RELIABILITY OF SPINAL DISPLACEMENT ANALYSIS ON PLAIN X-RAYS - A REVIEW OF COMMONLY ACCEPTED FACTS AND FALLACIES WITH IMPLICATIONS FOR CHIROPRACTIC EDUCATION AND TECHNIQUE

Background: Current medical, biomechanical, and chiropractic literatur e indicates that X-ray line drawing analysis fur spinal displacement i s reliable, with high Interclass Correlation Coefficients (ICCs) found in most studies. Normal sagittal spinal curvatures an being accepted as important clinical outcomes of care; however, just the opposite is taught in many chiropractic college radiology courses. Objective: To r eview the current literature on X-ray line drawing reliability and abn ormal static lateral positions. Data Sources: Searches were performed on Medline, Chiro-LARS, MANTIS, and CINAHL on X-ray reliability, norma l spinal position, and sagittal spinal curvatures as clinical outcomes . Results: X-ray line drawing analysis for spinal displacement was fou nd to have high reliability with a majority of ICCs in the .8-.9 range . The reliability for determining X-ray pathology was found to be only fair to good by both medical doctors and chiropractors and by both ch iropractic and medical radiologists, with a majority of ICCs in the ra nge .40-.75. Muscle spasms, facet hyperplasia, short pedicles and pati ent positioning errors have not been shown to alter sagittal plane ali gnment. The sagittal spinal curves are desirable clinical outcomes of care in surgery, physical therapy, rehabilitation and chiropractic. Th ese results contradict common claims found in the indexed literature, Conclusion: X-ray line drawing is reliable. Normal values for the sagi ttal spinal curvatures exist in the literature. The normal sagittal sp inal curvatures are important clinical outcomes of care. Patient posit ioning and postural radiographs are highly reproducible. When these st andardized procedures are used, the pre-to-post alignment changes are a result of treatment procedures applied. Chiropractic radiology educa tion and publications should reflect the recent literature, provide mo re support for X-ray line drawing analyses and applications of line dr awing analyses for measuring spinal displacement on plain radiographs.