Progression toward Vertebral Collapse of Vertebral Metastases Treated with Percutaneous Vertebroplasty: Rate and Risk Factors

Purpose: To evaluate of the rate of and risks for progression toward collapse in vertebral metastases (VMs) treated with percutaneous vertebroplasty (PV). Materials and Methods: A total of 151 PVs were performed in 81 patients with vertebral metastases and were retrospectively analyzed. Follow-up imaging was performed at 12 months to measure vertebral body height and to report vertebral collapse at the level of the treated vertebrae. Vertebral characteristics (spine instability neoplastic score [SINS], number of lysed cortices, and prior radiotherapy) and procedural parameters (Saliou score, cortical contact with cement, and intradiscal cement leakage) were compared between the group of patients with and without collapse of the treated vertebrae. Results: Of the vertebrae treated with PV, 41 of 151 (27%) progressed toward collapse. Vertebral collapse was influenced by a high SINS (odds ratio [OR] = 1.27, P = .004), SINS value > 9 (OR = 2.96, P = .004), intradiscal cement leakage (OR = 2.18, P = .048), pre-existing spinal deformity (OR = 2.65, P = .020), and pre-existing vertebral fracture (OR = 3.93, P = .045). A high Saliou score (OR = 0.82, P = .011), more than 3 cortices in contact with the cement (OR = 0.38, P = .014), and preserved spinal alignment (OR = 0.38, P = .020) were associated with a lower incidence of collapse. Conclusions: Rate of vertebral collapse despite PV was influenced by vertebra-specific characteristics and by cement injection quality. Vertebrae with a SINS of <= 9 and with homogeneous cement filling had a lower incidence of collapse.