Skill Assessment in the Interpretation of 3D Fracture Patterns from Radiographs.

Background: Interpreting two-dimensional radiographs to ascertain the three-dimensional (3D) position and orientation of fracture planes and bone fragments is an important component of orthopedic diagnosis and clinical management. This skill, however, has not been thoroughly explored and measured. Our primary research question is to determine if 3D radiographic image interpretation can be reliably assessed, and whether this assessment varies by level of training. A test designed to measure this skill among orthopedic surgeons would provide a quantitative benchmark for skill assessment and training research.

Methods: Two tests consisting of a series of online exercises were developed to measure this skill. Each exercise displayed a pair of musculoskeletal radiographs. Participants selected one of three CT slices of the same or similar fracture patterns that best matched the radiographs. In experiment 1, 10 orthopedic residents and staff responded to nine questions. In experiment 2, 52 residents from both orthopedics and radiology responded to 12 questions.

Results: Experiment 1 yielded a Cronbach alpha of 0.47. Performance correlated with experience; r(8) = 0.87, p<0.01, suggesting that the test could be both valid and reliable with a slight increase in test length. In experiment 2, after removing three non-discriminating items, the Cronbach coefficient alpha was 0.28 and performance correlated with experience; r(50) = 0.25, p<0.10.

Conclusions: Although evidence for reliability and validity was more compelling with the first experiment, the analyses suggest motivation and test duration are important determinants of test efficacy. The interpretation of radiographs to discern 3D information is a promising and a relatively unexplored area for surgical skill education and assessment. The online test was useful and reliable. Further test development is likely to increase test effectiveness.

Clinical Relevance: Accurately interpreting radiographic images is an essential clinical skill. Quantitative, repeatable techniques to measure this skill can improve resident training and improve patient safety.