The purpose of this study was to classify the patterns of cement leakage that occurs during vertebroplasty for osteoporotic compression fractures, to evaluate the diagnostic values of simple radiographs for detecting leaks, and to find signs on simple radiographs that suggest leaks into the spinal canal.

First, leakage was classified based on the findings of CT scans and radiographs of 76 vertebrae in 49 patients. Second, the diagnostic values of simple radiographs for detecting leaks were evaluated by comparing the results of a review of simple radiographs with those of CT scans. Finally, warning signs of leakage into the spinal canal on lateral views were identified, and their positive predictive values assessed.

Cement leaks were classified into three types according to their routes. Only 66% (50/76) of all leaks were found on simple radio-graphs. Of these, only 8% (2/25) of leaks into the spinal canal were correctly interpreted. Among the four identified warning signs, cement in the neural foramina was found to have the highest positive predictive value (86%).

Since the sensitivity of radiographs for detecting leakage into the spinal canal is low, careful attention should be paid to identify it early. The four suggested warning signs help early detection.