A new study has found that nitinol endovertebral prosthesis assisted vertebroplasty is safe and effective in achieving and maintaining pain relief and height restoration in over one year of follow-up for patients with painful vertebral collapses.
Giovanni Anselmetti, Interventional Radiology, Institute for Cancer Research and Treatment, Candiolo, Turin, Italy, presented the results of the study at the Society of Interventional Radiology’s 36th Annual Scientific Meeting in Chicago, USA.
The investigators set out to assess the safety, effectiveness and vertebral height restoration, device migration and new fracture occurrence after vertebroplasty with a novel device during long-term follow-up (11 to 19 months, mean=14.9±2.0 months). He told delegates that from December 2009, 40 consecutive patients (36 female, mean age 76±6 years) were treated for 42 painful vertebral collapses (39 osteoporotic and one myeloma) by nitinol endovertebral prosthesis (Spinealign Medical’s Vertelift) assisted vertebroplasty. Two patients were treated on two contiguous collapsed levels.
In all patients, pain was evaluated with Visual Analog Scale (VAS), quality of life with Oswestry Disability Index (ODI) before the procedure, 48 hours after the procedure and prospectively during follow-up. The treated vertebrae were measured with multiplanar reconstruction CT before the procedure, immediately after and at the end of follow-up. Prospective evaluation and measurements were performed by two independent interventional radiologists who were blinded to clinical outcomes. Anselmetti said that 84 Vertelift nitinol cages were used and that the cages are completely retrievable until the injection of bone cement.
Results
Anselmetti explained that the procedure was completed in all patients without complications, but that two patients were lost to follow-up. “At the endpoint one patient underwent surgical fixation because of incomplete relief from back pain and one other died after six months for heart failure,” he said.
Visual analog scale significantly improved in 38 of 40 patients from an average of 8.0±1.6 pre-operatively to 1.1±1.7, post-operatively (p<0.0001, Wilcoxon test). Similarly, Oswestry disability questionnaire significantly improved from 69.7±16.0% to 6.5±13.7% (p<0.0001, Wilcoxon test)
He also noted that vertebral height (millimetres) was significantly increased in 38 out of 40 patients. The average height restoration in the coronal plane using Dunn’s Multiple comparison test on the left was 19.6 preoperatively, 22.0 postoperatively and 21.3 at one year. Similarly, in the middle, the height of the disc was 13.2 preoperatively, 17.1 postoperatively and 17.0 at one year. On the right, the height was 19.0 preoperatively, 20.6 postoperatively and 21.0 at one year. (Preoperatively vs. one year, p<0.001 in all measures)
The average height restoration in the sagittal plane on the anterior using Dunn’s Multiple comparison test was 17.2 preoperatively, 19.5 postoperatively and 19.2 at one year. In the same plane, in the centre, height of the disc was 12.2 preoperatively, 16.9 postoperatively and 16.4 at one year. Posteriorly, height was 21.7 preoperatively, 23.7 postoperatively, and 23.3 at one year. (Preoperatively vs. one year, p<0.001 in all measures)
“There were no major complications, and no symptomatic cement leakages. Six of the 42 vertebrae treated (14.3%) has mild asymptomatic leakage, of which five were discal and one was parapedicular. There was no implant migration at long-term follow-up. Four patients (11.7%) in the study had a new vertebral fracture (all in the adjacent vertebra) during follow-up. No device migration was noted,” said Anselmetti.
