Aim:. AIS causes a loss of trunk height. This paper documents this loss against sitting height standards and assesses formulae for adjusting height loss back to the standard. Methods:. A total of 334 patients (84% female) with AIS and no other known systemic disease had sitting height measured. This was compared to standards of sitting height with age and the ratio of height to sitting height with age (HSH). The corrected height was calculated using published formulae and replotted against these standards. Results:. Both sexes had significant numbers of patients under the 5th centile compared to those above the 95th centile for sitting height (p<0.05 in males and females) and for HSH centiles (p<0.05 in males and females). All formulae increased the sitting height back to within the standards. In males only the Ylikoski formula demonstrated any significant difference in sitting height and HSH. In females the Kono formula gave the least significant difference between those above and below the 95th and 5. th. centiles for sitting height and the Hwang formula for HSH. Discussion:. Scoliosis causes a loss of sitting height seen with the centile standards for sitting height and height to sitting height ratios. This can be corrected, the most accurate formula being Hwang, correcting the data to lie between the 5th and 95th centiles for sitting height with no significant difference between the number of outliers to these centiles.
