Effect of Bone Cement Viscosity on Leakage and Outcomes in Vertebroplasty

Percutaneous vertebroplasty provides rapid pain relief in elderly patients with acute osteoporotic vertebral compression fractures; however, bone cement leakage remains a major safety concern, and the influence of cement viscosity on leakage and clinical outcomes is not fully established. This study evaluated whether high-viscosity cement reduces leakage without compromising efficacy or safety. In this single-center, prospective randomized controlled trial, 184 elderly patients with single-level acute osteoporotic vertebral compression fractures were enrolled and followed for 12 months. Traumatic burst fractures and cases with posterior wall cortical disruption causing >25% spinal canal compromise were excluded. Participants were randomized 1:1 to receive high- or low-viscosity bone cement. The primary outcome was overall cement leakage at 48 h postoperatively, assessed by computed tomography and classified using the Yeom system. Secondary outcomes included pain (Visual Analog Scale), function (Oswestry Disability Index), radiographic parameters, perioperative variables, and adverse events. High-viscosity cement significantly reduced the overall leakage rate compared with low-viscosity cement (RR 0.47, 95% CI 0.29-0.78; adjusted OR 0.36, 95% CI 0.19-0.71; P = 0.003), with consistent results in sensitivity analyses. Leakage patterns differed between groups, with C-type leakage more frequent in the high-viscosity group and B-type leakage more frequent in the low-viscosity group (P = 0.008). Pain and functional outcomes improved significantly in both groups, with no between-group differences over time (all P > 0.05). Radiographic correction, perioperative parameters, and adverse event rates were comparable. Image interpretation reliability was high (κ = 0.86; ICC > 0.90). High-viscosity bone cement reduces early leakage while maintaining comparable clinical and radiographic outcomes, supporting its use as a preferred option in vertebroplasty for this population.