Comparing a Supine Radiologic Versus Standing Clinical Measurement of Kyphosis in Older Women: The Fracture Intervention Trial

This is the authors' abstract. We don't add key points for this paper.

In Brief Study Design. A study of agreement between different measures of kyphosis, a clinical standing measure (Debrunner kyphometer; Protek AG, Bern, Switzerland) versus a supine radiologic measure (Cobb angle). Objectives. To determine whether a supine radiologic measure of kyphosis in older women is a reasonable estimate of clinical kyphosis determined in the standing position, and to investigate a computerized assessment of the Cobb angle. Summary of Background Data. Few studies have investigated kyphosis measurement agreement involving older adults. Methods. Using data from the Fracture Intervention Trial, we randomly selected 120 women, aged 55–80 years, who had a Debrunner kyphometer measure of kyphosis and supine lateral spine radiographs from which we measured the Cobb angle (either manually or by digitization). We calculated the intraclass correlation coefficient (ICC) from repeated measures analysis of variance to assess the agreement among the: (1) manual Cobb angle and Debrunner kyphometer, (2) digitized Cobb angle and Debrunner kyphometer, and (3) manual and digitized Cobb angle. Results. The mean of both the manual and digitized Cobb angle was 45° (range 18°–83°), and the mean Debrunner kyphometer reading was 48° (range 17°–83°). The ICC between either of the 2 measures of the Cobb angle and Debrunner measurement was 0.68, indicating reasonable agreement. The ICC between the manual and digitized Cobb angle was 0.99, indicating excellent agreement. Conclusions. There is reasonable agreement between a supine radiologic and standing clinical measurement of kyphosis in older women. The degree of agreement between standing and lying measures of kyphosis in older women is not known. We compared the Cobb angle reading (performed both manually and by digitization) from supine radiographs with the standing clinical Debrunner protractor measurement and report reasonable (intraclass correlation coefficient = 0.68) to excellent (intraclass correlation coefficient = 0.99) agreement between the different measures.