The accuracy of radiographic evidence demonstrating improvements in vertebral alignment attributed to upper cervical chiropractic interventions hinges on the precise, repeated x-ray positioning of patients before and after the intervention.1-4 Radiographic distortions due to patient positioning errors compromise the accuracy of subsequent procedures used to measure spinal alignment and, further, the validity of comparing these measurements to demonstrate improvements following the intervention. 1,3,5 Although studies addressing the reliability of these measurement procedures present favorable results, this issue regarding positioning distortions dilutes these results’ significance and questions the widespread practice of post-intervention radiography in upper cervical chiropractic practices.1-4,6
In this study, we aim to describe a new procedure designed to measure patient-positioning precision itself—specifically, the ability to repeat the patient’s x-ray positioning following the intervention. Through digital analysis of pre- and post-intervention matched pairs of x-rays, the procedure yields various metrics related to the degree of similarity in the relative position of relevant skeletal landmarks when comparing pre- and post-films. We then present reliability statistics for this procedure, derived from two independently blinded evaluations of 80 such x-ray sets by a single analyst. To acquire these x-ray samples, we specifically solicited 8 NUCCA (National Upper Cervical Chiropractic Association) practitioners with varying levels of experience, allowing us to present statistics that describe the general variability in patient-positioning precision among this group (as measured by this new method), as well as any correlation between positioning precision and practitioner experience. Through extrapolation, these findings may provide a reasonably accurate assessment of the current standard of care regarding patient-positioning by NUCCA practitioners; further, they may serve as a basis to either accept or reject this conventional use of post-adjustment radiography.
The study’s data have been collected and thoroughly analyzed, and the findings are currently being prepared for publication.
