131.1 MPa, respectively, occurring at the most cranial screws. Under extension, the corresponding values were 95, 101, and 131.6 MPa, respectively, occurring at the most cranial screws. Under lateral bending, the maximum stresses were 125.9, 118.5, and 155 MPa, respectively, at the cranial rod segments. Under axial rotation, the corresponding values were 213.7, 199, and 214 MPa, respectively, at the most cranial screws. The respective maximum vertebral displacements for Models A, B, and C were 2.4, 2.5, and 2.8 mm in flexion; 2.7, 2.8, and 3.1 mm in extension; 1.3, 1.4, and 2.3 mm in lateral bending; and 1.6, 2.4, and 2.1 mm in rotation.
Conclusions:
Implant stress in PVCR was predominantly concentrated at the most cranial screws and cranial rod segments. In this finite element analysis, Models A and B demonstrated lower implant stress and construct displacement than Model C under most loading conditions.