School screening for scoliosis: the value of quantitative measurement

Several studies advocate quantification of the bending test or performing surface topography to reduce the referral rate and to increase the specificity of the bending test in screening for scoliosis. Within the framework of a school screening project all children with a positive bending test were reexamined with measurement of rib hump height, angle of trunk rotation and moiré topography. In the period 1983-1986, out of three cohorts of 10,000 children of 10, 12 and 14 years of age, 3,069 were reexamined, of whom 1931 again tested positive (63%). The value of the three techniques in terms of sensitivity and specificity within the reexamined group was evaluated with regard to the Cobb angle on a spinal radiograph, which was made in 671 cases. A reduction in referrals of 37% was found. No significant difference in the ability to detect scoliosis was found between the three techniques mentioned. It is concluded that measurement techniques are valuable in school screening programmes. In particular, if instead of a single cut-off value, a range within which the examination should be repeated is chosen, high sensitivity and high specificity can be combined. Angle of trunk rotation measurement seems to be the easiest method of screening.