Vertebral fracture assessment in supine position: comparison by using conventional semiquantitative radiography and
Ilone C Hospers1, Johan G van der Laan, Clark J Zeebregts
1Department of Surgery, University Medical Center Groningen, University of Groningen, Hanzeplein 1, PO Box 30001, 9700 RB Groningen, the Netherlands.
Purpose:
To retrospectively evaluate the accuracy of vertebral fracture assessment (VFA) performed with the patient in the supine position and conventional semiquantitative radiography of the spine by using conventional visual radiography of the spine as the reference standard.
Materials And Methods:
This retrospective study was approved by the institutional ethics review board; informed consent was obtained from the patients. A total of 250 consecutive patients (mean age, 62.0 years; range, 25-89 years) consisting of 190 women (mean age, 64 years; range, 25-89 years) and 60 men (mean age, 57.0 years; range, 27-83 years) who were suspected of having osteoporosis and who underwent VFA in the supine position and radiography of the spine were evaluated. VFA and semiquantitative radiography were analyzed by using a six-marker point method to describe the shape and deformity of each vertebra. Visual radiography of the lateral spine was performed by an experienced radiologist. The agreement between VFA, visual radiography, and semiquantitative radiography of semiquantitative graded fractures was assessed by using weighted kappa statistics.
Results:
Visual radiography helped identify 92 (36.8%) patients with at least one vertebral fracture (mean, 1.8 per patient). Most fractures were present in T7, T12, and L1. Excellent agreement was found between VFA and visual radiography, with 97.5% concordance and kappa = 0.82; VFA and semiquantitative radiography were in agreement in 97.4% of patients, with kappa = 0.83; and visual radiography and semiquantitative radiography were in agreement in 98.1%, with kappa = 0.87. Sensitivity, specificity, and positive and negative predictive values calculated by lesion level for VFA compared with visual assessment were 83.6%, 99.1%, 84.1%, and 99.1%, respectively.
Conclusion:
VFA performed with patients in the supine position is an accurate method to help detect vertebral fractures when compared with conventional spine radiography. VFA permits combination of fracture assessment with bone mineral density measurement in a single session.