Man chases dream at para-cycling world championships after reaching elite level in life-changing prosthesis
Jason Macom feels most alive when life goes by in a blur. He thrives in the velodrome, a cauldron of speed that rewards endless hours of lung- and leg-busting training, mental focus and fearlessness.
But over two spans in the past 15 years, the adrenalized world of track cycling came to an abrupt halt for Macom. The first (2010 to 2015) came after a severe leg injury in a bicycle accident that eventually required an amputation below his knee. The second (2021 to 2024) saw his para-cycling career shelved by painful chafing and bursitis where his residual limb met a traditional socket prosthesis.
The latter period pushed Macom, who won his first sprint-race national title in 2018, to the brink of despair. By 2021, "I was just in my wheelchair, using forearm crutches and no prosthesis, no socket," said Macom, who also won two silver medals at the 2020 world championships. "I couldn't do anything (active). It was very difficult, very challenging."
By the end of 2023, the pain was so severe he couldn't put a liner on his leg. As someone who had willed himself to elite-level racing both pre- and post-amputation, Macom struggled with the most basic of tasks. His depression deepened and, for the second time in roughly a decade, the walls closed in. "I was having to ask for help in every aspect of my life. It was a dark time."
Discovering OI surgery
Then, a social media post offered him a ray of hope. The post described osseointegration (OI) surgery and led Macom to Jason Stoneback, MD, and the Limb Restoration Program (LRP) at CU Anschutz.
One of the country's foremost OI surgeons, Stoneback founded the LRP in 2013. He is an associate professor in the Department of Orthopedics at the CU School of Medicine and is chief of orthopedic trauma and fracture surgery at UCHealth University of Colorado Hospital.
Macom became a candidate for a bone-anchored limb, and Stoneback performed surgery in August 2024. A specialized titanium implant was inserted into Macom's tibia, allowing the bone to integrate into the implant, which includes a portion - a dual cone - that protrudes outside the skin. A prosthetic limb connects to the dual cone, making it easy to click on and off.
Macom's life changed overnight. He underwent three weeks of physical therapy at the hospital followed by joyful - and hike-filled - reunions with his partner, Julie, and dog, Asher, also an amputee, back home in Colorado Springs.
"I went home, and I started walking with my dog every day. We would walk to the grocery store, put in a couple miles - it was a massive, life-changing experience," he said. The time-consuming process to roll on a liner, pull on a sock and jockey the socket into place, has been replaced by a click-on prosthesis.
"Now I open this lever, pull this button and it's off," Macom said. "I'm up and onto it in a matter of seconds."
'Profound change'
The athlete is also back onto his beloved bicycle, having qualified for the 2025 Para-cycling Track World Championships in Rio de Janeiro. Macom is one of six male racers who will represent the United States in mid-October.
While his team was "very in tune" with Macom's previous high level of athletic performance, Stoneback said the initial priority was to ensure the bone-anchored limb healed without complication and that the cyclist could resume daily activities. "These are the goals we strive for first," he said. "Jason then has taken that, obviously, to an elite level and really excelled. It's impressive to see."
In addition to a recent study that examined the reliability and validity of the Colorado Limb Donning-Timed Up and Go (COLD-TUG) test, Stoneback's team has followed LRP's bone-anchored limb patients since day one, tracking how they perform in various patient-reported functional outcome measures.
Results show the patients wear the new prosthesis much more than the socket style, and "we've found that they have improved balance," he said. "There's a scale called the WHODAS 2.0 (World Health Organization Disability Assessment Schedule), which is a scale of how disabled someone is. After receiving bone-anchored limbs, they score as if they're able-bodied, or not an amputee. So, it's a profound change, and I think that shows how game-changing this is to them."
Reconnecting to his bike
In Macom's case, extra attention was paid to the torque he would apply to his prosthesis as a pro cyclist. During a recent CU Anschutz visit, Macom and his team refined the alignment of his cycling-specific prosthesis, significantly improving his stability and power transfer.
To measure power balance, a meter reads the torque levels of each leg pushing down on the pedals. "I worked in bike fitting over the years," Macom said, "and now my power balance is better than some guys that don't have any disabilities at all."
Because the prosthesis and metal rods are integrated with the skeleton, OI patients gain "osseo-perception," allowing them to feel vibrations and the ground (or pedal) - even surface textures.
Macom now feels connected to the bike, and he can fully push down through each pedal stroke. Conversely, with a socket, "you almost have to wait until the pedal is down at nine o'clock before you can push. Also, you can get this little hop and suddenly your foot flops off the pedal."
It's all paid off for Macom, who at 44, is still competing in para-cycling and even non-para-cycling events at the highest levels. "I love to mix it up with guys without disabilities as well," he said of able-bodied master's (35 and over) races.
'Honor this opportunity'
Three inches. That's how close the Arkansas native came to winning gold in the scratch race - a high-speed track race where cyclists jockey within centimeters of each other - in Toronto in 2020. "I led the final lap, and one guy came over the top of me just right on the finish line."
Macom gets emotional when talking about what it means to wear the USA colors at the world championships.
"The biggest thing for me is a responsibility to honor this opportunity and to push myself as hard as I can … and giving myself the chance to try to win and be at the end of the race when it counts and go for the move that puts me across the line first."
Cutting-edge biomechanical research
Stoneback and Danielle Melton, MD, professor of physical medicine and rehabilitation and director of amputation medicine and rehabilitation for the LRP, said their program continues to explore new ways to advance the functionalities of bone-anchored limbs.
Melton said advances in lighter-weight, bone-anchored prostheses are enabling amputees like Macom to achieve their athletic goals.
"Our OI team leads the field in biomechanical research funded by the Department of Defense, NIH and industry, making these surgical and prosthetic advances possible," she said. "By having clincians and researchers working side by side in the lab and on the track, our research allows elite athletes with limb loss to push the envelope in a safe, responsible way."
The LRP has cared for patients who became para-athletes after OI surgery, but Macom is unique in that he was an elite athlete before his amputation. He was a BMX racer - bicycle motocross - before shifting to road and track racing in his early 20s. One day in 2010, while playing bike polo on a roller-hockey rink, he rode fast into a corner and put his leg down. His ankle exploded. Despite many attempts to repair the damage, the leg required amputation in 2015.
Although it was a "rough time of my life," he remembers watching the Paralympic Games on TV from a hospital bed. One of the events was track cycling. His world, which had closed in for the first time, opened back up before his eyes.
"The day I got the socket prosthetic, I jumped on my bike and started trying to figure it out," he said.
Macom's relentless drive is infectious. "He's showing us we have to push the envelope," Stoneback said, "but we have to do it in a responsible, safe manner. And that's what a lot of our research group is doing - how we're thinking and moving this technology forward."
Likewise, Macom called Stoneback's multidisciplinary team "amazing." He said they expertly managed his post-surgical pain and rehabilitation process. Now he confidently clips into the pedals and connects to the bike as his body sways side to side in full sprint. He clocked 65 kilometers an hour (over 40 mph) at a recent training session in Colorado Springs.
Pondering a life-changing shift
"It's how I could ride before I got hurt," Macom said. "I can't say enough about how life-changing this new technology has been. I feel the freedom of going fast, hiking in the mountains, or just being able to take my laundry downstairs."
When he rolls his bike to the starting line in Rio, Macom will be thinking of where he was a few years ago. He'll replay the three-inch gap in Toronto. He might ponder how, if he wins this time, his spine will tingle at the playing of the national anthem.
He will think about his doctors, physical therapists, Julie and his three-legged dog. He'll remember the group of fellow OI patients who gathered at CU Anschutz to try out new prostheses and share stories. "We were all talking, and I remember one lady said, 'I really hope you make the U.S. team, and you'll be out there (at the world championships) representing us all.'"
Then he'll hear the start, push down hard on his pedals and chase his dream. Jason Macom will be back in his element, feeling the freedom of speed and seeing the blur again.
