Investigating Torque-Speed Relationship of Self-Tapping Screws

Area of Science:

• Orthopedic biomechanics
• Biomaterials engineering
• Surgical instrumentation

Background:

• Accurate bone screw torquing is critical for successful orthopedic fixation and positive patient outcomes.
• Model-based methods are being developed to determine patient-specific bone properties and provide objective torquing recommendations.
• Modeling the bone-screwing process, particularly self-tapping screws, is essential for developing these systems.

Purpose of the Study:

• To investigate the relationship between screw insertion torque and insertion speed.
• To quantify the correlation between these parameters for potential inclusion in predictive models.
• To inform the development of more accurate, patient-specific torquing recommendations.

Main Methods:

• Investigated the relationship between screw insertion torque (Nm) and insertion speed (RPM).
• Utilized polyurethane foam as a substitute for bone material in testing.
• Analyzed data to identify correlations between torque and speed.

Main Results:

• A weak positive correlation was observed between screw insertion torque and speed at approximately 30 RPM and below.
• The study identified a relationship that warrants further investigation for inclusion in predictive models.

Conclusions:

• The relationship between screw insertion speed and torque is a significant factor to consider for accurate orthopedic modeling.
• Further research should enhance methodological precision and include ex-vivo animal bone testing.
• Accurate torque recommendations necessitate accounting for all critical factors, including insertion speed.