Cement leakage in percutaneous vertebroplasty for osteoporotic vertebral compression fractures: identification of risk factors

BACKGROUND CONTEXT: Percutaneous vertebroplasty (PVP) is a common treatment modality for painful osteoporotic vertebral compression fractures (OVCFs). The complication rate of PVP is low, but cement leakage occurs in up to 90% of the treated levels. Recent evidence suggests that sequelae of cement leakage may be more common and clinically relevant than previously thought. Preoperative appreciation of risk factors would therefore be helpful but has not been thoroughly investigated. PURPOSE: Identification of preoperative risk factors for the occurrence of cement leakage in PVP for painful OVCFs. STUDY DESIGN: Retrospective assessment of risk factors using multivariate analysis. PATIENT SAMPLE: Eighty-nine patients treated with PVP for 177 painful OVCFs. OUTCOME MEASURE: Occurrence of cement leakage. METHODS: The influence of all known risk factors and other parameters potentially affecting the occurrence of cement leakage was retrospectively assessed using multivariate analysis. Patient age, sex, and spinal deformity index; fracture age, level, type, and semiquantitative severity grade (1-4), the presence of an intravertebral cleft and/or cortical disruption on preoperative magnetic resonance imaging (MRI), and the viscosity of bone cement were included. Cement leakage was assessed on direct postoperative computed tomography scanning of the treated levels. In addition to cement leakage in general, three fundamentally different leakage types (cortical, epidural, and anterior venous), with different possible clinical sequelae, were discerned, and their respective risk factors were assessed. RESULTS: In 130 of 173 (75.1%) treated OVCFs, cement leakage was detected. Leakage incidence was found to increase approximately linear with advancing severity grade. High fracture semiquantitative severity grade (adjusted per grade relative risk [RR], 1.14; 95% confidence interval [CI], 1.05-1.24; p=.002) and low bone cement viscosity (medium vs. low viscosity: adjusted RR, 0.73; 95% CI, 0.61-0.87; p<001) were strong risk factors for cement leakage in general. For cortical leakage (in 95% intradiscal leakage), the presence of cortical disruption on MRI (adjusted RR, 1.62; 95% CI, 1.16-2.26; p=.004) and an intravertebral cleft on MRI (adjusted RR, 1.43; 95% CI, 1.07-1.77; p=.017) were identified as additional strong risk factors. CONCLUSIONS: High fracture severity grade and low viscosity of polymethylmethacrylate bone cement are general, strong, and independent risk factors for cement leakage. Using MRI assessment, cortical disruption and the presence of an intravertrebral cleft were identified as additional strong risk factors regarding cortical (intradiscal) cement leakage, thereby potentiating anticipation. (C) 2011 Elsevier Inc. All rights reserved.