Background and purpose - Orthopedic surgeons must be able to perform internal fixation of proximal femoral fractures early in their career, but inexperienced trainees prolong surgery and cause increased reoperation rates. Simulation-based virtual reality (VR) training has been proposed to overcome the initial steep part of the learning curve but it is unknown how much simulation training is necessary before trainees can progress to supervised surgery on patients. We determined characteristics of learning curves for novices and experts and a pass/fail mastery-learning standard for junior trainees was established. Methods - 38 first-year residents and 8 consultants specialized in orthopedic trauma surgery performed cannulated screws, Hansson pins, and sliding hip screw on the Swemac TraumaVision VR simulator. A previously validated test was used. The participants repeated the procedures until they reached their learning plateau. Results - The novices and the experts reached their learning plateau after an average of 169?minutes (95% CI 152-87) and 143?minutes (CI 109-177), respectively. Highest achieved scores were 92% (CI 91-93) for novices and 96% (CI 94-97) for experts. Plateau score, defined as the average of the 4 last scores, was 85% (CI 82-87) and 92% (CI 89-96) for the novices and the experts, respectively. Interpretation - Training time to reach plateau varied widely and it is paramount that simulation-based training continues to a predefined standard instead of ending after a fixed number of attempts or amount of time. A score of 92% comparable to the experts' plateau score could be used as a mastery learning pass/fail standard.