Radiographic detection of single-leg fracture in Bjork-Shiley Convexo- Concave prosthetic valves: A phantom model study

Cineradiography can identify patients with single-log fractured Bjork- Shiley Convexo-Concave valves, although little is known about the sensitivity and specificity of this technique. We evaluated three normal and six (0 μm gap) single-leg fractured Bjork-Shiley valves that were placed in a working phantom model. Valves were randomly imaged a total of 33 times and duplicated into a 120-valve series with a 1:9 ratio of abnormal/normal valves. Six reviewers independently graded each valve and demonstrated markedly different rates of identifying the fractured valves. Average sensitivity at the grade that clinically results in valve explanation was 47%. Among the normal valves, a correct identification was made 96% (range 91% to 99%) of the time. Present radiographic technology may have significant difficulty in identifying true single-leg fracture In Bjork-Shiley valves with limb separations that are common among clinically explanted valves.