The accuracy of computerized biophotogrammetry in diagnosing changes in the cervical spine and its reliability for the cervical lordosis angle

BACKGROUND: Accuracy studies of biophotogrammetry protocols require standardization similar to radiography. OBJECTIVE: To estimate the diagnostic accuracy of a biophotogrammetric assessment protocol for cervical hyperlordosis, compared to radiography, and its intra- and inter-examiner reliability for measuring the cervical lordosis angle. METHODS: A study of diagnostic accuracy in women complaining of cervical pain. Two photos were taken using the Corel-Draw biophotogrammetric protocol and one radiograph using the Cobb C1-C7 method. The Intra- and Inter-examiner reliability was calculated using the Kappa index and the intraclass correlation coefficient (ICC). The Bland-Altman plot and the ROC curve were presented. RESULTS: The sample consisted of 19 women. The accuracy of biophotogrammetry was 94.73% and the reliability between biophotogrammetry and radiography presented an ICC of 0.84 and a Kappa of 0.87. The excellent intra (ICC = 0.94) and inter-examiner (ICC = 0.86) reliability of the biophotogrammetry was confirmed. The area under the ROC curve was 93.5%. The Bland-Altman plot indicated differences between the two instruments close to the mean (1.5 degrees). CONCLUSION: The biophotogrammetric protocol proved to be accurate in diagnosing cervical hyperlordosis, with excellent reliability between the biophotogrammetric and radiographic assessments. It also demonstrated excellent intra- and inter-examiner reliability in measuring the cervical lordosis angle.