The prevalence of posticus ponticus: retrospective analysis of radiographs from a chiropractic health center

ObjectiveThe potential clinical significance of posticus ponticus is controversial because the majority of patients with this finding are asymptomatic. This study sought to estimate the prevalence of posticus ponticus in a chiropractic college clinic patient population.MethodsFrom the archived records in the College Health Center, 304 lateral cervical spine radiographs were randomly selected and assessed by 2 independent examiners for the presence of posticus ponticus in any of its forms. The number of radiographs showing posticus ponticus, as well as analysis of agreement between examiners, was obtained.ResultsThere were 60 radiographs where the examiners disagreed as to the presence or absence of posticus ponticus. These 60 were not counted for prevalence of posticus ponticus but were included in the κ analysis. Among the remaining 246 radiographs, 112 (46%) showed some type of posticus ponticus, whereas 132 (54%) did not show any posticus ponticus finding. Examiners A and B showed a κ score agreement of 0.72, and examiners C and D showed a κ score agreement of 0.51.DiscussionThe κ scores for both sets of examiners show acceptable agreement. Within this population, the finding of 45.9% prevalence of some type of posticus ponticus was determined. Compared with other studies, the prevalence of posticus ponticus was found to range between 9% and 72%.ConclusionWithin this sample, 45.9% of radiographs showed some type of posticus ponticus.