Document Type

Dissertation

Date of Degree

Spring 2014

Degree Name

PhD (Doctor of Philosophy)

Degree In

Industrial Engineering

First Advisor

Geb W. Thomas

Abstract

Standard surgical repair of intertrochanteric hip fractures requires accurate placement of a wire across the fracture using static fluoroscopic images. Few practice methods exist for perfecting this wire navigation skill outside the operating room. The objective of this research is to further understand skill development for orthopaedic drilling using a validated simulator, enabling more effective instruction and training. This includes the investigation of the relationship between practice and skill acquisition in conjunction with specific differences between experts and novices.

This work details the creation and validation of an augmented reality wire navigation simulator for training orthopaedic drilling. This novel augmented reality simulator combines real-world objects, such as a surgical drill and synthetic bone, with virtually generated, radiation-free radiographic imaging. The central hypothesis is that an augmented reality wire navigation simulator will demonstrate construct validity and improve orthopaedic drilling skill through simulation training.

This work identifies the differentiation of skill between experienced surgeons and novices completing the wire navigation task, demonstrating construct validity for the developed simulator. It also demonstrates that experienced surgeons are more accurate than novices in orthopaedic drilling (F(2, 39) = 3.721, p = 0.033). This provides evidence supporting the simulator's construct validity and value as a training and assessment tool in wire navigation of the proximal femur.

Although the study was unsuccessful in providing sufficient evidence that training on the simulator directly transfers to more realistic drilling tasks, it revealed several discoveries about acquiring wire navigation skill. This work establishes a relationship between skill acquisition and practice for the wire navigation task. This learning curve shows that skill acquisition occurs much more slowly in wire navigation than previously assumed. The wire accuracy (i.e., tip-apex distance) is predicted to improve 0.1 to 0.3 millimeters with each successive practice repetition of the wire navigation task (95% CI, p < 0.001). In addition, the time to complete wire navigation improves between 0.4 and 2.0 seconds each subsequent practice trial (95% CI, p < 0.001).

The developed simulator also identified several flaws in novice technique. First, novices do not account for the anteversion of the femoral neck indicating that the inclination angle is difficult for novices to understand and accurately drill from radiographic images. Another discovered flaw of novice orthopaedic residents is their lack of ability to accurately estimate distances in radiographic images. Novices were found to incorrectly estimate the wire accuracy by an average of 12.4 millimeters. Overall, this work establishes new findings, which can be used for future simulation development and coaching, enabling safer, more effective training methods for surgical residents.

Keywords

Augemented Reality, Development, Orthopaedics, Simulation, Training, Validation

Pages

xii, 156 pages

Bibliography

Includes bibliographical references (pages 145-156).

Copyright

Copyright 2014 Brian Douglas Johns

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