Structural stability of different reconstruction techniques following total sacrectomy: a biomechanical study

Area of Science:

• Spinal surgery
• Orthopedic biomechanics
• Reconstructive surgery

Background:

• Biomechanical stability of the spino-pelvis structure after total sacrectomy is not well understood.
• Various reconstruction techniques exist, but their comparative efficacy is unclear.

Purpose of the Study:

• To compare the structural stability of different spino-pelvis reconstruction techniques following total sacrectomy.

Main Methods:

• Six human cadavers underwent total sacrectomy and reconstruction using four methods: sacral rod, bilateral fibular flap, four-rod, and improved compound reconstruction.
• Biomechanical stability was assessed by measuring ranges of motion, L5 displacement, abduction, and sagittal rotation under axial loading.
• Overall stiffness was determined using load-displacement curves.

Main Results:

• Improved compound reconstruction demonstrated significantly higher stiffness than the other three techniques.
• Bilateral fibular flap reconstruction provided superior stability compared to sacral rod reconstruction.
• Four-rod reconstruction exhibited the least stability due to the absence of anterior bracing.

Conclusions:

• Improved compound reconstruction yields optimal structural stability after total sacrectomy.
• Anterior bracing and optimized screw trajectory are key factors for achieving superior biomechanical stability in these reconstructions.