LOUISVILLE, Ky. (AP) - Donna Paul was riding a bike on vacation last spring when she lost control, instinctively flinging out her hand as she crashed to the ground.
The longtime nurse didn’t need an X-ray to see that her injury was serious. One bone had ripped through the skin and images taken later showed jagged pieces of bone splayed in a circle at the base of her hand, what’s called a distal radius fracture.
“She really must have gone down hard,” said Amitava Gupta, the hand surgeon whom Paul contacted after she and her husband cut short their Hilton Head getaway to return home to Louisville.
Unbeknownst to Paul, her bad break became the perfect candidate for a new bone graft product created by Vivorte, a Louisville biomedical startup.
For decades, the medical community has struggled to find a way to help the body repair itself after cancers eat holes in legs, car accidents and falls from ladders smash heels and knee caps, and bike accidents like Paul’s leave a surgeon with the task of pulling fragments together to ensure the bone repairs itself properly.
Pins, screws and plates have been key along with products that the biomedical industry has experimented with for years to aid regrowth of natural bone. Orthopedic surgeons often have used a synthetic material to fill the voids left by fractures.
Bones, unlike most tissue in the body, can completely regenerate but the cells can’t cross spaces without a structure to attach to, said Michael Voor, company co-founder and associate professor of orthopedic surgery and bioengineering at the University of Louisville.
So physicians have used wedges, granules and cement fillers to plug big and small spaces since the body eventually will absorb the substance and remodel itself back into bone. Often it takes years before real bone is entirely incorporated - and in the interim, the fix can weaken a limb or joint. If it’s too rigid, it poses a risk for a new fracture, he said.
In the past, before cadaver bone pieces were used, doctors sliced into other parts of a patient’s body to take bone to grind up and feed into the wound area. That forced a patient to recover from two surgeries, said Gupta, of Norton Healthcare.
Doctors and biomedical researchers like Voor have documented that the body’s bone cells regenerate more quickly if they can attach to real bone particles. Voor and Robert Burden Jr., Vivorte ’s director of engineering, created their bone repair kits with tiny bow-tie shaped bone pieces, or trabs that they found link to each other better and accelerate the conversion to natural bone.
The closest competitor, EquivaBone, mixes cement with powdered bone. But it requires triple the amount of bone particles compared with Vivorte’s Trabexus kits and also has shown problems with weakness, said Voor, who is 50. “That’s really the secret sauce with our product. We’ve sped up the remodeling process.”
More than a dozen surgeons scattered across the U.S. have used the products in about 150 procedures since it was cleared for use by the federal Food and Drug Administration in spring 2015.
Doctors mix a hardening compound, powdered calcium phosphate and tiny 2.5-millimeter trabs to create a flowable cement that looks similar to white spackling. It’s fed into a syringe and squeezed immediately into the bone break area during surgery. Because the substance hardens within seven minutes or so, time is of the essence.
In Paul’s case, the putty was squeezed around plates and screws that Gupta affixed to pull together her wrist fragments.
Instead of using a bone powder, as he once did, the company’s putty flowed into the void. “I like how easy it is to work with,” Gupta said one afternoon after a day of surgeries. Also, “it absorbs better,” as he confirmed by reviewing X-rays of Paul’s healing in the months afterward.
Voor, who attended St. Xavier before moving with his family to Florida, earned undergraduate and graduate degrees at Tulane University. He founded a bioengineering lab at U of L’s School of Medicine. He’s linked to six patents, including a device to prevent hip fractures and two others to improve the “halo” vest which doctors use to immobilize patients’ heads after serious neck and spinal cord injuries.
At the urging of his sister Ruth, a former executive with medical manufacturer Johnson & Johnson, the pair launched Vivorte in 2009 in hopes of developing and commercializing other devices by Michael Voor and colleagues. Ruth Voor, 56, a graduate of Mercy Academy and the U.S. Naval Academy, is the chief executive and oversees day-to-day operations.
The company has received about $6.4 million in grants, venture capital and investments from family, friends and several private investors here and in Boston. After the Trabexus products were rolled out in early 2015, sales reached $250,000 and grew to $450,000 by the end of last year, Ruth Voor said.
Now under development at the offices and a lab at 1044 E. Chestnut St. near downtown Louisville is another variation doctors have asked for - a bone putty with even tinier cadaver bone particles to squeeze through a hypodermic needle for reaching into knees, hips, shoulder joints and the tiny bone voids of cancer patients.
“I’m very excited about the potential,” Michael Voor said. If they can get the product into a more injectable form, “that has a tremendous amount of upside.”
Rob Keynton, a professor of bioengineering, expects someday a large orthopedic company could acquire Vivorte because the bone graft material is a significant improvement over what’s now available. He’s tracked the Voors’ progress and also became acquainted with Ruth Voor while serving with her on an oversight committee on a research partnership between U of L and the Wallace H. Coulter Foundation.
Her background in product development and working with FDA protocols was a good fit for the company, Keynton said.
Paul, who broke her wrist, was unaware of the backstory on her surgery. The 63-year-old got through it fine and started hand therapy shortly thereafter. She was surprised to regain mobility so well, bending, flexing and twisting her hand within weeks - movement that she worried she’d never regain.
She’s just glad she put herself in Gupta’s care. “I was just really pleased.”
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Information from: The Courier-Journal, https://www.courier-journal.com
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