Vertebral augmentation treatment of painful osteoporotic compression fractures with the Kiva VCF Treatment System

Abstract

BackgroundVertebral compression fractures (VCFs) can cause significant pain and functional impairment, and their cumulative effect can lead to progressive morbidity. This single-arm, prospective feasibility trial, conducted at 4 clinical sites, was undertaken to evaluate the clinical outcomes associated with the use of an innovative vertebral augmentation device, the Kiva VCF Treatment System (Benvenue Medical, Santa Clara, California), in the management of symptomatic VCFs associated with osteoporosis.MethodsVertebral augmentation treatment was performed for persistent back pain symptoms in 57 patients (mean age, 71.9 ± 10.4 years), including 46 women, with radiologically confirmed VCFs; 36 of these patients (63%) had reached 12 months of follow-up at this data analysis. There were 51 one-level cases, 5 two-level cases, and 1 three-level case, representing 64 treated levels. Back pain severity and condition-specific functional impairment were evaluated with a standard 100-mm visual analog scale and the Oswestry Disability Index (ODI), respectively, before device implantation as well as at 6 weeks, 3 months, and 12 months.ResultsMarked clinical improvements were realized in back pain severity and functional impairment through 12 months of follow-up. The mean back pain score on the visual analog scale improved from 79.3 ± 17.2 before treatment to 21.9 ± 21.3, 21.9 ± 24.6, and 23.2 ± 23.3 at 6 weeks, 3 months, and 12 months, respectively. The mean decrease at 12 months was 49.9 ± 30.3 mm, or approximately 66% (P < .0001). Similarly, the mean ODI score improved from 68.1% ± 16.9% before treatment to 27.4% ± 17.2%, 23.8% ± 18.7%, and 23.3% ± 15.5% at 6 weeks, 3 months, and 12 months, respectively, representing a mean change of 39.2 ± 19.6 percentage points, or approximately 63%, at 12 months. Overall clinical success rates based on a 30% improvement in pain severity or greater and maintenance or improvement in the ODI were 91%, 88%, and 89% at 6 weeks, 3 months, and 12 months, respectively. The vertebral augmentation procedure required injection of a mean of 2.2 ± 0.12 mL of cement per vertebral body. There were 5 levels (8%) where cement extravasation was identified radiographically, and none were related to clinical symptoms.ConclusionsThese pilot findings are encouraging, suggesting robust and durable clinical improvement after this novel vertebral augmentation procedure in patients with painful VCFs.

Advances in Vertebral Augmentation Systems for Osteoporotic Vertebral Compression Fractures

“…The Kiva System was applied to patients with painful A1.1, A1.2, or A1.3 (AO spine fracture classification) OVCFs at the thoracic and lumbar spine or at an age at entry of 50 years or greater; 1–3 symptomatic OVCFs were considered [ 53 ]. Furthermore, a VAS score of 5 or greater, fracture age of less than 6 months, and an ODI score of 30% or greater were required [ 10 ].…”

“…A study on the Kiva System showed that the mean back pain score on the VAS decreased by approximately 66% ( P < 0.0001), and the improvement of the mean ODI score was approximately 63% at 12 months after operation. In addition, approximately 8% of cement extravasation was identified radiographically; however, no clinical symptoms were observed [ 10 ].…”

“…A comparison of the PKP and the Kiva System for OVCFs at 6 months after surgery indicated that the improvement in VAS in the Kiva group was significantly better than that in the PKP group ( P < 0.0001), and the mean ODI scores in both groups also improved from 68.7% ± 15.8% to 24.8 ± 18.6% in the Kiva group and from 80.6% ± 8.6% to 33.2 ± 6.3% in the PKP group 6 months later. Furthermore, the mean operation time in the Kiva group was shorter than that in the PKP group, in which 12.7 ± 3.7 minutes per vertebra was observed in the Kiva System group and 34.1 ± 7.0 minutes per vertebra was observed in the PKP group [ 10 ].…”

“…The Kiva System can be effective for painful vertebral fractures [ 2 , 10 , 53 , 55 ]. Longer observation, however, is needed to confirm whether the Kiva System provides positive functional improvement, and further randomized prospective studies with larger patient samples are necessary to predict long-term outcomes after the intervention [ 53 , 56 ].…”

“… A percutaneous nitinol coil guidewire (a) is coiled within the cancellous portion of the fractured vertebral body. (b) Afterwards, a radiopaque PEEK implant is delivered incrementally via the nitinol coil guidewire (c) and then a nesting, cylindrical column is formed that provides vertical displacement, which may restore the height of the fractured vertebra (d) [ 10 ]. Fluoroscopic images illustrating the procedure of using the Kiva VCF treatment system (e).…”