Abstract
Refracture of cemented vertebrae is often seen after percutaneous vertebroplasty. The purpose of this prospective study was to evaluate pre-procedural magnetic resonance images (MRI) for the prediction of further collapse and vertebral height loss after vertebroplasty. This study included 81 consecutive patients (73 women and 8 men) with osteoporotic compression fractures. MR studies were performed 1-5 days before vertebroplasty. Patients were followed to evaluate refracture for a minimum of 6 months after treatment. Cox proportional hazards model was used to evaluate relationships between clinical data, covariates on pre-procedural MRI, and the presence of cemented vertebrae refracture. The mean refracture rate was estimated with the Kaplan-Meier method. After a mean follow-up of 23.0 ± 8.2 months, 46 cemented vertebrae (57%) experienced refracture, and the mean loss of anterior vertebral height was 11.3%. The 1-year refracture rate after vertebroplasty was 7%, and rapid increased to 76% in the third year. Cox proportional analysis showed that any 1% decrease in signal intensity on T2-weighted images of the injured vertebra will increase the refracture rate by 0.74% (OR = 0.26, 95% CI 0.08-0.81, p = 0.02), and a 1% increase in the poorly enhanced volume ratio will increase the refracture rate by 4.3% (OR = 5.32, 95% CI 1.22-23.14, p = 0.03). Quantitative pre-procedural MRI appears to be useful in exploring vertebrae with poor bone marrow integrity, which effectively predicts the subsequent refracture of cemented vertebra.