Carpal tunnel syndrome: a Q & A with Reid Abrams, chief of hand and microvascular surgery
Carpal tunnel syndrome (CTS) is not a modern affliction. It has plagued workers since at least the Industrial Revolution and the dramatic rise in jobs requiring repetitive, physically stressing movements, from assembly-line workers to meat-cutters and machine operators.
There may be fewer of those jobs these days, but plenty of other ways to develop CTS, from dental hygienists and supermarket cashiers to bank tellers and baseball pitchers.
Women are three times more likely to develop CTS than men, according to the National Institutes of Health, though the reasons are unclear. Evidence suggests 3 percent of women and 2 percent of men will be diagnosed with CTS during their lifetime. Age is major risk factor. Peak prevalence for CTS occurs in women older than 55.
Researchers have been studying CTS and other repetitive stress injuries for years, with clinical trials focusing on preventative measures and behaviors. We asked Reid Abrams, MD, professor of clinical orthopedic surgery at UC San Diego and chief of hand and microvascular surgery at the UC San Diego Medical Center, to talk about what’s known about CTS and how best to treat it.
Q: What is carpel tunnel?
A: The carpal tunnel is an oval-shaped canal at the base of the palm, about 1 ½ inches long and an inch wide. The tunnel is surrounded on three sides by bone and on the palm side by a thick ligament. All of the flexor tendons that control the fingers and thumb run through the tunnel, plus the median nerve. This is the nerve responsible for sensation in the thumb, index, middle and half of the ring finger, plus motor function for most of the muscles at the base of the thumb. CTS is what happens when the median nerve becomes compressed.
Q: How do you know you have CTS?
A: The condition produces a constellation of symptoms, including intermittent or constant numbness or tingling in the thumb, index, long and ring fingers. There can be hand numbness, tingling or burning at night, which awakens patients; swelling or stiffness in the hand; grip weakness; a tendency to drop things.
Not all hand pain is caused by CTS. If the pain is not associated with hand tingling or numbness, it’s not CTS. Also, not all hand tingling or numbness is CTS. Other nerve problems originating in the hand, forearm, elbow, shoulder or neck can also cause these symptoms.
Q: What causes it?
A: CTS occurs when there is abnormally high pressure on the median nerve, so high that the nerve can’t function. That pressure can be the result of an injury that produces sudden swelling, like a wrist fracture, or something else in the canal crowding the nerve, like an engorged blood vessel or intruding muscle.
Most often, the cause is idiopathic or unknown. It’s often activity-related because the dimensions of the carpel tunnel change with different positions of the wrist and fingers. Activities such as driving, tightly holding a book or newspaper while reading, jobs that entail sustained periods of wrist flexion or extension while gripping or pinching, such as maneuvers performed by a dental hygienist, mechanic or construction worker, can bring on symptoms. Some summer activities can set off CTS, such as carrying a surfboard for long distances, cycling or racket sports.
It’s a myth that keyboard use causes CTS. It’s been shown that intense keyboard users have the same incidence of CTS as the general population. This is not to say that symptoms of CTS can’t be brought on by keyboard use. If keyboarding is performed in a non-ergonomic fashion, with the wrists in hyper-flexion or extension, CTS symptoms could arise. Keyboarding can also be responsible for painful problems other than CTS.
Q: How is CTS treated?
A: In the mildest forms, keeping the wrist straight or wearing a splint at night may completely relieve symptoms. Avoiding extreme wrist positioning and repetitive or sustained heavy pinching and gripping can help. Cortisone injections into the carpal canal can also provide temporary relief, though severe CTS usually requires surgery.
Carpal tunnel release surgery enlarges the carpal canal by cutting the transverse carpal ligament. We know the ligament heals with the canal 25 percent bigger. It’s highly successful with rare complications, failures or recurrences.
There are two basic techniques; both work. Endoscopic is done through one or two small incisions using a visualizing camera and a specialized small blade. It produces a modestly faster return to work, but has a three-fold higher incidence of transient median nerve injury. Open surgery through an incision in the palm has a slightly higher incidence of wound healing problems.
ABC News recently reported on 5 common medical tests that the American Board of Internal Medicine Foundation deem unnecessary. A team of researchers with the UC San Diego School of Medicine and the Urinary Incontinence Treatment Network have one more the add to the list: unnecessary invasive bladder tests before incontinence surgery.
Charles Nager, MD, director of Urogynecology and Reconstructive Pelvic Surgery at UC San Diego Health System and researchers found that post surgical outcomes for stress urinary incontinence (SUI) were just as successful for women who had an office check-up alone. More here
From Shattered Elbow to Ground Breaking Mountain Climbs
Mountaineer, Ben Horne, has accomplished athletic endeavors that most people never even attempt in a lifetime – he’s finished marathons, climbed Mt. Whitney, ran the Grand Canyon from rim to rim, and most recently, made the first winter ascent of the Evolution Traverse – an eight mile route that links nine peaks in the Sierra.
“Our team climbed 36 hours over four days, enduring temperatures as low as negative seven degrees Fahrenheit,” said Horne, an economics graduate student at UC San Diego.
But three years ago, Horne never thought he would step foot on a mountain again after shattering his elbow during a long distance bike ride.
“I thought this was it – my lifestyle is over,” said Horne.
His elbow was crushed in five pieces upon impact.
“Because he is young, and an athlete, the team wanted to preserve his natural bone. We also wanted to avoid a prosthetic replacement, which is commonly used but unpredictable in terms of longevity. As a cyclist, I understood the flexibility and stability that Ben would require for cycling, climbing and swimming well into the future,” said Reid Abrams, MD, chief of hand and microvascular surgery at UC San Diego Health System.
During a delicate two-hour surgery, Abrams’ team re-built Horne’s elbow with a series of strategically placed plates, screws and pins woven with wire. After four months of healing, a second surgery was performed to remove hardware and to reduce bone adhesions to improve range of motion.
Now, due to surgery, physical therapy and Ben’s tenacity, he can fully flex his elbow.
“For mountain climbing, you have to be able to pull yourself up under rigorous conditions,” said Horne. “Since my surgery with Dr. Abrams, I’ve been able to climb at even higher levels. I’m a stronger athlete now because I had to learn different sports from cross training during the recovery process.”
“As a surgeon, and someone who has recovered from his own hand injury after a biking mishap, I understand the need to get back to doing what you love,” said Abrams. “I encourage every athlete to continue to pursue their passion after an accident. With the right surgery and follow-up care, the results can be amazing. Ben proves it every day.”
Since the surgery, Horne has completed an ironman and climbed Mt. McKinley in Alaska, referred to as “Denali,” which stands 20,320 feet tall and is the highest mountain in the United States.
“These latest accomplishments are a big deal for me personally. As my rock climbing group says, ‘go big and don’t cut corners,’ and Dr. Abrams made it possible to do so – I am forever grateful.”
Bridging the Gap: three questions about nerve grafts
On February 14, a team of UC San Diego Health System surgeons performed a complicated cancer surgery on Hall of Fame outfielder, Tony Gwynn. The process involved utilizing a nerve graft from Gwynn’s neck to reconstruct the facial nerve.
We asked Justin Brown, MD, director of the Neurosurgery Peripheral Nerve Program and co-director of the Center for Neurophysiology and Restorative Neurology three questions about this type of nerve grafting.
Question: Where are nerves for graft typically harvested? Can nerves be donated?
Answer: Usually a nerve is harvested from a part of the patient that is not critical. We often use a sensory nerve from the side of the foot or inside of the arm, often a region that is close to the nerve being reconstructed as in this case. The removal of this nerve from its normal location causes an area of numbness, but usually it is small and not a problem. It does not cause any weakness to take these nerves because they are purely sensory nerve. The nerve is a graft – that is, a bridge to replace the piece of nerve that is missing.
An actual nerve transplant from another person is possible, but requires taking immunosuppression drugs. In the case of a nerve transplant, however, a patient wouldn’t have to take these drugs forever as they would with an organ transplant. Nerve transplants are therefore only used in severe nerve injuries when the patient’s own nerve grafts do not appear to be enough.
Q: How long does it take for nerves, once grafted, to work?
A: In this diagram, the part of the nerve that still is in contact with the spinal cord (A) has the “wires” or axons that need to grow through the graft (C) to the paralyzed muscle in order to recover it. Those wires grow through the graft and into the distal nerve (B) and finally to the muscle. They typically grow at 1 mm per day-a little less than the thickness of a dime. So measure the distance from the proximal stump (A) to the muscle (not pictured) and you have a rough idea of how long it will take. Typically it is three months for a short distance and even more than a year for long distances.
Q: Do nerves have memory? How does a transplanted nerve know how to behave once it has been moved?
A: It’s all about the “wires” or axons within the nerve. With a nerve graft we are trying to help the original wires re-grow to the original target so often there’s nothing to learn. In complex nerves sometimes the correct wires do not go to the correct target. When this happens in the face it can cause the whole side of the face to contract instead of just the mouth when a patient tries to smile. This is called “synkinesis.”
When the proximal nerve stump (A) is not available for a graft reconstruction, sometimes we use a nerve that originally went to a different target muscle to bring axons to the distal nerve stump (B). This is called a nerve transfer. For the face, part of the nerve to the chewing muscle (masseter) can be used to recover a smile. When this is done the smile usually occurs whenever the patient bites down (the movement that made this nerve work when it was involved in chewing). With time the brain can learn which axons are going to the face and which are still involved in chewing and the patient may learn to smile more naturally, without biting down.
Dr. Alan Hemming discussing how the patient’s liver was removed from the body, cooled, treated and returned tumor free.
Radical Surgery Saves Life of Young Mom, California First
Liver Removed, Reconstructed, Re-Implanted
A team led by Alan Hemming, MD, transplant surgeon at UC San Diego Health System, has successfully performed the west coast’s first ex-vivo liver resection, a radical procedure to completely remove and reconstruct a diseased liver and re-implant it without any tumors. The procedure saved the life of a 27-year old mother whose liver had been invaded by a painful tumor that crushed the organ and entangled its blood supply.
“During a 9-hour surgery the team was able to remove the basketball-sized tumor,” said Hemming, professor and surgical director of the Center for Hepatobiliary Disease and Abdominal Transplantation (CHAT) at UC San Diego Health System. “This is a surgery that carries a 15 to 20 percent risk of mortality. In this case, the patient would not have survived if she did not have surgery. This was the only way we could save her liver and her life.”