Jumping on the Vertebroplasty Bandwagon

With estimates for the number of current procedures now at 35,000-40,000 and growing, established spinal orthopedics companies are beginning to cash in on the rapidly growing use of bone cements and cement delivery systems for vertebral compression fracture repair, or vertebroplasty. To date, Cook Group and Medtronic Sofamor Danek have been supplying the majority of kits. Danek also recently began selling a PMMA resin tailored for vertebroplasty, and Stryker has indicated that it too has its sights set on the vertebroplasty opportunity: it is currently reformulating one of its existing cement products for use in vertebroplasty. That Stryker and Danek-- both industry leaders in orthopedics - are positioning themselves in this market suggests that it may be the next hot area in spine.

Just a few months ago, medical device industry analysts were estimating the number of current US vertebroplasties—a rapid, percutaneous technique for repairing spinal compression fractures by injecting bone cement into the vertebral body—to be around 12,000-20,000 annually. The number appears to be much higher, however—closer to 35,000-40,000, and growing. With at least 200,000 potential patients in the US alone, principally elderly, osteoporotic individuals with persistent pain that is currently treated with narcotics and immobilization, and spurred by consumer demand for an alternative, the near-term market opportunity for the sale of bone cement and delivery systems appears to be at least several hundred million dollars.

Although companies and practitioners are each angling for a piece of the action, getting a handle on the scope of the current US market has been difficult. Companies are filing for vertebroplasty-specific CE Marks in Europe, where the technique has a longer clinical history, but in the US the basic products are used off-label: No delivery systems have been cleared for injecting bone cement into the vertebral body (the labels are for cranial-maxillofacial applications or as bone biopsy and infusion systems), nor has any company filed an application for use of a bone cement in vertebroplasty.

Thus, for regulatory reasons, sellers of the needles, syringes, cements, and mixing equipment currently used in vertebroplasty are hesitant to talk on the record. Reports of several procedure-related patient deaths also have sensitized them, and have polarized practitioners into two camps, each of which has a competing economic incentive: radiologists, who imported vertebroplasty from France a decade ago, and surgeons, who came to the game later, beginning in 1996.

Radiologists argue that vertebroplasty is rightly a part of their practice because they use the best imaging modality—fluoroscopy, as opposed to a C-arm. Some surgeons, however, suggest that they are the more appropriate practitioners because they know better how to deal with life-threatening embolic complications resulting from the potential leakage of cement into the veins. (See "Vertebroplasty: Dangerous Learning Curve,"START-UP, June 2001 [A#2001900102.) Radiologists counter by pointing out that they routinely treat pulmonary emboli with filters: "They are living it day in and day out," notes one industry marketing executive. But both camps acknowledge that there's a learning curve involved: mixing cement to the appropriate viscosity and ensuring that the cement is radio-dense without thinning it too much, properly placing the needle inside the "Swiss cheese" of a vertebra to avoid veins, and rigorously controlling injection pressure.

To date, Cook Group Inc. and Medtronic Sofamor Danek , a division of Medtronic Inc. , have been supplying the majority of the kits used in vertebroplasty. Cook sells a bone access system and needle sets for vertebral body biopsy and infusion—as a maker of catheters and needles, the radiology market is a natural for it. In May 2000, Danek became the exclusive worldwide distributor for Parallax Medical Inc. , whose founders include radiologists Jacques Dion, MD, of Emory University , who introduced vertebroplasty in the US, and Mary E. Jensen, MD, of the University of Virginia , who performed the first US vertebroplasty. Parallax's CDS cement delivery system is indicated in the US for the injection of bone cement into bone but not for injection into the spine. In Europe, however, where Parallax has applied for a vertebroplasty-related CE mark, Danek is expecting to launch the product imminently.

While Danek won't comment on revenues, Parallax says it expects its share of Danek's sales to reach the $3-5 million range in 2001, which translates roughly into 15,000-20,000 procedures. Cook and Danek each appear to have a little less than half the US market (in terms of number of procedures), with the balance going to the American OsteoMedix (AOM) division of Interpore Cross International Inc.AOM, which merged with Interpore earlier this year [See Deal], introduced its controlled delivery system, the AOM-CDO, in mid-2000; Interpore management has said AOM-CDO sales could approach $3 million in 2001, growing to $10-13 million in 2002. Danek and Cook are pricing their products in the $300-600 range per procedure, exclusive of the cost of cement; AOM is slightly higher because its system is designed to repair several vertebral levels simultaneously.

Even more so than developers of cement delivery systems, however, because of potential toxicity concerns, makers of bone cement have been extremely careful not to link their products directly to vertebroplasty. Nonetheless, in addition to CDS, Danek recently began to sell a PMMA resin, 510(k)-cleared for cranioplasty, that Parallax supplies via its contract manufacturer, Tecres SPA . Trademarked by Parallax as Secour, it is a lower-viscosity PMMA than Tecres' Cemexor competitive PMMA ceramics such as Stryker Corp. 's Simplex. Secour also incorporates different-sized ceramic particles to improve visualization.

Stryker has recently indicated that it too has its sights set on the vertebroplasty opportunity. "We've noted the use of Simplexfor these applications," explains Jim Poser, VP and GM, bone substitutes, at the company's Howmedica Osteonics Corp. division. The flow characteristics of Simplex, which is designed for total joint replacements, not injection into the spine, are not optimal for vertebroplasty, however: it's too doughy to be delivered easily using a syringe and to give good penetration within the vertebral body. But Howmedica is also the exclusive US and European licensee for BoneSource, Orthofix International NV 's US division Orthofix Inc. 's resorbable, radio-dense calcium phosphate cement [See Deal], which is cleared in the US for use in cranial-maxillofacial procedures, but not for general orthopedic use, and is currently formulated as a suspension. According to Poser, Stryker is modifying the compound to improve its flow characteristics and will likely file an IDE to expand its label.

"We have some proprietary position in vertebroplasty," he notes. "It represents the single most attractive opportunity for Bonesourceoutside of cranial-facial." Stryker also sees opportunities in vertebroplasty for the introduction of optimized cement delivery systems including syringes, mixing apparatus, and needles for open or closed access.

More broadly, that Stryker and Danek—both industry leaders in orthopedics–are positioning themselves in the market suggests that vertebroplasty may be the next hot area in spine.