Comparison of Balloon Kyphoplasty with the New Kiva® VCF System for the Treatment of Vertebral Compression Fractures

Background: Vertebral compression fractures are common among the elderly, which is conditionedby osteoporosis. They cause back pain and limit the patient’s activities. The Kiva® VCF TreatmentSystem is a new device to treat vertebral compression fractures. Compared to other methods, theutilization of the Kiva System reduces the risk for complications and delivers improvements in backpain reduction and functionality.Objectives: Evaluation of safety and effectiveness of the Kiva System in comparison to balloonkyphoplasty on the basis of matched pairs.Methods: 52 patients (47 - 89 years, 68 fractures) were treated with balloon kyphoplasty or withthe new Kiva System. Back pain and impairment of motility were assessed preoperatively and 6months postoperatively, with the Visual Analog Scale (VAS) and Oswestry Disability Index (ODI). Theoperation time and cement extravasation were recorded. Control radiographs were evaluated fornew fractures and vertebral heights.Results: Mean VAS values in both groups improved from preoperatively 87.6 ± 12.8 and 83.1 ± 14.9to 10.8 ± 20.8 and 24.6 ± 11.0 6 months after the treatment. The improvement after 6 months in theKiva group was significantly better than in the balloon kyphoplasty group (P < 0.0001). Mean ODI scoresin both groups also improved from 68.7% ± 15.8% in the Kiva group and 80.6% ± 8.6% in the balloonkyphoplasty group preoperatively to 24.8 ± 18.6% and 33.2 ± 6.3% 6 months after treatment. The meanoperation time for the Kiva group was 12.7 ± 3.7 minutes per vertebra and cement leakage occurred in 6patients. The mean operation time for the balloon kyphoplasty group was 34.1 ± 7.0 minutes per vertebraand cement leakage occurred in 8 patients. Anterior and mid vertebral height in the Kiva group increasedfrom preoperatively 21.06 ± 7.44 mm and 18.36 ± 5.64 mm to postoperatively 22.41 ± 7.14 mm and20.41 ± 6.00 mm. Anterior and mid vertebral height in the balloon kyphoplasty group increased frompreoperatively 21.68 ± 2.06 mm and 21.97 ± 1.78 mm to postoperatively 25.09 ± 2.54 mm and 25.29 ±2.10 mm. Vertebral height restoration could be therefore maintained with both procedures for 6 months.In the Kiva group 2 cases of nonadjacent fractures and one case of adjacent fractures were observed.In the balloon kyphoplasty group 9 cases of adjacent, as well as 5 cases of nonadjacent, fractures wereobserved. In the Kiva group significant fewer fractures occurred.Limitations: The study includes only 26 patients for each procedure, which were compared on thebasis of matched pairs.Conclusion: The Kiva System appears to be a safe and effective procedure for the treatment ofvertebral compression fractures. Six months after treatment with the Kiva System, better VAS valuesthan the values after the treatment with balloon kyphoplasty were recorded. Reduction in functionalimpairment was as successful as it was after balloon kyphoplasty. Vertebral height restoration wasobserved in both groups, which was sustained for 6 months. The risk of cement extravasationduring the Kiva Treatment is nearly the same as in balloon kyphoplasty; however, it requires a shorteroperation time and produces fewer new fractures.Key words: Vertebral compression fracture, Kiva, kyphoplasty, vertebral augmentation,osteoporosis, back pain