News from Cedars Sinai

Rewired From Head to Toe

Hailing from Park City, Utah, Riley Mulholland enjoyed an upbringing steeped in the vibrant active outdoor sports culture of his hometown. From an early age, Mulholland took to the slopes, played football and lacrosse; he was the definition of a multisport athlete.

Riley Mulholland (right) playing lacrosse. Photo courtesy of Ben Anderson.That is, until May 2020, when his active lifestyle took a sudden downhill turn.

Two months after Mulholland’s high school junior varsity lacrosse season came to an abrupt end due to the COVID-19 pandemic, a playful roughhousing wrestling match with friends at a park ended with a devastating injury.

“I blew out my entire knee and tore everything–my ACL, my LCL, my PCL–my IT band tore off of my femur, my kneecap dislocated, and my peroneal nerve also tore,” said Mulholland. “After that, everything from my knee down was paralyzed.”

Mulholland’s right leg was left with damage to his peroneal nerve–a branch of the sciatic nerve located in the lower leg. After undergoing reconstructive knee surgery, Mulholland developed foot drop, a condition characterized by the inability to lift up and roll out the foot.

“As soon as I met with an orthopaedic surgeon, I found out that my athletic career would be pretty short-lived and that it was going to be really hard to recover from a nerve or foot drop injury,” said Mulholland.

The National Institutes of Health estimates that over 120,000 people are affected by foot drop each year. However, the actual number may be higher, as some patients may go unreported or undiagnosed.

Riley Mulholland (right) with his mother, Jennifer Mulholland. Photo courtesy of Jennifer Mulholland.Ten months after his knee surgery, Mulholland could still not move his foot and was advised by medical experts to wait to see if his peroneal nerve would reawaken on its own.

“There was a lot of waiting and no great solution. I became antsy,” said Mulholland’s mother, Jennifer Mulholland. “Here’s a three-sport athlete with remarkable physical and mental abilities, that I just knew if I asked for help a solution was out there.”

After speaking with more than 15 specialists from throughout the U.S, the solution began to unfold after a conversation with orthopaedic surgeon Glenn Pfeffer, MD, director of the Foot and Ankle Surgery Program at Cedars-Sinai.

“Dr. Pfeffer is our angel doctor,” Jennifer Mulholland said. “He personally called us and said, ‘I've got your guy,’ and that it wasn’t him, but one of his colleagues, Dr. Seruya.”

Thirty minutes later, the Mulhollands were talking with Mitchel Seruya, MD, director of the Peripheral Nerve and Microsurgery Fellowship at Cedars-Sinai Medical Center and Guerin Children’s.

“Dr. Seruya’s approach was not just surgical; it was a lifeline,” recalled Jennifer Mulholland.

A Window of Time

Riley Mulholland (left) is examined by Mitch Seruya, MD, after surgery. Photo courtesy of Jennifer Mulholland.Seruya, who is among the few surgeons in the U.S. who perform innovative electrical bypass techniques called nerve transfers, saw the potential for recovery, but he’d be working against time.  

“Unfortunately, so many patients are told to give nerve injuries time to heal, but what they don’t realize is there is an expiration date, or a time clock, working against you,” said Seruya. “Meaning that by 12 to 18 months, these nerve injuries become irreversible.”

Although it had been 11 months since getting injured, Mulholland was a candidate for a nerve transfer surgery, a procedure that involves rerouting healthy and expendable nerves to compensate for damaged ones, effectively restoring the electrical signals needed for proper muscle function.

“It's a way of borrowing electricity from one functional nerve to restore movement in another area affected by nerve damage,” said Seruya. “In Riley’s case, we rerouted the nerve from his big toe to the paralyzed muscles in the front of the leg.”  

During surgery, Seruya went into Mulholland's inner calf area, found his toe electricity, isolated it, used a nerve stimulator to test and make sure the toes were bending strongly, then divided the electricity to route it from his inner calf area out to the front of the leg.

Learning to Walk

Six months post-surgery, Mulholland could flex his foot to lift up and roll out his ankle, the first step on the road to his recovery.

The process of walking is now completely different for Mulholland. Now, when Mulholland’s brain tells his toe to move, his foot moves instead. That’s because the nerve that was once connected to his big toe is now connected to the muscles that move his foot and ankle.

Riley Mulholland after receiving his high school diploma. Photo courtesy of Jennifer Mulholland.“I never knew that walking was so important or how much brain power it actually takes to do a stride,” said Mulholland. “Thinking about having to walk with every stride, ‘left, right, left, right,’ it doesn’t really wrap around your mind unless you experience it.”

Mulholland ultimately returned to the lacrosse field to go on to help the team win two back-to-back state championships, was crowned as the second-leading scorer, and made the all-state team his senior year.

Today, Mulholland is the only starting freshman on San Diego State University’s lacrosse team. As for his education, Mulholland is now studying neuroscience because of his passion for the mind-body connection, which all started with that fateful knee injury.

“This was my comeback kid,” Jennifer Mulholland said. “What he was able to overcome, how he overcame with the help of Dr. Seruya, really giving him this fortitude and the possibility to regain motion, regain the ability to walk normally again and regain the ability to play on the field and to absolutely shine like the most incredible star.”

Learn more about the Brachial Plexus and Peripheral Nerve Surgery program at Cedars-Sinai.