Stabilization of Traumatic Iliosacral Instability Using Innovative Implants: A Biomechanical Comparison

Area of Science:

• Orthopedic surgery
• Biomechanics
• Geriatric orthopedics

Background:

• Pelvic ring fractures are increasing in the orthogeriatric population due to demographic shifts.
• Fragility fractures present unique implant fixation challenges.
• This study addresses the need for improved stabilization methods for iliosacral joint injuries.

Purpose of the Study:

• To biomechanically compare the stability of two innovative iliosacral implants: the SI-Plate and the TriFix system.
• To evaluate implant fixation and primary stability in osteoporotic bone models simulating pelvic fractures.

Main Methods:

• Utilized osteoporotic artificial bone models with simulated Denis zone 1 pelvic fractures.
• Instrumented models with an SI-Plate (iliac screw with preassembled plate) and a TriFix system (triangular fixation).
• Performed biomechanical testing using cyclic axial and torsional loading to failure on a servo-hydraulic machine.

Main Results:

• Both SI-Plate and TriFix demonstrated comparable stiffness.
• TriFix showed significantly lower fracture gap angle and screw tip cutout.
• TriFix exhibited a significantly higher number of cycles to failure, indicating greater durability.

Conclusions:

• The triangular stabilization system (TriFix) enhances implant anchorage and primary stability in iliosacral instability.
• TriFix offers a biomechanically superior option for treating pelvic ring fractures in osteoporotic bone.
• Innovative implant designs are crucial for addressing challenges in orthogeriatric fracture care.