title: Comparison of cortical bone drilling induced heat production among common drilling tools.
abstract: OBJECTIVE
  Significant data exist regarding heat production of twist drills; however, there are little data regarding cannulated drills or Kirschner (K) wires. This study compared the heat produced during bone drilling with twist drills, K wires, and a cannulated drill. It was hypothesized that drilling temperature would increase with tool sizes used in orthopaedic surgery; with twist drills producing the least amount of heat followed by cannulated drills and K wires.
  
  
  METHODS
  Twist drills (2.0, 2.5, and 3.5 mm), K wires (1.25, 1.6, and 2.0 mm), and a cannulated drill (2.7 mm) were driven into warmed human cadaveric tibia by a battery-powered hand drill. The drill was secured on a servo-controlled linear actuator to provide a constant advancing speed (1 mm/s) during drilling. Two thermocouples were embedded 2 mm from the surface at 0.5 and 1.5 mm from the drill hole margin. Eight tests were performed for each tool.
  
  
  RESULTS
  Twist drills exhibited a positive trend between size and heat production. The size effect was less significant with K wires. K wires resulted in significantly (P = 0.008 at 0.5 mm) higher peak temperatures than twist drills of the same size. A 2.7-mm cannulated drill produced more than double the temperature rise of a 2.5-mm twist drill.
  
  
  CONCLUSIONS
  Twist drills produced the smallest temperature rise among all bit types. Thermal effects should not be a reason for choosing K-wire size. The cannulated drill showed significantly higher temperatures when compared with standard drills, reaching maximal temperatures comparable with K wires.
authors.affiliation: Departments of *Orthopaedic Surgery; †Mechanical Engineering, and ‡Biomedical Engineering, University of Michigan, Ann Arbor, MI.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Palmisano
authors.forename: Bruce L
authors.initials: BL
authors.lastname: Tai
authors.forename: Barry
authors.initials: B
authors.lastname: Belmont
authors.forename: Todd A
authors.initials: TA
authors.lastname: Irwin
authors.forename: Albert
authors.initials: A
authors.lastname: Shih
authors.forename: James R
authors.initials: JR
authors.lastname: Holmes
mesh_terms: D000328:Adult; D000368:Aged; D001864:Bone Wires; D001842:Bone and Bones / Q000601:surgery*; D002102:Cadaver; D005260:Female; D006358:Hot Temperature; D006801:Humans; D008297:Male; D008875:Middle Aged; D009983:Orthopedic Equipment; D013977:Tibia / Q000601:surgery*; D055815:Young Adult