Biomechanical Comparison of Three Different Fixation Methods for Unstable Basicervical Intertrochanteric Fractures...

Area of Science:

• Orthopedic Surgery
• Biomechanical Engineering
• Trauma Research

Background:

• Unstable basicervical intertrochanteric fractures pose challenges in achieving stable fixation.
• Current fixation methods may lead to rotational instability and fragment migration.
• Biomechanical evaluation is crucial for optimizing fracture treatment strategies.

Purpose of the Study:

• To compare the fixation stability and mechanical properties of different cephalomedullary nail configurations.
• To evaluate the efficacy of a novel nail with an anti-rotation screw in unstable basicervical intertrochanteric fractures.
• To assess the impact of anti-rotation screw length on biomechanical outcomes.

Main Methods:

• Thirty-six synthetic femur models with unstable basicervical intertrochanteric fractures were used.
• Specimens were treated with a cephalomedullary nail and fixation using a single lag screw, or a lag screw with a 75 mm or 95 mm anti-rotation screw.
• Cyclic loading, stereophotogrammetry for rotation analysis, and radiographic measurement of screw-tip displacement were performed.
• Failure load was determined by applying a vertical load until structural failure.

Main Results:

• The group with the 95 mm anti-rotation screw showed significantly less rotational change in the sagittal plane (p=0.038).
• Axial migration was significantly lowest in the group with the 95 mm anti-rotation screw (p=0.040).
• No significant differences were found in varus/retroversion collapse, cranial migration, or failure load among groups. No significant differences were observed between the 75 mm and 95 mm anti-rotation screw groups.

Conclusions:

• A cephalomedullary nail with a long inferior anti-rotation screw enhances fixation stability for unstable basicervical intertrochanteric fractures.
• This novel fixation technique significantly reduces rotational instability and axial migration.
• The findings support the clinical evaluation of this novel nail for treating complex hip fractures.