A Medical Device Daily

Sometimes a small change to a product – say, using a different surface finishing technique – makes a huge difference to its overall effectiveness. That's the lesson Applied Spine Technologies (AST; New Haven, Connecticut) has learned with its Stabilimax NZ Dynamic Spine Stabilization System.

AST, a device company focused on motion preservation of the lumbar spine, said it has received permission from the FDA to proceed with enrollment in its IDE trial of the Stabilimax NZ Dynamic Spine Stabilization System. The trial resumes after AST voluntarily suspended enrollment in August 2008 following three reports of screw fracture. The company says it has collaborated with Exponent, an engineering and scientific consulting firm, and made changes to the surface finishing technique used on the screws. The result was a significant increase in the longevity under fatigue loading of the screw according to testing data.

CFO Terry Brennan told Medical Device Daily the system itself is doing great and has been all along. But in late July of last year the company saw on some of the X-rays that some pedicle screws had fractured. Brennan said the patients were unaware of the fractures and were asymptomatic at the time, but the fractures did show up on X-ray.

"We feared it might be the result of fatigue on a surface finish ... it was probably not the best surface finish to use," Brennan said.

The Stabilimax NZ system uses pedicle screws and Brennan says the difference between it and other devices on the market is that AST uses a ball and socket system and then a spring system on top of its pedicle screws. The device is designed that way, he said, to allow for near-normal physiological motion – and that is what the company hopes the IDE trial will prove.

"Voluntary suspension of enrollment late last year was the correct decision to make and management showed terrific fortitude in making that decision," said recently appointed President/CEO Craig Corrance. "AST is now eager to resume patient enrollment and we look forward to building upon the impressive results we have obtained so far."

Brennan said the company's goal is to complete enrollment within 18 months to 24 months.

"I am most pleased to commence with re-enrollment," said clinical investigator Neel Anand, MD. "The Stabilimax NZ system has the potential to address an important sector within the degenerative lumbar spine segment. Preserving motion while reducing pain, and offsetting the risk of future adjacent level symptoms, is an attractive proposition for both patient and physician."

The IDE trial is a multi-center, randomized, controlled clinical trial to compare posterior dynamic stabilization using the Stabilimax NZ system to traditional spinal fusion stabilization to treat degenerative lumbar spinal stenosis. AST has enrolled over 100 patients to date.

According to AST, the Stabilimax NZ is expected to offer numerous advantages over current spinal fixation products and even new artificial disc products – including a much less invasive and less traumatic implant procedure, maintenance of spine motion and disc function, and the potential to prevent or slow adjacent-segment disc disease.

Brennan said AST follows a "science first" philosophy and that the company does not think there are a lot of other devices on the market that are based on the physiological science.

"Our device provides more stability and more motion than any other device out there so we think it is incredibly important to get this to market because it is a new technology that will benefit thousands of thousands of patients," Brennan said. "It's definitely important to the company, but there is a true value to future patients out there."