Compression fractures affect many individuals worldwide. An estimated 1.5 million vertebral compression fractures occur every year in the US. They are common in elderly populations, and 25% of postmenopausal women are affected by a compression fracture during their lifetime. Although these fractures rarely require hospital admission, they have the potential to cause significant disability and morbidity, often causing incapacitating back pain for many months. This review provides information on the pathogenesis and pathophysiology of compression fractures, as well as clinical manifestations and treatment options. Among the available treatment options, kyphoplasty and percutaneous vertebroplasty are two minimally invasive techniques to alleviate pain and correct the sagittal imbalance of the spine.
Vertebral compression fractures (VCFs) of the thoracolumbar spine are common in the elderly, with approximately 1.5 million VCFs annually in the general US population.1 Approximately 25% of all postmenopausal women in the US get a compression fracture during their lifetime.2 The prevalence of this condition increases with age, reaching 40% by age 80.3 Population studies have shown that the annual incidence of VCFs is 10.7 per 1000 women and 5.7 per 1000 men.4 Men older than age 65 years are also at increased risk of compression fractures. However, their risk is markedly less than that of women of the same age.4–6 Vertebral compression fractures are as common in Asian women as in Caucasian women, and less common in African-American women.
Most vertebral compression fractures are a consequence of osteoporosis, are asymptomatic or minimally symptomatic, and occur with no or minimal trauma.
Vertebral osteoporotic compression fractures (see Osteoporosis) are common in the thoracic spine (usually below T6) and lumbar spine, particularly near the T12-L1 junction. There may be no preceding trauma or only minimal trauma (eg, a minor fall, sudden bending, lifting, coughing). Patients who have had an osteoporotic vertebral fracture are at higher risk of other vertebral and nonvertebral fractures.
Occasionally, compression or other vertebral fractures result from significant force (eg, a motor vehicle crash, a fall from a height, a gunshot wound). In such cases, the spinal cord is often also injured (see Spinal Trauma), and the spine may be fractured in > 1 place. If the cause was a fall or jump from a height, one or both heels may also be fractured (see Calcaneal Fractures); 10% of all patients with a calcaneal fracture also have a thoracolumbar fracture (because of the axial load to the skeleton when landing on the heels).
Symptoms and Signs
Osteoporotic vertebral fractures are asymptomatic or cause only loss of height or kyphosis in about two thirds of patients. In other patients, pain may develop immediately or later. The pain may radiate into the abdomen. Radicular pain, weakness, and reflex or sphincter abnormalities are uncommon. The pain typically decreases after about 4 wk and resolves after about 12 wk.
Although less severe than hip fractures, VCFs can cause severe physical limitations. Chronic back pain, which is associated with these kinds of fractures, leads to functional limitations and significant disability. Multiple adjacent VCFs can lead to progressive kyphosis of the thoracic spine, resulting in a number of comorbidities, such as decreased appetite resulting in poor nutrition and decreased pulmonary function.5,7,8 The progressive decline in health status likely contributes to increased morbidity and mortality in patients with VCF compared to the general population.8,9 VCFs also significantly increase medical costs
The Kiva® VCF Treatment System provides a new implant-based approach to vertebral augmentation in the treatment of painful VCFs. It is indicated for use in the reduction and treatment of spinal fractures in the thoracic and/or lumbar spine from T6-L5. It is intended to be used in combination with the Benvenue Medical Vertebral Augmentation Cement Kit.
Kiva is a unipedicular, PEEK-OPTIMA implant, solution for vertebral augmentation and a departure from balloon kyphoplasty making it the first new approach to the treatment of vertebral compression fractures in over a decade. Kiva has been demonstrated to meet or exceed the performance of balloon kyphoplasty (BKP) in three separate comparative studies. In one or more of these studies, as compared to BKP, Kiva was shown to:
- Reduce rate of adjacent level fracture
- Improve kyphotic angle restoration
- Reduce rate of cement extravasation
- Reduce the cement volume
The Kiva VCF System features a deployment device that allows the treating physician to seamlessly deliver the implant to the patient through one small incision. Unlike with balloon kyphoplasty systems, this device does not require a bi-pedicular approach and it does not require the treating physician to deflate a balloon in order to fill the vertebral body with cement. In clinical studies, the Kiva System was shown to meet or exceed the performance of balloon kyphoplasty in subsequent fracture rates, cement extravasation (leakage) rates and pain/function scores.
Cylindrical Implant Design
- Stabilizes fracture with less amount of bone cement
- Implant design acts as cement restrictor
- Implant directs cement flow centrally
- Physician customizes the amount of implant delivered into fracture
PEEK-OPTIMA Implant Material
- More similar to cortical bone than PMMA
- Even with PMMA, 50% less stiff than PMMA alone
Nitinol Kiva Coil
- Pre-shaped Nitinol wire retains its stacked coil configuration
- Creates a track within the cancellous bone for implant deployment
- Radiopaque and highly visible under fluoro
MIS, Unilateral Approach
- Kiva is delivered through a transpedicular approach
The Kiva® VCF Treatment System by Benvenue Medical, Inc. received 510(k) clearance from the U.S. Food and Drug Administration (FDA) for the reduction and treatment of spinal fractures. The Kiva System is a novel implant-based solution for vertebral augmentation and a departure from balloon kyphoplasty (BKP), making it the first new approach to the treatment of vertebral compression fractures (VCFs) in over a decade. In the clinical studies provided in support of the 510(k) application for market clearance, the Kiva System was shown to meet or exceed the performance of BKP, the current standard of care in treating VCFs.
“Physicians and patients both benefit by having Kiva as a new,minimally invasive treatment option for painful VCFs. I’m excited to have been a part of KAST, an FDA-approved pivotal trial of the Kiva System, and I look forward to presenting the results at the Society for Interventional Radiology meeting in March,” said Sean M. Tutton, MD, FSIR, Co-Principal Investigator in the KAST Study (Kiva System as a Vertebral Augmentation Treatment – A Safety and Effectiveness Trial) and Professor of Radiology and Surgery at the Medical College of Wisconsin in Milwaukee. KAST compared Kiva to the Medtronic KyphX® System for balloon kyphoplasty.
VCFs occur when a vertebra (bone in the spine) cracks, fractures or collapses. Over the last 10 years, the approaches to treating VCFs have included conservative therapies or vertebral augmentation, traditionally performed with balloon kyphoplasty or vertebroplasty. The Kiva System features a proprietary, cylindrical implant made from PEEK-OPTIMA®, representing a new approach to vertebral augmentation. The traditional approaches rely solely on a bolus of bone cement.
“We are excited to bring the Kiva System and its clinical benefits to the large and growing population of VCF patients in the US market,” said Robert K. Weigle, CEO of Benvenue Medical, Inc. “The VCF segment has little Level I clinical data, and we are proud to have sponsored one of the largest randomized studies in this space to date.”
VCFs are most often caused by osteoporosis, and there are 700,000 osteoporosis-related vertebral compression fractures annually in the U.S. alone, representing a large patient population which is only expected to continue growing as the population ages. Other causes of VCFs include trauma and malignant bone tumors that cause the spine to collapse.
About the Kiva VCF Treatment System
The Kiva VCF Treatment System provides a new, implant-based approach to vertebral augmentation in the treatment of painful VCFs. It is indicated for use in the reduction and treatment of spinal fractures in the thoracic and/or lumbar spine from T6-L5. It is intended to be used in combination with the Benvenue Vertebral Augmentation Cement Kit.
The Kiva System features a proprietary flexible implant made from PEEK-OPTIMA®, a biocompatible polymer that is widely used and well accepted as a spinal implant. The Kiva implant is designed to provide structural support to the vertebral body and a reservoir to direct and contain bone cement during vertebral augmentation. The implant is delivered percutaneously over a removable guidewire in a continuous loop into the vertebral body through a small diameter, single incision. The amount of the Kiva implant delivered is physician-customized during the procedure.
The Kiva System received CE Mark in 2008 and it is distributed by Zimmer Spine in Europe.
About Benvenue Medical, Inc.
Founded in 2004, Benvenue Medical, Inc. develops next-generation, minimally invasive expandable implants for the spine. The company is privately held and funded by Versant Ventures, DeNovo Ventures, Domain Associates and Technology Partners. Its first products are designed for the treatment of vertebral compression fractures and degenerative disc disease, which have combined revenues of $1.6 billion globally.