Stability and Instrumentation Stresses Among Sacropelvic Fixation Techniques With Novel Porous Fusion/Fixation...

Area of Science:

• Spinal surgery
• Biomechanical engineering
• Orthopedic implants

Background:

• Sacropelvic fixation is crucial for thoracolumbar instrumentation in spinal deformity correction.
• Novel porous fusion/fixation implants (PFFI) offer potential advancements in fixation techniques.

Purpose of the Study:

• To characterize the biomechanical performance of PFFI in sacropelvic fixation.
• To compare different configurations of PFFI against traditional methods.

Main Methods:

• Finite element models of T10-pelvis constructs were created with varying PFFI placements (S2AI, PFFI-IFSAI, 2-PFFI).
• Models were subjected to pure moment loads simulating flexion-extension, lateral bending, and axial rotation.
• Outputs were compared to baseline models using pedicle screws and S2AI screws.

Main Results:

• PFFI in the S2AI trajectory showed similar L5-S1 motion to S2AI screws, with 2-PFFI configurations further reducing motion.
• Sacroiliac joint motion was reduced with PFFI-IFSAI and 2-PFFI configurations.
• PFFI decreased maximum stresses on S1 pedicle screws and S2AI implants.

Conclusions:

• Supplementing long spinal constructs with PFFI enhances L5-S1 and sacroiliac joint stability.
• PFFI reduces stress on critical fixation points, potentially lowering risks of pseudarthrosis and implant failure.