Two Simple Tests for Adequate Needle Positioning in Vertebroplasty / 대한척추외과학회지

ABSTRACT

STUDY DESIGN: We analyzed the diagnostic values of two simple tests for adequate needle positioning in vertebroplasty. OBJECTIVES: We wanted to suggest performing the aspiration test and patency test, which can replace some of the roles of intraosseous venography (IOV) in vertebroplasty, and we also wanted to analyze the two tests' diagnostic values. SUMMARY OF LITERATURE REVIEW Intra-osseous venography is an existing safety test for vertebroplasty, but it is less frequently performed nowadays because of its drawbacks. MATERIALS AND METHODS: The aspiration test is defined as positive if blood is easily aspirated through a vertebroplasty needle, and a positive aspiration test means that the needle tip is communicating with the venous system. This and IOV were carried out on a total of 114 sides of 61 vertebrae of 40 consecutive patients. Agreement between the two tests was evaluated with using Cohen's kappa coefficient, and the diagnostic values of the aspiration test, with using IOV as the gold standard, were also evaluated. The patency test is done in the intra-vertebral vacuum cleft cases. After bipedicular insertion of needles, saline is injected into one needle. If the saline gushes out of the other needle, the test is positive, and it means that both needles are inserted in the vacuum cleft. The patency test was performed in 25 vertebrae, and the positive rate and causes of the negative result were investigated. RESULTS: Cohen's kappa coefficient between the aspiration test and IOV was 0.88. The sensitivity of the aspiration test was 88%, the specificity was 99%, the positive predictive value was 97%, and the negative predictive value was 93%. The patency test was positive in 88% of the vacuum clefts. In all the positive cases, both needles were located within the vacuum cleft. In all the negative cases, one of the two needles was located outside the cleft. CONCLUSIONS: The aspiration test is a simple and reliable test that has high agreement with IOV. The patency test can be a better choice than IOV for the vacuum cleft cases because it does not leave contrast media in the clefts.