4:31 The dynamic mobility of vertebral compression fractures

Abstract

Purpose of study: Vertebral height restoration is hoped to mitigate some morbidities and adverse biomechanical consequences of osteoporotic vertebral compression fractures (VCFs) but this is unproven. Height restoration has been reported as the result of kyphoplasty [1] but is not generally thought to occur in vertebroplasty. The objective of this study is to describe the surprising frequency and substantial mobility of many osteoporotic vertebral compression fractures.Methods used: The institutional review board approved this retrospective, radiographic analysis of 41 consecutive patients with 65 VCFs who underwent vertebroplasty at a tertiary referral center. Selection criteria for vertebroplasty were pain of vertebral fracture origin, sufficient pain to impair activities of daily living, failure of reasonable medical therapy and time, comprehensive evaluation of osteoporotic, nonmalignant T5–L5 VCFs, technical feasibility, sufficient medical stability to tolerate vertebroplasty, absence of contraindication and informed written consent. Standing and supine cross-table lateral radiographs were evaluated preoperatively to assess fracture mobility and postoperatively to assess height restoration and sagittal alignment. All radiographic measurements were obtained with the use of a digitizing tablet (OrthoGraphics, SLC, Utah). Vertebral body height, area and kyphotic angle were reported as percent restoration compared with the original fracture.of findings: Mean patient age was 73.7 years. Average time from fracture to vertebroplasty was 89 days for mobile fractures and 133 days for fixed (nonmobile) fractures. Dynamic mobility was demonstrated in 44% of patients and 35% of treated vertebrae. In mobile fractures average posterior, middle and anterior vertebral height restorations were 15%, 93% and 106%, respectively. After vertebroplasty, mean vertebral body area increased nearly 30% and mean kyphotic angle decreased 40%. Intravertebral clefts, which represent vertebral cortical and cancellous discontinuity, were common in mobile fractures and were clustered at the thoracolumbar junction.Relationship between findings and existing knowledge: Vertebroplasty is a minimally invasive surgical procedure that can relieve pain of VCF. Kyphoplasty, a proprietary derivative of vertebroplasty, is the polymethlymethacrylate fixation of fractured vertebrae after purported vertebral height restoration using a percutaneous inflatable balloon tamp. Both have been shown to relieve fracture pain with an acceptable incidence of risk. We have documented that many VCFs are dynamically mobile and that recovery of lost height can be achieved with careful patient positioning alone during vertebroplasty.Overall significance of findings: This radiographic series demonstrates the surprising frequency and substantial mobility of many osteoporotic vertebral compression fractures. Fracture mobility must be considered when performing vertebral augmentation and when reporting and interpreting the significance of vertebral height restoration.Disclosures: No disclosures.Conflict of interest: No conflicts.