Interbody spacers with silicon nitride centre provide equivalent fusion to PEEK spacers with bone autograft


Amedica has released the results of its CASCADE (Interbody fusion devices in the treatment of cervicobrachial syndrome) study, a blinded, randomised clinical trial that compared outcomes of spinal fusion surgery between its composite silicon nitride spacers manufactured with a central core of cancellous structured ceramic to PEEK spacers filled with bone autograft.

“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,” said Mark P Arts, neurosurgeon at the Medical Center Haaglanden, The Hague, Netherlands.

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.

“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,” continued Bal. “We expect this advantage will translate into decreased cost and complexity of surgical procedures, and support our efforts to receive 510(k) clearance from the FDA for the cancellous structured ceramic product used in the CASCADE study, which is already approved for use in Europe.”

Amedica is preparing a scientific paper describing the CASCADE study for publication in a peer-reviewed journal. The company will also submit an application during January 2015 in the 510(k) regulatory track based on the final clinical data. The FDA will examine all the data presented as part of a complete application for 510(k) clearance of the composite silicon nitride interbody system.