BBI Contributing Editor

NEW YORK HealthPoint (New York) hosted a one-day Spinal Industry Summit last month which featured 25 companies representing four areas: biologics, non-fusion products, minimally invasive devices and new technologies. HealthPoint projects annual growth of 25% to 30% of the spinal implants market, with a greater than tripling of revenues in the spinal implant industry in the next decade, from the current $2 billion to more than $7 billion in 2012.

The leading spine surgery procedures in 2002 were reported to be 343,000 discectomies, 320,000 spine fusions/internal stabilizations and 250,000 laminectomies. Internal stabilization techniques are expected to show rapid growth, whereas discectomies are on the decline and are being replaced by more effective conservative treatments and percutaneous surgical procedures such as ablation.

HealthPoint also forecasts an 8.3% annual rate of growth in metal implants from $1.2 billion in 2002 to $2.8 billion in 2012 and a shift from metal toward biologic products and new materials. Revenues of biologic products including allografts (structural and non-structural), surgical sealants, adhesives, anti-adhesion materials, drugs contained in implants and stem cells are expected to grow from the current $500 million to $2.3 billion during this period.

The target audience for spinal implants includes the 2,000 orthopedists who are trained as spine surgeons and the 1,200 neurosurgeons who perform spinal implant procedures. An expert panel of spine surgeons was convened to debate the relative merits of kyphoplasty vs. vertebroplasty for the treatment of pain and prevention of skeletal deformity from vertebral body compression fractures. These fractures are most commonly caused by osteoporosis. Multiple myeloma is the second-leading cause of these fractures. About 600,000 vertebral body compression fractures are reported annually, of which one-third require treatment.

Vertebroplasty is a percutaneous outpatient procedure in which bone cement (polymethylmethacrylate) is injected into the collapsed vertebra to stabilize the fracture. Kyphon (Sunnyvale, California) markets a line of inflatable bone tamps that are used to expand the vertebral space followed by the injection of bone cement in a procedure known as kyphoplasty. Vertebroplasty is a less-costly procedure than kyphoplasty, but it is considered to be less safe because of the tendency for leakage of the bone cement. Left untreated, vertebral compression fractures can lead to kyphotic deformity (spinal hump) and death from pulmonary pressure that results in respiratory failure.

Spineology (Stillwater, Minnesota) has developed OptiMesh, a minimally invasive composite bone grafting containment system for the treatment of vertebral body compression fractures and spinal stabilization. OptiMesh expands and conforms in the body, can contain any form of bone graft within the spine, controls cement flow and is capable of supporting anatomical loads. The company was founded by Stephen Kuslich, MD, a spinal surgeon who is the co-inventor of the BAK spinal fusion cage.

Tony Viscogliosi of Viscogliosi Brothers (New York), a private equity and merchant banking firm that invests exclusively in orthopedic product companies, provided an overview of treatments in this marketplace, which follows the progression of replace to repair to restore to regenerate. He characterized current advances in non-fusion spinal treatments (disc arthroplasty) as going from the replacement stage to the repair stage. Several presenters observed that current spinal fusion techniques lag behind advances in other orthopedic areas.

Artificial spinal discs

Replacement of the entire spinal disc (lumbar or cervical) or the nucleus pulposa, the gelatinous center of the disc, offers a desirable alternative to spinal fusion. These artificial discs require much less invasive surgery and are potentially a more effective treatment of chronic back pain. It is estimated that 80% of all people will experience back pain at some point in their lives. Each year, 14.3% of new patient visits to a primary care physician are for lower back pain. Six million people in the U.S. are treated annually for back pain caused by degenerative disc disease.

Disc Nucleus Replacement. Raymedica (Bloomington, Minnesota) is developing a prosthetic disc nucleus device, PDN Solo XL. It is a hydrogel that is comprised of hydrolyzed polyacrylonitrile (Hypan) and is expected to be marketed in the U.S. in 2006. The polymer is currently used as a coating in urethral stents and on guidewires, but not as an implant. After implantation, the PDN-Solo XL device begins to absorb fluid from the body and expands both vertically and horizontally. It increases the disc height and restores normal flexibility and movement, which is an improvement over spinal fusion, the currently established surgical treatment in which adjacent vertebrae are fused together. The PDN Solo XL device has the CE mark and is distributed in Europe by Medtronic Sofamor Danek (Memphis, Tennessee). It has been used on more than 750 patients outside the U.S. for treating lower back pain in patients that have not responded to conservative therapy and as an alternative to more invasive spine surgery procedures.

Replication Medical (New Brunswick, New Jersey) also is developing a disc nucleus replacement product, Aquacryl, which consists of a hydrolyzed polyacrylonitrile block copolymer that is 90% water when fully hydrated. It is implanted as a rolled up small cylinder in a dehydrated state that unrolls into a disc shape upon rehydration to restore disc height. Other companies that are developing nucleus replacement products include Disc Dynamics (Eden Prairie, Minnesota) and Spine Wave (Stratford, Connecticut), which has licensed tissue adhesive technology for spine and orthopedic applications from Protein Polymer Technologies (San Diego, California).

Entire Disc Replacement. Interpore Cross International's (Irvine, California) presentation included a review of its development of a ceramic artificial spinal disc that has a titanium base with a peg for fixation into the underlying vertebral body. Many companies also are developing artificial lumbar and cervical disc implants, but were not on the HealthPoint conference program. They include Medtronic Sofamor Danek; DePuy Acromed (Raynham, Massachusetts), a subsidiary of Johnson & Johnson (New Brunswick, New Jersey); Spine Core (Summit, New Jersey); Spine Solutions (New York); Link Spine Group (Branford, Connecticut), Axiomed Spine (Willoughby, Ohio); Scient'X in France; and Pearsalls in the UK.

Bone Grafts, Adhesion Barriers, Hemostats

Interpore Cross markets Pro Osteon resorbable, coral-derived, bone graft substitutes, a line of spine implants including cervical plates, rods and fixation devices, and Integro allograft putty and paste, which uses a proprietary phospholipid carrier. The company also is developing polymer-reinforced Pro Osteon interbody spacers.

Tutogen (West Paterson, New Jersey) is a maker and supplier of bioimplants for tissue and bone repair. Precision grafts for lumbar and cervical spine applications are supplied to Centerpulse (Zurich, Switzerland), acquired earlier this fall by Zimmer (Warsaw, Indiana). The company also supplies products that are used in urology, gynecology, ophthalmology, neurosurgery, ENT and dentistry. It maintains facilities in Florida, Germany and France.

Osteobiologics (San Antonio, Texas) is developing products for bone and cartilage repair with a primary focus on arthroscopy and sports medicine and a secondary focus on spine, trauma, wound care and general orthopedics. The company markets Polygraft, a biodegradable bone graft substitute (porous poly-glycolide infused with calcium sulfate) that can be used to deliver bioactive agents or cells. Osteobiologics has FDA clearance to market PlastFilm, a stretchable medical grade plasticized polymer film for use as an adhesion barrier in laminectomies, and IMMIX Thin Film, a semi-rigid, resorbable polymeric film that becomes pliable when inserted in warm water for use as a barrier membrane to prevent adhesions and for guided tissue regeneration, but these products are not yet being sold. Under development are IMMIX CB, a multiphase, biodegradable scaffold that provides for cartilage and bone repair after knee surgery, and resorbable polymer/ceramic composites for use as cervical and lumbar spacers. Osteobiologics is seeking corporate partners for its spinal products.

FzioMed (San Luis Obispo, California) is developing the Oxiplex line of products for use as adhesion prevention aids in surgery. Oxiplex is a bioabsorbable polymer network comprised of polyethylene oxide and carboxymethylcellulose. It can be formulated for specific medical applications as a liquid or gel, or fabricated into films and sponges with defined tissue adherence, elasticity, strength, viscosity and absorption.

Acologix (Emeryville, California), a biopharmaceutical company, is developing "osteo-renal" drugs. Its lead product, Dentonin, is a polypeptide growth factor and has demonstrated potentially superior bone formation properties to bone morphogenic protein. It has a high safety profile, as shown in a Phase 1a clinical trial. Another drug candidate, Ossamer, is a new class of small molecule that has demonstrated potent bone anabolic activity by oral administration in a postmenopausal osteoporosis model. An investigational new drug submission is planned for Ossamer in 2005.

Medafor (Minneapolis, Minnesota) featured its line of topical hemostats that employ polysaccharide microspheres and can stop active bleeding in surgical and traumatic wounds. The polysaccharide (derived from potato starch) microspheres have a porous surface that absorbs water and low molecular weight compounds from blood, concentrating platelets and clotting proteins on the bead surface and thereby enhancing endogenous clotting mechanisms.

Allografts for bone replacement

Presentations were given by the three leading suppliers of allogenic bone Musculoskeletal Transplant Foundation (MTF; Edison, New Jersey), Osteotech (Shrewsbury, New Jersey) and Regeneration Technologies (Alachua, Florida) each featuring its methods for processing cadaver bones. MTF is promoting the use of its demineralized bone as a carrier for biologics and reviewed its collaborations, which include the use of the OptiMesh device from Spineology (Stillwater, Minnesota) for fusion and vertebroplasty, a distribution agreement for porous hydroxyapatite and tricalcium phosphate with Switzerland's medArtis, a joint development with Aastrom Biosciences (Ann Arbor, Michigan), for use of MTF's allograft as a carrier for adult stem cells in orthopedic applications, and an equity investment in Vertebron (Stratford, Connecticut), a start-up company developing novel pedicle screw and cervical plate products. Regeneration Technologies featured its new products HTO, a precision wedge allograft for use in opening wedge osteotomy procedures to correct vagus and varus malalignment, and several pre-shaped allografts for anterior cruciate ligament reconstruction which include a bone-tendon-bone allograft, an achilles tendon and a quadricept tendon.

Innovative minimally invasive systems

Several companies are developing minimally invasive surgery (MIS) systems for use as an alternative to open back surgery. The anticipated benefits of MIS are reduced blood loss, less pain medication,and a shorter and less-costly hospital stay.

Mazor Surgical Technologies (Caesarea, Israel) described its SpineAssist miniaturized surgical guidance system for insertion of pedicle screws during spine fusion surgery. Mazor's robotic navigation device can provide guidance during surgical procedures where a high degree of precision is needed such as spine and brain surgery. The company's SmartAssist platform is adaptable for potential future applications in orthopedics, trauma, neurosurgery and ENT procedures.

MicroDexterity (Albuquerque, New Mexico) has developed the MicroDex system, a "force controlled" and "force sensitive" robotic manipulation system whose forces are controlled as precisely as their motions, resulting in a true dexterity enhancement. This is a key distinction between the human arm and today's industrial robots, whose motions are controlled very accurately but the applied forces are poorly controlled. When combined with advanced imaging and guidance systems, the rate of surgeon error can be dramatically decreased. Procedures that can benefit from improved human dexterity include spine, microvascular, ENT and neurosurgeries.

The company has partnered with Sandia Laboratories (Albuquerque, New Mexico) and Medtronic (Minneapolis, Minnesota) to further its development efforts and has successfully completed an Alpha prototype test. Steve Charles, MD, founder of MicroDexterity, is a prominent vitreo-retinal surgeon as well as a mechanical and electrical engineer and has successfully invented and developed ophthalmic products such as the Accurus System for vitreo-retinal surgery that is sold by Alcon Surgical (Fort Worth, Texas).

Endius (Plainville, Massachusetts) reported on its Atavi surgery system for minimally invasive spine surgery. It permits surgeons to use a visualization method of their choice, including surgical loupes, microscope or unaided direct visualization, while preserving the ability to use high-resolution endoscopy. The Atavi system enables the performance of complete posterolateral lumbar spine surgery through the same access port while maintaining significant exposure of the affected areas of the spine. It can be used for both fusion and non-fusion procedures.