The veteran pilot and flight instructor reviewed emergency operations with his student, the owner of the airplane, as they flew at 2,500 feet on a sunny spring Colorado day.
William Snodgrass had taken off about an hour earlier from a local airport in northern Colorado. The weather was perfect. It was a beautiful day for flying. Nothing was amiss. The student had the controls and was practicing a specific set of maneuvers, all part of his Federal Aviation Administration-required flight review that tests a pilot’s skills.
“While flying out to the practice area (near Eaton, Colorado), we were talking about how to land in an emergency,” Snodgrass said. “As part of the flight review, we also do a maneuver called a power-off stall where you pitch the airplane nose up so that the airplane loses speed and stalls. You must learn how to recover properly. I had just demonstrated it, and then it was his turn. As you start to do it, you add full power.”
But something went wrong. The throttle wasn’t adjusting the plane’s power. Snodgrass quickly took over controls from his student.
“I grabbed the throttle and moved it to do something, and sure enough, it was loose,” Snodgrass said. “The cable that powers the engine had disconnected from the carburetors. When that happened, the engine went to idle. I had no power.”
Although the plane’s propeller was still moving, there was no way to power the single-engine Pipistrel Alpha Trainer.
“I tried to add power using the choke, but that wouldn’t work,” Snodgrass said. “In disbelief, I pulled the throttle cable all the way out of the cockpit, and I’m looking at it! There was nothing we could do for the engine. I made the mayday call with all the information. I told my student to tighten his seatbelt.”
The two had just reviewed emergency landings. Now they had to perform one. Snodgrass started his approach toward what he thought was a flat field. As he got closer, he noticed the slight tilt to the ground and berms in his path. But with no power, there was no changing course. The airplane’s main wheel touched down first. The plane’s nose caught the dirt berm, flipping the plane upside down.
As the propeller dug into the earth, the impact forced the plane’s engine into the cockpit, crushing Snodgrass’ right leg, and breaking his tibia, fibula and ankle. He also fractured his left ankle.
Despite the difficult landing, Snodgrass had done his job as a pilot. His passenger walked away with only bruises, and no one on the ground was hurt.
Snodgrass crawled onto the plane’s wing and waited for first responders. In about 20 minutes, paramedics had loaded Snodgrass into a helicopter headed for UCHealth Medical Center of the Rockies in Loveland, Colorado, the first and only Level I Trauma center in northern Colorado.
Once doctors began to work on him, Snodgrass learned he had multiple fractures, including one of his tibia, a vital weight-bearing bone in the lower leg. As Snodgrass began to recover, he volunteered to participate in a groundbreaking study with trauma experts at UCHealth and mechanical engineering researchers at Colorado State University (CSU).
Their findings could help speed healing and reduce complications for other patients who suffer similar fractures.
The benefits of a Level I Trauma center close to home
Level I Trauma centers are equipped to deal with the most acute trauma cases. They offer around-the-clock coverage by trauma surgeons and have specialists like orthopedic and neurosurgery doctors standing by to jump into action. These facilities must also be leaders in trauma prevention and education and conduct trauma research to improve protocols and outcomes.
Snodgrass’ injuries weren’t life-threatening, but the depth of his recovery would determine his quality of life. One of the biggest health challenges he faced was how well his weight-bearing bones, like the tibia, would heal.
Snodgrass’ tibia fracture became one of the first that doctors monitored as part of a study to improve recovery from tibia fractures.
Snodgrass was eager to participate in the research.
“As human beings, there is nothing more important than each other,” Snodgrass said. “We need to do whatever we can to help the medical field. It’s to our benefit to help out.”
Looking at tibia fractures and recovery complications
Snodgrass’ recovery is helping doctors gain insights into a common post-surgical complication that affects about one in five people who deal with a tibia fracture.
“The tibia is a weight-bearing bone with a higher nonunion or malunion rate,” said Dr. Julie Dunn, a UCHealth trauma surgeon and medical director of trauma research for UCHealth Medical Center of the Rockies.
A nonunion or malunion of a tibia fracture happens when the tibia doesn’t heal properly, which sometimes occurs inexplicably in about 20% of patients. It can result in chronic pain, restricted function and the need for additional surgeries to correct the bone healing complication.
Malunion complications are well known to physicians, but doctors can’t easily predict which patients will struggle to heal properly, said Nikiah Nudell, manager of the trauma research team at Medical Center of the Rockies.
Snodgrass helped the team by allowing them to study his recovery from the tibia fracture.
The team began by doing X-rays of Snodgrass’ fractures, grading each on the extent and location of the break. Doctors analyzed the fracture grades and assessed Snodgrass’ physiological status.
To fix Snodgrass’ tibia, surgeons inserted a specially designed metal rod, secured with pins, into the canal of the tibia. Dunn said it is the standard treatment for a fracture in a weight-bearing bone. The team also addressed his other, less severe fractures. Snodgrass remained in the hospital for a few days as he recovered.
Trauma research is part of a Level I center
“After the crash and surgeries, the next step was healing,” Snodgrass said.
When a tibia fracture like Snodgrass’ begins to heal, the body starts regenerating primary cartilaginous callus, or soft tissue. This callus later undergoes a process that restores blood flow. It then begins to calcify, which eventually restores normal bone structure.
Doctors use X-rays to evaluate how well a person is healing. But both patients and medical providers must be tolerant of the process. It takes about six months after surgery to see how well the calcification is working.
Some patients learn then that they need to go back to the operating room.
“It’s a huge burden on the patient because, in six months, they are back in surgery,” Dunn said. “We often have to remove or revise the rod, which increases the risk for infection. And there is no guarantee it will heal correctly. There is ongoing pain and discomfort. And the patient is on antibiotics, which have their own side effects.
“This issue with a patient having to come back and go through maybe one or more operations to correct the problem is a financial and emotional burden for them,” she said.
The researchers wanted to find a way to identify nonunion and malunion tibia complications earlier — before you can tell using X-rays. If they could do that, doctors might be able to prevent additional surgeries. Snodgrass said he hopes his participation in the tibia study can do just that.
The tibia fracture study
After leaving the hospital, Snodgrass agreed to be evaluated weekly as part of the study. The device used for assessing healing has been a decade in the making, conceptualized by Christian Puttlitz, head of the mechanical engineering department for CSU and lead investigator for this study, and designed and built by Labus.
“The device works by measuring the bending stiffness of the tibia,” said Kevin Labus, a research scientist with CSU and co-investigator on the study.
Patients place their leg inside the device, positioning it much as they would if they were resting their leg. The machine then measures the movement of the fractured bone as a small amount of pressure is applied.
“When a bone is first fractured, it will bend a lot, but as it heals, that decreases,” Labus said. “The device measures the amount of bending. It uses a radio frequency antenna that senses the amount of movement under the applied load. Stiffness is calculated from the load and the movement.”
And stiffness helps determine how the bone is healing, in hopes, much quicker than could be identified via X-rays.
The load applied to the leg is so small that patients don’t feel any pain during the five minutes it takes for the device to evaluate the bone, Labus said.
So far, 11 participants have gone through the study and researchers have now adapted the device so it can be sent home with patients, allowing them to perform daily readings. The device automatically transmits the information to a database.
“This is a feasibility study, so we aren’t yet sharing the data with the doctors or patients,” Labus said. “The ultimate goal is to send the information to the doctor so they can identify and correct nonunions or malunions much earlier.”
While Labus reviews the data, Dunn keeps an eye on each participant’s medical records and X-rays, assuring they get the standard treatment for a tibia fracture. At the end of the study, researchers will determine if this “direct electromagnetic coupling (DEC) antenna” approach identifies bone healing complications earlier than the traditional approach to care. Snodgrass’ results will help with this determination because, as he found out months after his injury, he became one of those patients who experienced union complications and required additional surgery.
While Snodgrass’ recovery wasn’t ideal, he’s philosophical about how he’s done.
“My bones didn’t calcify properly,” he said. “I’m 61 years old, and the world keeps turning.”
During an additional surgery, doctors gave Snodgrass a new, larger titanium rod to promote better bone growth. He’s currently working through his recovery and is grateful that he’s able to work and continue to do the other things he loves, like flying.
He hopes other patients will encounter less bumpy flight paths, courtesy of the study findings.
Labus is eager to share the preliminary findings, but those results may be another year as the study is still taking participants through early 2023.
“We hope to show a distinction between healing and non-healing,” Labus said. “The next steps would be a larger observational study followed by a clinical trial combining this measurement with early interventions to improve healing.”
Trauma research and partnerships continue at UCHealth
Nudell said the team recently applied for a grant to do similar work on breaks in upper arm bones. These breaks often happen in older people due to bone degeneration. The patient’s age can hinder their ability to be a good candidate for surgery. Thus, being able to monitor the healing process and intervene earlier benefits patients.
“There are great benefits that come from a health care system to be able to partner with a university,” Nudell said. “CSU has a lot of researchers with good ideas. We provide patients access to those studies and the health system investigators who partner on this research.
“We work daily with at least seven different departments and labs at CSU. We collaborate on research projects involving trauma processes, paramedic leadership and patient diagnostics. We have a biobanking study focused on long COVID. We are also involved with the CSU College of Veterinary Medicine, examining how medicine translates between humans and animals.”
As for Snodgrass, even though his path to recovery wasn’t simple, he’s pleased with his outcome.
“I’m grateful to be alive and for the work they did at UCHealth,” Snodgrass said. “That was why I was so willing to participate in this research.”
Snodgrass said he had to work through his depression and fear after the accident, but he’s now overjoyed to be flying and teaching again. He’s been sharing his experience with other pilots in hopes of helping them better understand how the mind and body respond to emergency situations and trauma.
Dunn said that participation in clinical research is vital to advancements in health care treatments and processes.
“We have a gracious patient population that participates in these studies, which allows us to provide some of the most modern and cutting-edge care,” she said. “And these studies help us look at gaps in care and impact the treatment of our patients.”