title: Outcome errors are not necessary for learning orthopedic bone drilling.
abstract: BACKGROUND
  When learning orthopedic bone drilling, a surgical trainee relies on internally generated and externally provided feedback. The quality and type of feedback often varies in the clinical environment, thus affecting skill acquisition. We investigated the effect of feedback on technical error (plunging) when novice surgical trainees learned bone drilling.
  
  
  METHODS
  Medical students (n = 22) and experienced postgraduate surgical residents (n = 4) drilled bicortical holes in a lamb femur under 1 of 3 feedback conditions: no feedback, self-generated feedback and externally generated feedback. Novices performed a retention test (10 bicortical holes) 1 week after the initial training. We measured plunge depth, the clinically relevant outcome, using computer-assisted methods.
  
  
  RESULTS
  During the initial experiment, the plunges of novices who were exposed to external feedback were similar to those of residents in the experienced group. Novices in the self-generated feedback group plunged more than those in the external feedback group or those in the experienced group (p = 0.002). All novices plunged similarly on the retention test, a measure of true skill learning.
  
  
  CONCLUSIONS
  When learning bicortical bone drilling, feedback related to plunging is not necessary to achieve a competent level of performance. In addition, although external feedback facilitates the achievement of better outcomes, it does not improve learning. It is suggested that to minimize plunging, trainees should learn how to optimize their drilling through the bone rather than how to prevent the plunge.
authors.affiliation: Department of Surgery, University of Toronto, Toronto, Ont.
authors.forename: Mykola
authors.initials: M
authors.lastname: Khokhotva
authors.forename: David
authors.initials: D
authors.lastname: Backstein
authors.forename: Adam
authors.initials: A
authors.lastname: Dubrowski
mesh_terms: D000818:Animals; D004521:Educational Measurement; D030141:Feedback, Psychological; D005269:Femur / Q000601:surgery*; D006801:Humans; D007396:Internship and Residency; D009864:Ontario; D019637:Orthopedic Procedures / Q000193:education*; D013337:Students, Medical