Trialing a nerve transfer procedure with promising results

southlake h and onlnieImagine the frustration of not being able to put your car key in the ignition.  Or not being able to hold your dog’s leash to go for a walk.  Most of us take these abilities for granted.  For people with severe nerve injuries, this is often their reality.

At Southlake Regional Health Centre, plastic surgeon Dr. Casey Knight and her team are seeing encouraging improvements with a promising new surgical technique aimed at helping patients regain hand function better and faster.

It’s called a nerve transfer.  It is a surgical technique that helps patients who have severe nerve injuries.  Dr. Knight, who completed special training in hand and peripheral nerve surgery, joined Southlake in 2010.  Frustrated by the poor options available to certain patients with compressed nerves, she was eager to begin performing this innovative procedure, which was new to Southlake.

Here’s how it works.   Using a microscope, Dr. Knight goes into a “sick” nerve and identifies which part of the nerve controls motor (muscles) and which part controls sensation.  She then cuts a nearby healthy, expendable motor nerve and delicately plugs it into the motor component of the sick nerve.   The idea is that the healthy nerve will help the sick nerve.


Dr. Knight has been trialing this new technique here at Southlake on patients who have nerve compression at the elbow level – the affected nerve is called the ulnar nerve.   The ulnar nerve is very important for hand function because it controls the small muscles of the hand, and it also provides sensation to the small finger and part of the ring finger.

Essentially, when the nerve gets compressed at the elbow, the brain is talking to the nerve but the message is stopped at the elbow and never reaches the hand.  The nerve is there, like a pathway, it’s just not conducting properly.

The bigger problem is that when the muscles stop hearing the nerve signal they start to atrophy, or waste away.  That leads to hand weakness and dysfunction in addition to numbness.

In the past, the procedure involved releasing (decompressing) the ulnar nerve at the elbow and positioning it so that it was less vulnerable to further compression. With this standard procedure the ulnar nerve regenerates at approximately one millimetre per day.  By the time the nerve regenerates from the elbow to the hand there’s a risk that the muscles could be permanently damaged.

The exciting thing about a nerve transfer is that it creates a shortcut.  The idea is that you take a healthy expendable donor nerve, plug that healthy nerve into the sick nerve at the forearm level, creating a much shorter distance to send signals to the muscle.

This allows the muscle in the hand to hear the signal.   The donor nerve is often described as a babysitter.   “While the sick nerve recovers, there’s a babysitting nerve nearby helping out – making sure that signal still gets to the muscle,” Dr. Knight says.

Dr. Knight says there is promising evidence that in many cases, hand muscles will begin to recover after this procedure.   In her case series of eight patients to date, “they recover faster, with better muscle function than we have seen in the past.  It is still early, and we are talking small numbers, but it is an encouraging trend.”

For Dr. Knight it’s all about working together.  “This is multidisciplinary care in action: the neurologist identifies the problem, I perform the operation, and the hand therapists guide the post operative rehabilitation.  It is truly a team approach,” says Knight.

She feels very fortunate Southlake’s Hand Clinics has actively-engaged hand therapists.  This allows patients to be seen by surgeons and hand therapists at the same time.  Dr. Knight and Kathy Wilton, an Occupational Therapist and certified Hand Therapist, work together at the Clinic.  They have also worked together on all of the nerve transfer patients at Southlake streamlining both surgical and post operative care.


Thomas Sagar is one of Dr. Knight’s patients who chose to try the new procedure after being diagnosed with severe ulnar nerve compression leading to muscle atrophy in his hand.  He says he had no idea that his condition was so serious until he saw his family doctor who sent him to Dr. Knight days later. He was grateful to Dr. Knight for helping him so quickly, “I think the world of Dr. Knight. It was a serious operation – it took a while to get over it. Kathy was wonderful doing the physio[therapy]. I was fearful after the dressing came off, and she really helped me get through it.”

Sagar’s wife Jane agrees. The two have been married for almost 44 years. They go to all their appointments together. She is pleased and grateful for the excellent care her husband received at Southlake, “Dr. Knight gave my husband a choice (between the two operations) and now his hand is as good as new. After the surgery, Dr. Knight came to me and answered all my questions. She is wonderful.”

Dr. Knight is quick to credit the hand therapists like Wilton with helping to get patients better faster.

“Without the dedicated work of our hand therapy department, we simply wouldn’t see the kind of positive outcomes that we do, not just in nerve injuries but in many other hand-related injuries and conditions.  Our hand therapists are doing a fantastic job.”

Dr. Knight and her team are working together to track patient results, taking quantitative measurements of hand strength to show improvements.  Patients also undergo nerve conduction studies before the surgery, and then one year later, to further quantify the effect of surgery.

“Subjectively, patients are telling us that their hands are beginning to work again, allowing them to perform their daily activities independently.  Objectively, we are seeing their strength and sensation measurements improving.  We are excited to hear patients tell us that they are able to do activities that they couldn’t do before,” says Dr. Knight.

Wilton says the beauty of this operation is that it will help muscles recover.  She sees patients start to be able to do the little things they couldn’t do before, in a very short time.  “Hearing about how happy one patient was to be able to hold his dog’s leash and take the dog for a walk again is very rewarding.  If this surgery were not available, people would still have pain and wouldn’t be able to use their hand.  Now patients talk about how grateful they are.  In a matter of weeks I start to see muscles coming back, hand function returns, even the appearance of the hand is so much better.”

Dr. Knight is also grateful, “we are able to perform this surgery in Newmarket because I have support to do it — from my colleagues, the OR and the hospital, the patients, and the hand therapists.  I’m proud of the fact that we are offering this procedure at Southlake.  Community hospitals are bringing services to patients that have traditionally been available only at larger academic centres.”


This technique was championed by Dr. Susan Mackinnon.  Canadian-born and educated, Mackinnon is a professor of plastic and reconstructive surgery at Washington University in St. Louis, Missouri.  Her life’s work and research has been around peripheral nerve surgery, and she has pioneered a number of techniques.  Dr. Knight says Mackinnon’s results are impressive.   In fact, they suggest that this may become the new standard of care for certain patients who have injuries that fit the criteria.

Dr. Knight has been at Southlake for the last four and a half years.  She became passionate about peripheral nerve surgery during her residency training at McMaster University and credits great mentors with peaking her interest in the field.

She describes her current surgical practice as varied, and she loves being able to work with patients with a variety of illnesses and concerns.  Her focus is on reconstructive plastic surgery.  In addition to nerve surgery she performs hand surgery, breast surgery, and skin cancer surgery.

“I try to maintain variety in my practice so that I can serve my community well.  Patients like to be cared for near their home, and I believe we should strive to provide them with this option whenever possible.”

She describes the patients here at Southlake as remarkable.  “There is a critical trust relationship with patients, especially with new procedures,” says Knight.   When she offered patients the option to try this new procedure, they all accepted it.   “It’s humbling, and it will contribute to our knowledge in ways that helps others.  This is key to evolving, innovating, and improving our care.”