Prediction of thoracic kyphosis using the Debrunner kyphometer

The Debrunner kyphometer is an accepted tool for detecting and evaluating t horacic kyphosis. This prospective study was conducted to create a mathemat ical formula that provides, with high approximation, the roentgenographic a ngle of thoracic kyphosis (T4-T12) using only the kyphometer. Several clini cal (kyphometer value, age, and sex) and radiographic (Cobb angle [T4-T12]) parameters from 90 consecutively screened adolescents (44 male and 46 fema le) were correlated using simple and multiple linear regression analyses. T he reliability of measurement using the Debrunner kyphometer was high. The kyphometer value was strongly correlated with the roentgenographically meas ured thoracic Cobb angle (simple linear regression analysis; probability ra nge, 0.0026 to 0.0002). There was no correlation between age or sex and tho racic kyphosis The predicted kyphosis angle using the kyphometer and the ma thematic formula was 44.66 degrees +/- 2.68 degrees, (range 27 to 62 degree s), and the real roentgenographic kyphosis angle was 47.5 degrees +/- 3.53 degrees, (range, 24 to 70 degrees). The kyphometer and formula were more re liable and accurate when kyphosis less than 50 degrees was measured. In thi s study, the authors constructed a mathematical formula that accurately pro vides the roentgenographic T4-T12 hyphosis angle in adolescents using only the Debrunner kyphometer with a deviation of less than 3 degrees. The autho rs recommend that all physicians engaged in kyphosis screening programs use the kyphometer combined with the recently constructed simple mathematic fo rmula. This method will reduce the cost of school screening programs, overd iagnoses, and unnecessary exposure of adolescents to irradiation.