A simple radiological method for recognizing osteoporotic thoracic vertebral compression fractures and distinguishing them from Scheuermann disease.

STUDY DESIGN

Blinded.

OBJECTIVE

Examination of a new radiologic interpretation technique for distinguishing osteoporotic fractures from Scheuermann disease. STUDY OF BACKGROUND DATA: Osteoporotic vertebral fractures are a major clinical problem. A variety of empirically-derived standards have been suggested for their recognition, but the accepted limits for normal variation have been somewhat arbitrary. This report presents and examines a new radiologic technique for distinguishing osteoporotic thoracic vertebral fractures from Scheuermann disease.

METHODS

Vertebral body height measurements (anterior, middle, and posterior) of thoracic vertebrae T6-T10 in 44 individuals with osteoporotic fractures, 28 individuals with Scheuermann disease and a control group of 120 individuals with unaffected vertebrae, were taken from lateral chest radiographs and measured by a digital caliper. For each vertebra, 4 indexes were calculated: 3 primary derivatives; anterior height/posterior height; anterior height/mid height (A/M); mid height/posterior height (M/P); and a secondary derivate index (A/M)/(M/P). Qualitative analysis was subsequently carried out, using lateral spine radiographs of individuals with osteoporotic vertebral fractures and individuals with Scheuermann disease. Statistical analysis included analysis of variance, paired t tests and t tests.

RESULTS

The second derivative (A/M)/(M/P) indexes of thoracic vertebrae T6-T10 were significantly greater in the osteoporosis group than in the control and Scheuermann groups (P < 0.05). Contrary to the control and Scheuermann groups, the M/P indexes (T6-T10) were significantly smaller than the A/M indexes in the osteoporosis group. The anterior height/posterior height indexes (T6-T10) in all 3 groups were statistically indistinguishable. Qualitative analysis showed that the intersection of an anterior-midpoint line and a posterior-midpoint line drawn on the superior vertebral body surface (T6-T10) created an "angle of depression" in the osteoporosis group whereas an "angle of elevation" was identified in the Scheuermann group.

CONCLUSION

Second derivative indexes of vertebral body height parameters allow identification of vertebrae with osteoporotic compression fractures and their distinction from vertebrae with Scheuermann disease.