Fixing jaws: Polyester, polymer ties deliver unique design

Fixating the jaw with wire and screw-based systems for fracture repair and corrective jaw techniques has long been used yet causes patient discomfort, and wire sticks can expose surgeons to blood-born infections. An alternative device could transform this invasive process.

Minne Ties, developed during Altru Health Systems’ head and neck surgeon Dr. Alan Johnson’s involvement with the University of Minnesota’s Medical Device Center Innovation program, is a non-invasive jaw-fixation device that eliminates sharp wires, bone screws, and arch bars to achieve maxilla-mandibular fixation (MMF).

“I detested the long, clumsy process of wiring a person’s jaw, but despised the process of taking them off of patients in the clinic even more,” Dr. Johnson says. “Patients suffer, and I felt responsible for not having a better solution.”

The zip tie-like mechanism – one end a smooth clasp head, the other a blunt tip introducer – is packaged sterile to allow for quick procedures in surgical and non-surgical settings. It provides a steady force and secure bite to allow for closed reduction fracture management or stabilization for internal fixation.

PHOTO COURTESY OF MINNE TIES/SUMMIT MEDICAL 

“I envisioned a polymer material, similar to a nylon suture or a polymer/plastic zip tie,” Johnson explains. “The original prototypes that I placed in my mouth were made of a braided suture. I would thicken the braided structure by placing a monofilament (flexible plastic rod) down the middle of the braided structure.”

Johnson made about a dozen early prototypes from scrap sutures, medical devices, and raw materials. During the process, he worked closely with co-inventors Laura-Lee Brown and Christopher Rolfes, both MDC fellows, and Samuel Levine, M.D., professor in the Department of Otolaryngology, Head and Neck Surgery. Once he honed-in on a design – including a blunt needle insertion end that would be handled with a needle driver (the clamp that surgeons use to suture) – Johnson completed design-build test cycles, including a fifth cycle on his own teeth.

However, Johnson still needed a distinct design for the clasp mechanism.

So in 2014 medical device manufacturer, Summit Medical, licensed the technology for further development through the university’s Office for Technology Commercialization.

“I was in the process of looking at technologies that were available to license to diversify our business in areas to grow and where we had synergies but allowed us to differentiate ourselves,” says Summit Medical President Kevin Mclntosh. “And this was unique as it crossed into multiple different specialties – ear, nose, and throat (ENT), oral maxillofacial (OM) surgeons, plastic surgery. We already had an ENT and plastic surgery space franchise so with two thirds of the market spaces checked, we could leverage and grow our customer base by jumping into the OM space and entering a market we weren’t in.”

The next step for Summit Medical was to take the design to a fully-commercializable, manufacturable device. Design challenges they had to meet included the strength of the construct; the locking mechanisms; and ease of use for the end customer.

“We were able to define what the primary ligature was made out of and how; and most importantly the design of the locking mechanism to make sure it worked properly every time,” McIntosh says.

The polyester braided suture material was modified with a polymer coating that could aid in the locking mechanism, comfort, and ease of use. Summit Medical’s blunt introducer – a stainless-steel introducer that guides between teeth and locking mechanism and clasp (clasp-pad) mechanism – provided the locking feature.

Minne Ties achieved Food and Drug Administration (FDA) 510(k) clearance in 2017. Since then, they have been used in academic hospitals and trauma centers across the country. The product has been shown to reduce application time from almost 1 hour to about 12 minutes.

Minne Ties

Summit Medical