title: Precision of wear measurement using the shadowgraph technique.
abstract: The shadowgraph technique is a relatively easy-to-use and inexpensive method of wear measurement from explanted acetabular cups. In this technique, from a mould of the internal surface of the cup, measurements of linear wear and wear angle can be obtained, from which volumetric wear can be calculated. In this study the measurement precision of this technique was assessed and the influence of different observers and multiple moulds was also determined. It was found that linear wear (coefficient of variation (CV) = 1.49 per cent) can be more precisely determined than wear angle (CV = 8.18 per cent) and that both the observer and the mould can significantly influence the results obtained, although the influence of the mould is considerably less than that of the observer.
authors.affiliation: Department of Orthopaedic Surgery, University of Bristol, and Research and Development Support Unit, United Bristol Healthcare Trust, UK. j.l.cunningham@bath.ac.uk
authors.forename: J L
authors.initials: JL
authors.lastname: Cunningham
authors.forename: I
authors.initials: I
authors.lastname: Bisbinas
authors.forename: R
authors.initials: R
authors.lastname: Greenwood
authors.forename: I D
authors.initials: ID
authors.lastname: Learmonth
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis / Q000379:methods*; D006622:Hip Prosthesis; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D010781:Photography / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013499:Surface Properties