Effect of sequential hole enlargement on cortical bone temperature during drilling of 6.2-mm-diameter transcortical holes in the third metacarpal bones of horse cadavers.

The research article investigates the impact of different drilling methods on the bone temperature and accuracy of holes created in the horse metacarpal bones. The study finds that a specific method, sequential overdrilling (SO) with 4 bits, reduced bone temperature increases during drilling without compromising the precision of the hole.

Research Methodology

• The research paper compares the results of two distinct drilling methods: sequential overdrilling (SO) and a single 6.2-mm drill bit (S6.2DB) technique.
• The study is executed in two phases, where the third metacarpal bones (MCIIIs) from 30 horse cadavers, totaling 60 specimens, are used.
• In the initial phase, the researchers compared hole diameter, tap insertion torque, peak bone temperature, and post-drilling bit temperature for 6.2-mm-diameter holes drilled in the lateral or medial cortical region of MCIIIs. They used three different 2-bit SO methods with a specific pilot hole diameter and the S6.2DB method.
• In phase 2, the researchers chose one of the SO methods from phase 1 results, compared it alongside a 4-bit SO method and S6.2DB method in drilling 6.2-mm-diameter holes. They recorded the peak bone temperature during drilling, drill bit temperature immediately following drilling, and total drilling time forComparisons.

Research Findings

• The study reveals no significant difference in the hole diameter or tap insertion torque between the two phases of the study.
• The sequential overdrilling (SO) method using four bits resulted in significantly lower temperature increases at the cortices compared to the single bit (S6.2DB) method.
• However, the 4-bit SO method led to a significantly longer drilling time than the single bit method.
• The research concluded that using a 4-bit SO method to drill in the horse metacarpal bones resulted in less temperature rise without negatively impacting the accuracy of the hole.

Research Conclusions & Implications

• The findings from this research suggest that the 4-bit SO method may be a safer way to drill holes in bone, as it produces less heat, which could potentially reduce the risk of bone damage.
• The study proves crucial in orthopedic surgery practices as high drilling temperatures can inflict thermal necrosis—cell death caused by heat—in the surrounding bone tissue, potentially leading to poor surgical outcomes.
• Even though this method implies a longer operation time, the study did not observe any measurable detriment to the precision of the drilled hole, making it a favourable choice, particularly when safety and accuracy are the primary considerations.