Construct Validation of a Printed Bone Substitute in Otologic Education

: Patient safety demands enhancements in training. Graduated cadaveric bone exposure is fundamental to otologic training. Printed bone models (PBM) provide a low-cost, anatomically consistent adjunct to cadaveric materials in trainee skill acquisition.The purpose of this study is to determine if resident training level can be distinguished on the basis of performance employing a printed temporal bone model, graded by a previous validated scale.

Nineteen residents (11 male, 8 female) from 9 graduate programs, attending a National Otolaryngology Conference, completed a mastoidectomy with posterior tympanotomy on identic 3D PBMs and a Likert scale (1-7) survey on subjective appreciation of the simulation. Four experts graded participant performance using the previously validated Welling Scale.

ANOVA revealed significant performance differences between the junior/intermediate and junior/senior PGY cohorts. No difference was observed between intermediate/senior cohorts on the basis of PGY or subjective temporal bone dissection experience. Clustering aspects of the scale with specific focus on thinning tasks found a similar outcome to the composite scale scores.Subjective experience judged printed bone to be similar to cadaveric in drill-bone interaction. Participants believed the simulation would improve surgical performance, comfort with actual patients, and operative speed.

Subjectively, printed bone compared favorably to cadaveric.The simulation demonstrated construct validity but was challenged in differentiating senior from intermediate trainee performance. This may be a function of the PBM inherent character, limitations in grading instrument fidelity or sample size. It is also possible that the dominant period of skill acquisition for mastoidectomy and posterior tympanotomy are primarily acquired during the junior training.