Amedica Releases Results of Spinal Fusion Surgery Trial

Amedica Corporation’s spinal interbody spacers with porous silicon nitride center provide an equivalent fusion to PEEK (polyetheretherketone) spacers with bone autograft, a study has found.

The company reached its conclusion based on the results of its CASCADE study, a blinded, randomized clinical trial that compared outcomes of spinal fusion surgery between its composite silicon nitride spacers manufactured with a central core of cancellous structured ceramic (CsC), to the gold standard, i.e., PEEK plastic spacers filled with bone autograft.

“Surgeons have long known that autograft is the holy grail of bone healing,” said Mark P. Arts, M.D., Ph.D., a neurosurgeon at Medical Center Haaglanden, in The Hague, Netherlands. “All osteoinductive and osteoconductive formulations on the market today aspire to show healing rates that are comparable to autograft bone. Hollow-body PEEK spacers used in cervical and lumbar spinal fusion must be filled with osteoconductive materials, such as allograft, bone autograft, or synthetic biologic formulations. The CASCADE study is the first to show that a synthetic material can heal and fuse as well as the patient’s own bone. We have shown that it is no longer necessary to use hollow interbody spacers filled with bone or bone void fillers to achieve optimal fusion results.”

The CASCADE study enrolled 104 patients in a prospective clinical trial that independently scored fusion rates and clinical outcomes at 12 months follow-up. Neck Disability Index scores decreased similarly in both patient groups, consistent with clinical improvements reported in the literature. Importantly, the incidence of cervical spine fusion was statistically identical between study groups, and consistent with figures reported in other studies.

“The significance of the CASCADE data cannot be overstated,” said Sonny Bal, M.D., chairman/CEO of Amedica. “For the first time, a porous synthetic interbody spacer with no bone or bone fillers has shown fusion rates that are equivalent to the gold standard. Previously we have demonstrated that the surface topography and chemistry of our current Valeo silicon nitride spacers are conducive to bone ongrowth and bacterial resistance. In fact, many manufacturers are trying to overcome the limitations of PEEK spacers by enhancing PEEK with costly porous metal coatings, or hydroxyapatite and related materials.”

Amedica currently is preparing a scientific paper describing the CASCADE study for publication in a peer-reviewed journal. The company also is preparing a 510(k) application for the U.S. Food and Drug Administration based on the final clinical data.

“In addition to the bone ongrowth, strength, biocompatibility, favorable radiographic imaging and antibacterial properties of silicon nitride, we have now shown that the cancellous formulation of our material enables bone ingrowth and spinal fusion by itself, i.e., without relying on additives,” Bal added. “We expect this advantage will translate into decreased cost and complexity of surgical procedures.”

The CsC product used in the CASCADE study is approved for use in Europe.

Based in Salt Lake City, Utah, Amedica is a biomaterial company that develops and commercializes silicon nitride ceramics. The firm also is developing wear- and corrosion-resistant implant components for hip and knee arthroplasty.