40 Radiofrequency Kyphoplasty: A Novel Approach to Minimally Invasive Treatment of Vertebral Compression Fractures
KEY POINTS
Introduction
Percutaneous treatment of vertebral compression fractures (VCFs) was first performed in France in 1984 by Galibert and Deramond.1 The two most commonly performed minimally invasive VCF procedures are known as vertebroplasty and kyphoplasty. The primary difference is that in kyphoplasty, commonly referred to as percutaneous vertebral augmentation, a cavity using a mechanical device is created before cement delivery.∗ Both procedures have been shown to provide dramatic pain relief in vertebral body fractures associated with underlying osteoporosis or malignancy, and have been successfully applied in cases in which conservative management has failed and surgery is undesirable.1–7, 10–14 Because they have a higher incidence of osteoporosis, most patients referred for this procedure are women. However, men with vertebral body fractures from osteoporosis also present for treatment. Many of the characteristics of the male population with osteoporotic vertebral body fractures have recently been described.4,7 Vertebral body fractures are the most common osteoporotic fractures in men. Like those in women, they are associated with significant morbidity and restriction of activities of daily living.8 The economic impact of osteoporotic fractures was estimated at nearly $2.7 billion in 1995 for men alone,9 making this a substantial health care problem from the standpoint of both cost and morbidity.
Minimally invasive treatment of vertebral compression fractures requires the image-guided insertion of a needle or working cannula through or adjacent to the pedicle into the vertebral body. Acrylic or calcium phosphate bone cement is then injected into the vertebral body (either with or without performing cavity creation) where it solidifies, providing structural support and preventing the movement associated with pain.3,14
The StabiliT Vertebral Augmentation System (DFine Inc., San Jose, CA, USA) is a novel product intended for the treatment of VCFs associated with osteoporotic fractures and tumors of the spine in a procedure known as radiofrequency (RF) kyphoplasty. RF kyphoplasty is designed to minimize leakage, enable height restoration of mobile fractures, and provide pain relief through fracture stabilization by way of site- and size-specific cavity creation and extended, controlled delivery of an ultrahigh viscosity cement. This new percutaneous vertebral augmentation system combines the following unique attributes: navigational cavity creation device; RF energy modulated, ultra-high viscosity cement; unique, hydraulic delivery system; and a remotely controlled delivery mechanism to offer additional control to the physician in treatment of a VCF. The use of RF energy to modulate bone cement polymerization immediately before entering the patient permits the system to maintain cement in a reservoir at ambient temperature with a very long working time, yet deliver cement of a viscosity many times higher than conventionally delivered polymethyl methacrylate (PMMA) cement. This control during the cement delivery results in the potential for reduced venous extravasation and yet retains the ability to move bone fragments and restore height.