KAVIAR Study - Kyphoplasty And Vertebroplasty In the Augmentation and Restoration of Vertebral Body Compression Fractures

A Multicenter, Randomized, Prospective Clinical Trial to Compare the Short- and Long-term Safety and Effectiveness of Balloon Kyphoplasty to Vertebroplasty in the Treatment of Painful, Acute Osteoporosis-related Vertebral Body Compression Fractures (VCFs).

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.

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.

Inclusion Criteria

All subjects must meet all of the following criteria to be enrolled into the study:

1. Age > 21

2. 1 to 3 target VCFs meeting the following criteria:

   1. Fracture due to diagnosed or presumed underlying primary or secondary osteoporosis
   2. All target VCFs are between T5 and L5
   3. All target VCFs to be treated show either: i. Height change: An acute (< 6 month) change in VB height or morphology from a previous x-ray, CT or MRI, with height loss at the anterior, middle or posterior portion of the VB consistent with a worsening of 1 or more grades by the Genant criteria (17), OR ii. Positive MRI or bone scan: VB shows hyperintense signal on STIR sequence MRI or target VB is positive on radionuclide bone scan
   4. All VCFs to be treated have fracture age (time from pain onset to evaluation by the Investigator) of 6 months or less
   5. Back pain correlating with the location of at least one VCF

3. Treatment of all target VCFs is technically feasible by and clinically appropriate for BOTH vertebroplasty and balloon kyphoplasty. (Team approach only: Both the vertebroplasty and balloon kyphoplasty physician have reviewed radiographic studies and agree to this prior to enrolling the subject in the study.)

4. Pre-treatment back pain by numerical rating scale (NRS) score > 4 (0-10 scale)

5. Pre-treatment Oswestry Disability Index >20 (0 - 100 scale)

6. Subject states availability for all study visits

7. Subject is able to understand the risks and benefits of participating in the study and is willing to provide written informed consent

8. Subject has mental capacity to comply with the protocol requirements for 2-year duration of study

Exclusion Criteria

Subjects who meet any of the following conditions may not be enrolled into the study:

1. VB morphology or configuration is such that either balloon kyphoplasty OR vertebroplasty is not technically feasible for the targeted VCFs

2. Fracture due to high-energy trauma

3. Suspected OR proven cancer inside index vertebral body. Note that patients with chemotherapy-related osteoporosis may be included.

4. Disabling back pain due to causes other than acute fracture (e.g., sacroiliac fracture, symptomatic degenerative disc disease, lumbar spinal stenosis)

5. Any painful VCF with fracture age > 6 months

6. Any objective evidence of neurologic compromise at baseline

7. Previous balloon kyphoplasty or vertebroplasty for any VCF

8. Spine stabilization beyond balloon kyphoplasty or vertebroplasty required for targeted VCFs

9. Significant clinical comorbidity that may potentially interfere with long-term data collection or follow-up (e.g., dementia, severe comorbid illness)

10. Pre-existing conditions contrary to either balloon kyphoplasty or vertebroplasty, such as:

    1. Irreversible coagulopathy or bleeding disorder. Note regarding reversible coagulopathies: Subjects on coumadin or other anticoagulants may participate. Investigators should follow routine practices for perioperative discontinuation and re-initiation of anticoagulants.
    2. Allergy to any device materials (e.g., bone cement) for balloon kyphoplasty or vertebroplasty. Note that in subjects with allergy to iodine-based contrast, other non-iodine contrast solutions may be used.
    3. Any evidence of VB or systemic infection

11. Pregnant or child-bearing potential