Carpal Tunnel Syndrome: Why Waiting Too Long for Surgery Can Be Risky
When fingers tingle or go numb at night, carpal tunnel syndrome may be to blame. Hand surgeon Prof. Dr. Helen Abel explains when a splint is sufficient, why waiting too long can cause permanent nerve damage, and what the chances of recovery are after surgery.
Few parts of the body are as intricate as our hands. Tendons, nerves, and blood vessels are packed into an extraordinarily tight space, working together with remarkable precision during every movement. Even minor changes can cause significant problems. One of the most common conditions is carpal tunnel syndrome, in which a nerve in the wrist comes under pressure.
Prof. Dr. Helen Abel is a hand surgeon based in Munich. In this interview, she explains which symptoms should be assessed early, what progress has been made in treating finger arthritis, and why even cutting an avocado can be dangerous.
Carpal Tunnel Syndrome: What Lies Behind the Symptoms
Professor Abel, carpal tunnel syndrome has almost become a widespread condition. What causes it?
It really has become extremely common. The hand is supplied by three main nerves, which play a key role in both sensation and muscle function. One of them is the median nerve, which runs from the forearm through a narrow canal into the palm.
Think of this canal as a small tunnel: the many flexor tendons of the fingers run along the bottom, the sides are lined by bones, and a firm band crosses over the nerve. This band is a remnant of our evolutionary past, from when we moved on all fours. It protects the nerve but has very little flexibility.
Over the course of a lifetime, space inside this canal can become restricted for a variety of reasons. During pregnancy, for example, fluid retention can be a cause, and in older age, swelling of the tendons is a common factor.
Because the band is so rigid, the nerve has nowhere to go. It becomes compressed and responds by swelling, which leaves it with even less space — a true vicious cycle. The earliest signs are usually pain and fingers falling asleep.
Does carpal tunnel syndrome always require immediate surgery, or can it be managed conservatively?
An operation is not always necessary. What matters is how severely the nerve is already compressed. The nerve functions much like an electrical cable. A neurologist can measure how well electrical signals are still being transmitted, whether a constriction is actually present, and how significantly nerve conduction velocity has already been affected.
That said, certain symptoms make surgery the more advisable course. Many patients struggle with fingers falling asleep at night and severe pain that makes it nearly impossible to sleep.
This is often because the wrist bends unconsciously during sleep, placing additional pressure on the nerve and producing pain and tingling.
For mild cases, a night splint is worth trying first. It holds the wrist in an extended position and prevents further compression of the nerve. In some cases, the swelling does subside as a result. Progress must be monitored carefully, however.
Particular caution is needed with pregnant women. Symptoms are often attributed to fluid retention that is expected to resolve after delivery. But even if a woman only develops symptoms at week 30 of her pregnancy, simply waiting another ten weeks for relief is not a safe assumption.
After delivery, it can take another three months or so for the fluid retention to subside. In cases of severe compression, that window may already be long enough to cause permanent nerve damage.
That is why every case must be assessed individually. For a mild presentation, however, conservative treatment is certainly a viable option.
Can carpal tunnel syndrome affect both hands at the same time?
Yes, that is actually quite common.
For surgery, there is an open technique and an endoscopic technique. What is the difference?
The terminology can be a little misleading. The minimally invasive approach is not as minimally invasive as the name suggests, and the open method is not as extensive as one might expect. In open surgery, an incision is made at the carpal tunnel. The band is then cut, the nerve and tendons are freed, and the wound is closed.
With the endoscopic approach, the incision is slightly smaller. A camera and a bladed instrument are inserted through it, allowing the band to be cut without fully opening the skin above it. Which technique is used also comes down to personal experience. Most seasoned surgeons have tried both methods and settled on whichever they find most effective.
Each approach has its advantages and drawbacks. With open surgery, the scar requires careful management, as it can harden over time. With the endoscopic method, there is a slightly higher rate of incomplete division of the band due to limited visibility, and the nerve cannot be directly freed at the same time.
In my view, a surgeon should use the technique they are most skilled at. The outcomes are ultimately much the same regardless.
Which method do you personally prefer?
I use the open technique.
Can the nerve fully recover after this kind of operation?
Yes, absolutely. It is a very rewarding operation, because patients often come to us in tremendous pain. Their hands are burning, their fingers keep falling asleep, and at night they can barely get any rest.
In fact, it is the one operation where I actually make a promise beforehand. I tell patients: "Tonight, you will sleep." And it delivers. The moment the nerve has enough space again, it is free and the pain disappears.
More caution is warranted when permanent numbness or reduced sensitivity is already present. In those cases, the nerve needs time to recover, and how well it does so depends on several factors: age, the individual's healing capacity, and how long the nerve has been compressed.
In such situations, I tell patients that things may not change right away. The nerve needs roughly a year and a half before we can gauge how far it has recovered. When surgery is performed in time, a full recovery is generally achievable.
Smartphone Thumb and Avocado Hand: Everyday Risks
What puts our hands at the greatest risk in everyday life?
Some factors are beyond our control. Genetic predisposition plays a major role in finger arthritis in particular. With overuse syndromes, however, our everyday habits are often the deciding factor. Typing, using a computer mouse, constantly being on our phones — all of it places considerable strain on the hands.
We might go to the gym once a week for our backs, but hardly anyone thinks to stretch their hands regularly. Most people only pay attention when symptoms appear — whether in the hand itself or elsewhere, such as the elbow, in the form of a tennis elbow.
What is smartphone thumb, and how can the symptoms be brought under control?
Smartphone thumb develops when the tendons become overloaded from constantly scrolling across the screen with the thumb. The first step is straightforward: spend less time on your phone. It also helps to change your hand position regularly. As with other overuse problems, repeatedly making the same movement in the same position — with just one finger, no less — is counterproductive.
And what is the so-called avocado hand?
It is an entirely preventable injury. The term came about because we were seeing a growing number of cut injuries to the palm caused by preparing avocados.
The injury typically occurs when removing the pit: many people halve the avocado, strike the knife into the hard pit, and try to lever it out. The knife can slip and drive straight into the hand holding the fruit. Because tendons, nerves, and blood vessels run through the hand in an extremely confined space, the resulting injuries can be serious.
My advice is simple: put the knife down and use a spoon to remove the pit. If that does not work, the avocado is not ripe enough anyway.
Finger Arthritis: What Options Are Available Today
You have said that nobody today has to end up with stiff fingers because of arthritis. How can that be prevented?
I may have gone out on a limb a little with that statement. But essentially it holds true, because we now have good surgical options available.
In the past, many women with finger arthritis were told by their orthopedic specialist that nothing could be done. Eventually the joints would simply stiffen — and with the small finger joints in particular, that can happen relatively quickly.
Today we have well-established prostheses available for the proximal interphalangeal joints, the knuckle joints, and the thumb that genuinely work.
When arthritis is causing pain and mobility is already reduced or early limitations are beginning to appear, surgery offers a real opportunity to prevent the fingers from stiffening.
Thumb basal joint arthritis is one of the most common degenerative conditions of the hand and affects women after menopause in particular. Why is that?
It comes down, in part, to the exceptional mobility of the thumb. You can see for yourself: we can move the thumb forward, backward, and sideways, wrap it around the other fingers, and perform an enormous variety of movements. In my view, it is the most important finger on the hand.
To make all of that possible, the thumb basal joint needs a particularly wide range of motion — and that wide range of motion leads to wear over time. In women after menopause, an additional factor comes into play: the ligaments become somewhat looser and hyaluronic acid is increasingly broken down, causing further deterioration in the joint.
That is why we see this form of arthritis so frequently in women. But it, too, can be treated very effectively today.
There is now a new generation of prostheses for the thumb basal joint that even some orthopedic specialists are not yet aware of. What has changed?
Prostheses for the thumb basal joint have been around for a very long time. However, the earlier models did not deliver good results. When I started out, they were still considered problematic — prone to dislocation and associated complications.
For a long time, we therefore primarily performed what is known as resection arthroplasty, which involves removing one of the two joint partners — a small carpal bone — thereby eliminating the source of friction.
It is a sound operation that works very well. Its main drawback, however, is the lengthy recovery. It takes a considerable amount of time before patients can move their hand normally again, are free of pain, and can return to their daily lives. That is a real issue today, when many people want to stay active well into old age and work for longer.
It is therefore all the more encouraging that prostheses have advanced considerably over the past ten to fifteen years. The newer models are designed along the lines of a hip joint prosthesis: they consist of three components, can be individually adapted, and fuse with the bone, while still allowing the full range of motion the thumb requires.
This has truly transformed our treatment options. There are still cases where a prosthesis is not appropriate — for example, when arthritis is also present in adjacent joints. Overall, however, the results are so good and patients return to everyday life so much more quickly that I now perform resection arthroplasty only rarely.
