Pull-Force Generated by the Revolving High-speed Drill Shaft Results in Unexpected Tissue Wrapping Around the Shaft.

Despite holding soft tissue away from high-speed drills during surgery, tissue can unexpectedly wrap around the drill shaft. We performed experiments to examine what precipitates such mishaps. In a windless environment, a Signature Drill System (Stryker) featuring a 4-mm diameter coarse diamond or cutting bit was placed parallel to a suspended strip of polypropylene. The distance between the end of the strip and the drill shaft or bits was 4 or 8 mm. In another experiment, we placed the drill horizontally 10 mm above the top of dry-ice fog. The maximum drill speed was 75,000 rpm, and the horizontal motion of the polypropylene strip and the vertical motion of the dry-ice fog were recorded by a video camera. In the experiments, the strip parallel to the vertical shaft and the dry-ice fog were pulled toward the shaft; the higher the revolving drill speed, the faster its motion. On the other hand, in experiments where the end of the strip was next to either bit, no such motion was observed. The pulling force generated by revolving high-speed drill shafts may result in tissue wraparound even when soft tissue is held away from the shaft. [ABSTRACT FROM AUTHOR]