The clinical influence of fluid sign in treated vertebral bodies after percutaneous vertebroplasty.

PURPOSE

To determine the association between fluid sign and clinical prognosis following percutaneous vertebroplasty (PV).

MATERIALS AND METHODS

Institutional review board approval and informed consent were obtained for this prospective study. Fifty-two patients (41 women, 11 men; mean age, 75.9 years; range, 56-95 years) were enrolled from August 2006 to August 2007. All patients underwent preoperative magnetic resonance (MR) imaging and assessment of mobility and pain scores. PV was performed and patients underwent 1-, 3-, and 6-month follow-up examinations. MR findings of fluid sign (a focal, linear, or triangular area of strong hyperintensity, which is isointense relative to cerebrospinal fluid on T2-weighted sagittal images) and vacuum cleft were analyzed with respect to clinical outcome. Data were analyzed by using a combination of independent Student t test, chi(2) test, analysis of variance, and Fisher exact test.

RESULTS

Thirty-four (65%) patients showed vacuum cleft; 14 (27%) showed fluid sign at the bone-cement interface. Patients without fluid sign in the treated vertebral bodies had better mobility and pain improvement compared with patients with fluid sign at 1- and 3-month follow-up (P < .05). The adjacent fracture percentage (seven of 14, 50%) was higher in patients with fluid sign in the treated vertebral bodies than in those without (three of 38, 8%) (P = .002). Pain was similar in groups with and without fluid sign at 6-month follow-up.

CONCLUSION

The fluid sign in the treated vertebral bodies had a high negative predictive value of 92% and a positive predictive value of 50% to develop a new adjacent compression fracture.