Assessment of vertebral fractures in osteoporosis research

The evaluation of conventional radiographs of the spine for vertebral fractures is an important component of clinical practice and research in osteoporosis. Aside from the traditional approach of qualitative assessment of spinal radiographs 2 additional approaches have evolved, particularly for applications in clinical research and epidemiological studies. The first is quantitative morphometry (QM), which is based upon measurement of 4-10 points on the lateral projection of the vertebral body and determination of vertebral heights and ratios of heights. QM is a definable, describable, and relatively reproducible method for detecting both prevalent and incident fractures. However, projectional effects substantially influence the reliability of these measures performed in isolation. Therefore, there has been renewed interest in the visual assessment of fractures using a semiquantitative assessment (SQ) grading scale with definable, morphological and morphometric criteria. This second approach, while perhaps not as objective as QM, makes use of all the information regarding vertebral size and shape and is fundamentally more complex. When performed with adequate training, however, it provided good reproducibility and reliability. This overview provides a brief analysis of the methodologies and the advantages and disadvantages of the QM and SQ approaches, and compares their relative performance, alone or combined, in a large prospective population based study.