Impact of Cement Distribution on the Efficacy of Percutaneous Vertebral Augmentation for Osteoporotic Fractures: Assessment with an MRI-Based Reference Marker.

Abstract

Background: No studies have evaluated the impact of the cement distribution as classified on the basis of the fracture bone marrow edema area (FBMEA) in magnetic resonance imaging (MRI) on the efficacy of percutaneous vertebral augmentation (PVA) for acute osteoporotic vertebral fractures.

Methods: The clinical data of patients with acute, painful, single-level thoracolumbar osteoporotic fractures were retrospectively analyzed. The bone cement distribution on the postoperative radiograph was divided into 4 types according to the distribution of the FBMEA on the preoperative MRI. The primary outcomes were the postoperative visual analog scale (VAS) for pain and Oswestry Disability Index (ODI) scores. Cement leakage, adjacent vertebral fractures (an important concern in complications after vertebroplasty and a subset of new fractures), and recollapse of the treated vertebra were also evaluated.

Results: A total of 128 patients, 80.5% of whom were female, were included and had follow-up for 24 months. The mean patient age (and standard deviation) was 74.2 ± 8.6 years. The cement distribution was classified as Type I in 18 patients, Type II in 26, Type III in 46, and Type IV in 38. At the primary time point (6 months), there was a significant difference in the ODI score favoring the Type-III and Type-IV groups compared with the Type-I and Type-II groups (adjusted 95% confidence interval [CI]: Type I versus Type II, -2.40 to 4.50; Type I versus Type III, 1.35 to 7.63; Type I versus Type IV, 1.27 to 7.92; Type II versus Type III, 0.67 to 6.21; Type II versus Type IV, 0.63 to 6.46; adjusted p < 0.0083), whereas no significant differences were found between the 4 groups in the VAS pain score. The Type-II and Type-IV groups had a higher incidence of cement leakage, and the Type-III and Type-IV groups had a lower incidence of vertebral recollapse.

Conclusions: An adequate distribution of bone cement is advantageous for functional improvement, short-term pain relief, and a lower rate of vertebral recollapse. The FBMEA appears to be a feasible reference marker for evaluating the performance of the PVA procedure.

Level of evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.