Medtronic Spine LLC is sponsoring the KAVIAR study, a randomized clinical trial comparing balloon kyphoplasty to vertebroplasty for the treatment of osteoporotic vertebral body compression fractures (VCFs). Up to 1,234 subjects at up to 75 study centers with one to three VCFs and VB morphologies suitable for both balloon kyphoplasty and vertebroplasty will be randomly assigned to receive one or the other procedure. Study visits will occur at baseline, 30 days postoperatively, and at 3, 12 and 24 months postoperatively. At all visits, adverse events, back pain, back function and quality of life will be assessed. In addition, a 7-day phone call will be conducted, which will include assessment of back pain, narcotic use and adverse events. At baseline, pre-discharge, 3-, 12- and 24-month visits, lateral spine x-rays will be taken. The primary endpoint will be the proportion of patients with one or more subsequent fractures at 12 and 24 months, detected radiographically as determined by a core radiology laboratory. Secondary clinical endpoints include changes from baseline in back pain, back function and quality of life, and adverse events. Secondary radiographic comparisons include the restoration and maintenance of VB height and angulation, and sagittal vertical axis, a measure of global sagittal balance. A postoperative CT scan will be evaluated to detect cement extravasation and to examine the relationship between cement distribution and clinical outcomes. Another important feature of the study is a detailed healthcare utilization data assessment. Combined with a costing methodology based on Medicare cost data and other sources, cumulative two-year healthcare costs related to VCF will be estimated. Combined with quality of life measurements, the cost analysis will allow a calculation of the relative cost-effectiveness of balloon kyphoplasty and vertebroplasty. Sample size is based on the primary endpoint, the proportion with subsequent fractures at 12 and 24 months.
Patients with osteoporotic vertebral body compression fractures will be randomly assigned to treatment with balloon kyphoplasty or vertebroplasty. Over 2 years of follow-up, back pain, back function, quality of life, adverse events, subsequent fractures and cumulative healthcare costs will be compared.