Osteoporotic vertebral fractures: diagnosis with radiography and bone scintigraphy.

Objective: To determine the radiographic appearance of osteoporotic vertebral fracture.

Methods: Lateral thoracic and lumbar spine radiographs were examined in 58 patients (812 vertebra) with osteoporosis and evidence of vertebral collapse at bone scintigraphy. Scintigraphic activity was graded as faint, moderate, or intense. Anterior, middle, and posterior heights of the T-4 to L-5 vertebrae were measured. The degree of vertebral deformity was derived by comparing a ratio of heights with the normal mean.

Results: At radiography, 378 of the 812 vertebrae (47%) were normal, 434 (53%) had deformities that were more than two standard deviations (SDs) below the normal mean, 304 (37%) had deformities that were more than three SDs below the normal mean, and 222 (27%) had deformities that were more than four SDs below the normal mean. Of 86 vertebrae that showed moderate or intense radionuclide uptake at scintigraphy, all had deformities that were more than two SDs below the normal mean, and 80 (93%) had deformities that were more than three SDs below the normal mean.

Conclusions: Only in vertebrae with deformities more than three SDs below the normal mean can fractures be confidently diagnosed.