Sadowitz et al: Effect of screw insertion angle and speed on the incidence of transcortical fracture development in a canine tibial diaphyseal model
Veterinary Surgery 8, 2023

🔍 Key Findings

• TCF risk increased significantly with 10° insertion angle at both 650 rpm (12.5%) and 1350 rpm (17.5%), compared to 0% in the control group (0° at 650 rpm).
• Hand insertion at 10° angle resulted in only 3.75% TCF rate, suggesting lower insertion speed reduces risk.
• No TCFs occurred when screws were inserted coaxially (0°) at either 650 or 1350 rpm, indicating angle is a critical factor.
• Screw speed alone did not increase TCF risk unless combined with off-axis insertion.
• Radiographically detectable TCFs were only considered; actual rates may be higher with direct bone inspection.
• Cutting flutes engaging undrilled bone during off-axis insertion likely contribute to TCF formation.
• Clinical implication: Ensure screws are inserted coaxially and at lower speeds to reduce TCF risk during procedures like TPLO.
• Statistically significant differences were found between control and high-angle insertion groups: Group C (p = .001), Group E (p < .001).