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Updated: Dec 24, 2025
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An Anesthesia, Surgery, and Harvest Method for the Evaluation of Transpedicular Screws Using an In Vivo Porcine Lumbar Spine Model
Published on: May 31, 2017
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Drilling Energy Correlates With Screw Insertion Torque, Screw Compression, and Pullout Strength: A Cadaver Study
Michael J Chen1, Malcolm R DeBaun, Timothy Thio
1From the Department of Orthopaedic Surgery, Stanford University Medical Center, Redwood City, CA.
Summary
Drilling energy measurements correlate better with screw insertion torque and pullout strength than bone mineral density in cadaver bone. This dynamic measure may help surgeons assess bone quality before implant surgery.
Area of Science:
- Orthopaedic Surgery
- Biomedical Engineering
- Materials Science
Background:
- Assessing bone quality is crucial for successful orthopaedic implant procedures.
- Current methods like bone mineral density (BMD) may not fully represent bone's mechanical properties for screw fixation.
Purpose of the Study:
- To investigate the correlation between drilling energy and key bone fixation parameters.
- To compare drilling energy's predictive power against BMD for screw insertion torque and pullout strength.
Main Methods:
- Drilling energy was measured during pilot hole creation in 10 cadaver tibias.
- Bone quality was assessed using microcomputed tomography.
- Screw insertion torque (MIT) and pullout strength (POS) were evaluated.
Main Results:
- Drilling energy showed a significant correlation with bone mineral density (BMD).
- Drilling energy demonstrated stronger correlations with maximum insertion torque (MIT), maximum screw compression, and pullout strength (POS) compared to BMD.
- Maximum screw compression also correlated with MIT.
Conclusions:
- Drilling energy is a more effective indicator of bone quality for screw fixation than BMD in cadaveric cortical bone.
- Dynamic measurement of drilling energy offers a potential real-time assessment tool for surgeons to guide implant placement.
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