Inventor has interesting story

Jan. 27—GREENSBURG — Mark Rethlake is applying for a patent for something you've probably never heard of, and (hopefully) will never need.

Rethlake has invented a surgical pin safety guard cap system, and the story of how it came to be is a testament to creative thinking, proof positive that "necessity is the mother of invention," and that "you just never know."

2023 started out well for Mark; he'd found a new job that he liked at a local expediting company. The money wasn't great, but being 6 feet 3 inches tall, a solid 250 pounds and having a strong back it was physically a good match for him. Plus, it allowed him to be home at nights with his partner Tracey and their three dogs.

Rethlake's job involved making deliveries to clients in cities like Tipton, Louisville and Cincinnati. He often had to unload heavy cargoes himself.

On St. Patricks' Day, during a routine delivery to a Cincinnati client, he missed a step off the back of his delivery truck, painfully injuring his right ankle. He couldn't walk or drive, so fellow drivers had to bring him home from Cincinnati.

After an Emergency Room visit, he learned that an orthopedic surgeon would have to surgically repair the tibia pilon fracture in his right ankle. He was also told the recovery would be a long one.

A pilon fracture is a break that occurs at the bottom of the tibia (shinbone), affecting the weight-bearing surface of the ankle joint. Pilon fractures often permanently affect the joint, and mobility can sometimes be permanently impaired.

After surgery, Rethlake was sent home to recuperate with three surgical pins sticking out of his leg: two in the front attached to his shin bone and a long pin through his heel protruding 3 inches on both sides. The pins held the bones in place, providing traction as they mended.

Aside from being uncomfortable when he sat or walked, the pins had sharp ends and they frequently gouged his other leg, poking holes in the furniture and the blankets on his bed.

At first, Tracey covered them with gauze and tape.

That didn't work.

Then, she took apart a pool noodle and handcrafted makeshift covers for the pins, but the pins poked through whatever material she could find.

It had the couple stumped.

And then an idea popped into Mark's head. What if he could design and print something on his 3D thermal printer that would cover the ends of the surgical pins sticking out of his leg?

He'd bought the 3D printer just weeks before on eBay. Since getting it he had enjoyed printing trinkets, little figurines and the like, but he'd never found much serious use for it.

He came up with a design for the project, but there were seemingly a hundred details that needed working out

Fortunately, he had plenty of free time to work while he waited for the break to heal.

During a follow-up with his surgeon, he wore his first set of cap guards to try them out.

His surgeon was surprised and very interested in the design.

"There's nothing like this on the market" he said. "You could probably patent these and make a fortune!"

Mark doesn't expect world fame and glory for inventing something that seems so elemental, but you just never know!

To learn more about the inventor or his other 3D thermal creations, go to

(In the interest of transparency, it should be noted Mark Rethlake is the brother of Bill Rethlake, the author of this story.)

Contact Bill Rethlake at 812-651-0876 or email