Biomechanical study of space frame structure based on bone cement screw.

Area of Science:

• Orthopedic biomechanics
• Spinal surgery
• Materials science in medicine

Background:

• Osteoporosis severely compromises vertebral bone strength, increasing the risk of spinal fractures and instability.
• Current internal fixation methods may lack sufficient stability in osteoporotic spines, leading to complications.
• Bone cement augmentation is used, but its optimal application for screw reinforcement needs further investigation.

Purpose of the Study:

• To evaluate the biomechanical stability of space frame structures reinforced with bone cement screws in osteoporotic human spine specimens.
• To compare the stability of bridged versus non-bridged bone cement screw configurations.
• To assess the effectiveness of this technique for improving internal fixation in severe spinal disease.

Main Methods:

• Biomechanical testing of seven human spine specimens with induced osteoporosis.
• Preparation of single vertebral and multi-vertebral groups with variations in bone cement screw bridging.
• Analysis of screw extractive force and overall structural stability.

Main Results:

• A statistically significant difference in extractive force was observed between bridged and non-bridged specimens.
• Non-bridged screw configurations (Group B) exhibited screw loosening post-testing.
• Bridging the bone cement screws created a stable triangle structure, significantly enhancing stability in both single and multi-vertebral models.

Conclusions:

• Establishing a bone cement bridge at the front end of bone cement screws significantly enhances the stability of spinal internal fixation.
• The three-dimensional frame structure formed in the multi-vertebral group demonstrated markedly improved stability.
• This technique offers a promising new method for improving the stability and reliability of internal fixation in patients with severe osteoporosis and spinal disease.