Carpal Tunnel Syndrome - James T. Mazzara, MD

Dr. Sechrest: Hello, I'm Dr. Randale Sechrest, your host for eOrthopod.TV. Today I have as my guest, Dr. Jim Mazzara. Dr. Mazzara did his medical school training at New York Medical College. He then went on to complete an orthopaedic residency at St. Luke Roosevelt Hospital, which is a teaching hospital affiliate of Columbia University. Good morning, Dr. Mazzara.

Dr. Mazzara: Good morning.

Dr. Sechrest: Dr. Mazzara, what I thought we would discuss now is a very common hand condition, and that's carpal tunnel syndrome. I think everybody has heard the term carpal tunnel syndrome. I'm not certain everybody knows what that means. We all have our ideas about what that means. But why don't you start by telling us what is carpal tunnel syndrome?

Dr. Mazzara: Carpal tunnel is pressure or swelling on or around the nerve in the wrist. The carpal tunnel is a small bony tunnel in the wrist. Three of the four sides of the tunnel are made of bone in the wrist and hand. Over the top of that tunnel is a ligament, it's called the transverse carpal ligament. In that little enclosed space of the carpal tunnel are 9 tendons and your median single nerve, and anything that causes any kind of pressure, swelling, or a compression of the nerve will cause symptoms in that nerve to manifest in the form of numbness or tingling or aching or weakness in the hand. Sometimes patients will actually get aching in the forearm and sometimes aching and pain up to the shoulder and neck in more advanced cases.

Dr. Sechrest: Okay. Now, we hear a lot about repetitive stress injuries. We hear a lot about why people get carpal tunnel syndrome. Tell me what your opinion is in terms of why we get this problem.

Dr. Mazzara: I think a lot of the studies will actually look at a lot of the conditions that contribute to carpal tunnel based on things we do, and many of these studies come back and say probably the greatest predisposing factor to developing carpal tunnel is probably genetics and being a female. Anatomically, the carpal tunnel may be smaller in females and in certain other adults who also get carpal tunnel, but at the same time, there might be other aggravating factors and conditions, like thyroid disease and rheumatoid arthritis, history of trauma or wrist fractures and pregnancy will also be associated with the swelling and fluid imbalance around the nerve that tends to squeeze the nerve. We also look at people who do things for a living that may cause repeated motion or repeated swelling and stress around the carpal tunnel. We know that people who do repetitive tasks in a factory, let's say, would do this back and forth wrist extension / flexion under some kind of force, are more likely to get carpal tunnel than somebody who sits in front of a keyboard for 6 or 7 hours a day. Now, we might say that somebody who does repetitive keyboarding might be predisposed to getting it, but the data doesn't seem to suggest that working at a keyboard causes carpal tunnel. It may aggravate carpal tunnel, but it doesn't necessarily cause it. There was a study done by the Mayo Clinic a number of years ago that actually looked at patients who worked in front of a keyboard, keyboarding for 7 hours a day, and they did not find at that time that there was a high correlation between keyboarding and the cause of carpal tunnel. So, while it might be an aggravating factor, it's not necessarily a cause. In addition, there are medications that may cause fluid imbalance and, as I said pregnancy, thyroid disease, rheumatoid arthritis, and diabetes will also contribute to the development of carpal tunnel.

Dr. Sechrest: I think the take home point there is that, if I hear you correctly, anything that causes pressure on the nerve in the carpal tunnel can cause the symptoms of carpal tunnel because, what we're really talking about is the pressure that's affecting the nerve that ends up in weakness, numbness, and tingling in the hand for the most part.

Dr. Mazzara: That's correct.

Dr. Sechrest: Symptoms. Let's go over the symptoms. We all see patients in our office that come in during the day that say, "At night I'm getting numbness in my hands. I'm waking up, my whole hand is numb and I'm not certain what's happening." Sometimes, they'll come in and say, "I think I've got carpal tunnel", and we try to lead them through a series of questions to try to get to that point. Talk to me a little bit about the symptoms that patients are going to feel and how they may be able to determine whether it's carpal tunnel or some other problem.

Dr. Mazzara: Well, patients who have numbness and tingling at night or aching in the hand and wake up and shake the hand as if to wake it up will very frequently report numbness in the entire hand. When you ask those people further questions, and if you ask them to pay attention, what they eventually recognize is that the whole hand may feel numb. When they touch the little finger, the little finger tends not to be involved. The median nerve supplies the sensation to the thumb, the index, the middle, and half of the ring finger, and so those people will come into the office, and on sensory testing, if they're not normal, their diminished sensation may be in these fingers without any involvement of the little finger. They may also have aching in the hand. They may have aching in the arm sometimes as far as the neck and shoulder and, in advanced cases, they may also have some weakness in their ability to pinch or to use their thumb. The motor branch of the median nerve goes to the muscle in the base of the thumb here, and when you look at the base of the thumb, there should be a nice round full muscle there. When it's indented or atrophied, that's generally an indicator of some kind of advanced nerve injury. When you examine patients and listen to people, you want to make sure you've examined the nerve at every other level, so you want to make sure that they don't have some kind of nerve injury in the upper forearm or even as high as the neck.

Dr. Sechrest: When you start examining these patients, what are you doing? What do you go through in terms of your exam?

Dr. Mazzara: Well, once I've taken a thorough history, I look at their hands. I inspect their hands for atrophy. I want to see if they have arthritis, if they have any atrophy or wasting of any of the muscles in their hands, and then I check for range-of-motion. Once I've checked their range-of-motion, then I'll do a couple of other little tests that actually are designed to irritate or provoke symptoms in the patient. So I might tap the carpal tunnel on the base of the wrist and if patients experience numbness or tingling either here where I'm tapping them or up to the fingers, that's an indication that the nerve may be irritated. I might ask them to flex the wrist, though studies have shown that if you flex your wrist, almost anybody who flexes their wrist for long enough, will eventually experience a little numbness or tingling. So, that's not as reliable an indicator as we would like it to be. One test that seems to be a little bit more reliable is a test called the carpal tunnel compression test which is actually a test where the examiner just takes their thumb pushes over the carpal tunnel at the level of the area of compression, and if the fingers start to go numb or tingle within 30 seconds or even a minute, those people are generally found to have carpal tunnel syndrome that can later be proven by means of an eventual nerve conduction test.

Dr. Sechrest: Now, once you're through with the physical examination and you're suspecting carpal tunnel, what do you do in terms of tests? Is this something that you would recommend any type of imaging studies such as an x-ray or an MRI scan, or are there other tests you might look for?

Dr. Mazzara: Sometimes I'll do an x-ray of the wrist in the office, but I don't necessarily do a nerve conduction test initially unless, when I examine those patients, they have atrophy or when I test their sensation they clearly have diminished sensation in the distribution of the median nerve. If, when I examine them, they have atrophy of the hand indicating nerve injury, or when I test their sensation of their index and their middle finger and it's different than the sensation on the other side or the sensation of the little finger on the same hand, those people who have sensory deficits in the distribution of the median nerve get an early nerve test; because to treat them nonoperatively when they probably have more advanced disease doesn't really make a lot of sense. I want to give them the information from the very beginning. If they're at the mildest stage of carpal tunnel and their sensation is intact and they have no motor weakness of their hand and no atrophy, we'll treat them conservatively at first, and eventually if they fail to respond to conservative treatment then we'll do some nerve testing. I don't usually need an MRI of the wrist unless I think there's a mass compressing the carpal tunnel. If there's something unusual in the plain x-ray, it might prompt me to do something else. You can always see evidence of previous trauma or arthritis in a wrist x-ray and that's an important factor in helping determine one of the potential causes for carpal tunnel.

Dr. Sechrest: So you're not really looking for an answer when you do the x-ray, but you're looking to rule out anything that might explain why they're having carpal tunnel.

Dr. Mazzara: I want to see if there's anything anatomically causing pressure or narrowing of the carpal tunnel, and if there is, we need to know about that from the very beginning.

Dr. Sechrest: As you begin your conservative treatment what do you think that patients respond to best? What do you start with in terms of conservative treatment?

Dr. Mazzara: It's generally going to be activity modification so, if they tell me that they're symptoms are aggravated at work I'll ask them to do an ergonomic evaluation of their workplace and just do things a little differently. You don't have to stop it entirely, just modify how you do that. I also recommend that they get a wrist immobilizer that they wear at night only. The median nerve and any nerve needs to have the ability to slide and move back and forth so as you bend your hand back and forth, the nerve needs to be able to move. There's normal excursion to every nerve just like there is every tendon. At night, however, when we tend to sleep we bend the wrist, and the use of a wrist immobilizer at night prevents us from bending the wrist, keeping the wrist like this. This permits adequate circulation to the nerve and tends to diminish the impaired circulation that results from bending the wrist, improves function, people sleep better, feel better; that, in combination with anti-inflammatories can be very, very helpful.

Dr. Sechrest: Now several years ago, there was some significant interest in a set of exercises that people could do, either as a preventative strategy, or even with mild cases of carpal tunnel, that the physical therapist really felt helped the symptoms of carpal tunnel. What's your position on that? How you found exercise to be beneficial in people who were suffering the symptoms of carpal tunnel?

Dr. Mazzara: I've not really found a consistently reliable way for people to get any real relief from their carpal tunnel. The only thing that I would suggest is that they change how they do their activities that seem to aggravate their symptoms, but exercise in therapy doesn't seem to be very beneficial. People will commonly refer to other studies that have looked at different types of treatments. Vitamin supplements are only beneficial if you have a vitamin deficiency and most people who have carpal tunnel don't have a B-12 deficiency and therefore aren't going to really benefit from a Vitamin B supplement. Other kinds of treatments people have sometimes advocated laser treatment. I don't think there's any good scientific data that says that works. There are other less conventional treatments which also don't seem to work.

Dr. Sechrest: What about injections? Do you find injections useful for the treatment, or maybe the diagnosis, of carpal tunnel syndrome?

Dr. Mazzara: I think if somebody has symptoms of carpal tunnel and may have a negative nerve test, an injection may be very beneficial. Most of those patients will come back within a year and have a recurrence of their symptoms. Cortisone injections into the carpal tunnel are only beneficial for milder forms of the carpal tunnel. It's not a cure by any means, and a lot of those people get their symptoms back within a year. So, if it's moderate or advanced carpal tunnel, injections have no role. If you are not sure, if somebody presents as if they have carpal tunnel but they have a negative nerve test, an injection is a great way to rule out some other cause of a nerve compression or nerve injury, because, if you give them an injection in the carpal tunnel and they get better, even in the face of a negative nerve test, they have carpal tunnel. The problem is when you eventually recommend surgery for those patients, if they come to surgery, the eventual outcome of that surgery is not as reliable as if they had a clearly positive nerve test and a clearly identifiable diagnosis of carpal tunnel. Many of them get better, yes, but the success rate is not quite as high.

Dr. Sechrest: The one place that I found it useful is in that patient, and I use to take care of a lot of loggers who were running chainsaws. The problem is, when you're a logger, you have this window of opportunity in the spring called breakup so they had 3 months off, so they never wanted to have surgery in the fall. So sometimes I would find that even if they knew they were going to have surgery, we could give them an injection to get them through until they were off for a period of time and then they had their surgery. So it was useful to delay surgery.

Dr. Mazzara: Well, with the work-related activities like the use of a chainsaw, those kinds of tools, has been associated with the causation of carpal tunnel syndrome.

Dr. Sechrest: When you finally recommend surgery to a patient, what are you using as guides to determine when to make that recommendation?

Dr. Mazzara: Well, if somebody has gone through conservative treatment, they have mild to moderate carpal tunnel, they continue to have symptoms, and they're not getting better, they become a candidate for surgery. Somebody who has got more advanced carpal tunnel, I would recommend they have surgery even if they've not had conservative treatment, because not to recommend surgery in the face of more advanced carpal tunnel syndrome is going to allow that nerve to worsen over time, then if there's permanent nerve damage, it's guaranteed to get worse. When you treat those people with a carpal tunnel release, what you have to tell them is that if all goes well, and the vast majority of the time everything goes perfectly, you still may not come back with a normal hand. You may still have some weakness and numbness, and the reason that may occur is simply because the nerve is damaged, but then has an opportunity to recover from that point forward. But those people may come back and the aching and tingling and the symptoms that would wake them up at night may be vastly improved, but their fingers may still be numb and their hand may still be a little bit weak. When patients have milder or moderate carpal tunnel, if they've had conservative treatment and they've not responded, those become excellent candidates to get a great result from surgery because there's no permanent nerve damage. Just go in, release the nerve, decompress it, very quick recovery for those people. It's a procedure that I think is very, very successful in the vast majority of patients.

Dr. Sechrest: Now, let me paraphrase this and let me see if we're on the same page. What you're feeling is, is that you have evidence that there is permanent nerve damage occurring, that that nerve is not intermittently compressed and going back to normal at certain times during the day, then that's the person you're going to say, "The longer you wait, the more the risk that you'll never get full recovery."

Dr. Mazzara: Absolutely.

Dr. Sechrest: And that is either because you're seeing numbness that's there constantly, you're seeing muscle wasting or muscle weakness, or you're seeing something on the nerve conduction velocity test that you're doing that tells you that this nerve is undergoing permanent damage.

Dr. Mazzara: That's absolutely correct.

Dr. Sechrest: And in that case, you would say, "You're better off having surgery than simply putting this off."

Dr. Mazzara: Right. I would not recommend that a patient have splinting or anti-inflammatories. I would think that's a waste of time, and I think they'll come back and they will not be any better.

Dr. Sechrest: Okay. When you start to recommend surgery, how is this patient going to prepare? I'm assuming that this is an outpatient procedure and it's done, not in the office I'm assuming, but in the surgery center?

Dr. Mazzara: No, we do this in the operating room. It's an outpatient facility attached to the operating room. Patients come in, it's a 10 minute procedure, they get a quick general anesthesia, we prep and drape the hand, we make a small incision in the base of the palm right over the carpal tunnel, and we go down to the area where the ligament is, and on one side of the ligament, we make a small incision in the ligament, and then we take a little surgical scissor and release the ligament to both ends. We want to make sure that the whole carpal tunnel is released, and then I inspect the nerve, and we free up the nerve from any scar tissue that may be there. In general, these nerves are adherent and stuck on the ligament and, taking a little surgical scissor and mobilizing the nerve and freeing it up are very, very helpful. I then take a little 2 millimeter piece of the ligament, I excise that, and that seems to give the nerve a little bit more room. If that ligament ever heals back, and it can certainly heal back and re-attach, those patients over time will develop carpal tunnel in years to come. Potentially, there's a rate of recurrence for any kind of carpal tunnel. I go in and I take a little piece of that ligament out and it seems to make a difference.

Dr. Sechrest: Well, you know, patients always ask me, well what happens to that ligament? You cut it, why is it there? What's going to happen to my nerve if you cut this ligament? What do you tell patients?

Dr. Mazzara: Patients don't generally notice any functional difference after the surgery. They notice that their hand feels better and functions better. So, yes, the ligament has a function, it puts extra tension on the tendon so you get more strength. Any strength deficit that anybody would notice after carpal tunnel release is minimal at best. Most patients never really notice that.

Dr. Sechrest: Tell us a little bit about the recovery period? The wound is sutured up . . .

Dr. Mazzara: I close the skin with nylon stitches. 48 hours after surgery, I tell the patients, "Take off the dressing and use your hand as tolerated. Put a band-aid on the incision. Keep it clean and dry and I'll see you in 10 days. Call me if there's a problem." 10 days later they come in, we take the stitches out. They are nice to their incision for a couple more days, and then they can go back and do almost anything they need to. Return to work is going to depend on what patients do, but I release patients to unrestricted at about 3 weeks. One of the things that we sometimes see after surgery is what's called the flare reaction. That's a little inflammatory response in the incision where the incision just feels a little bit sore, almost like you scraped your palm on the ground. If that's going to occur, that doesn't occur initially, that might occur 4 or 5 weeks after surgery and desensitizing that with a little hydrocortisone cream or use as tolerated, sometimes a little therapy can be helpful. Most patients who have carpal tunnel in my practice really don't need physical therapy after the surgery.

Dr. Sechrest: What do you think is causing that flare?

Dr. Mazzara: I think it's a part of the healing process. The incision always looks a little bit red, inflamed, and irritated, and in fact it is. But there are inflammatory cells in the area that are required to heal the skin, heal the tissue, and there's a certainly very high density of nerve endings in the hand that make it a little bit more sensitive there than if you had an incision or laceration someplace else in your body.

Dr. Sechrest: Yeah, I think patients don't understand who sensitive the soles of our feet and the palms of our hands are, and they do not respond to making incisions as well as other places.

Dr. Mazzara: But it's temporary, and just supporting those patients and helping them understand that it's not unusual. It may not occur in most patients. I would say I see it in 20-25% of people. Postoperatively, it always goes away. It takes a little while and if they are concerned about it, they come back and let me see it.

Dr. Sechrest: Now, long term. You mentioned that there is a rate of recurrence. So if that ligament re-attaches, patients can develop carpal tunnel syndrome again, so the same symptoms. How frequent is that?

Dr. Mazzara: That's actually very uncommon. If it occurs, it generally occurs many years after the original procedure.

Dr. Sechrest: Is there something you could do about it? Is this something that you can go back?

Dr. Mazzara: Yeah, absolutely. You can have another carpal tunnel release and that generally works as well as the first one did, and you may get another many, many years of good symptom relief after that one as well.

Dr. Sechrest: Well, let's talk a little bit about things we don't like to discuss and that's what can go wrong with carpal tunnel syndrome or carpal tunnel surgery. It's interesting, I used to tell colleagues that the worst, the most risky operation, is the one that's the most minimal because everybody is expecting perfection.

Dr. Mazzara: That's right.

Dr. Sechrest: So carpal tunnel falls in that category because you and I don't expect to have complications in carpal tunnel surgery.

Dr. Mazzara: Well, I would tell you that patients who have the surgery can have potential complications like nerve damage, bleeding, infection are very, very uncommon. It can happen, as we discuss with any patient, any time we operate on or near a nerve, there's always potential for that nerve to become injured in one way or another. There's always that risk of bleeding or swelling in or on the carpal tunnel that can cause short-term recurrence symptoms. Again, very. very uncommon, generally temporary, not a permanent condition, and then sensitivity of the incision. So sensitivity may create a bit of concern after the fact, that is really not a complication, it's part of the healing process, and eventually goes away. Some people will have what's called "pillar pain". Pillar pain is a little pain on either side of the incision and the thought is that, once you've released the ligament, the ligament ends retract a little bit; that irritates the nerves in part of that ligament, and that generally gets better and goes away. That I find is not a major problem.

Dr. Sechrest: Any other recommendations you would have for patients who are looking at treatment options for carpal tunnel syndrome? Anything we haven't discussed?

Dr. Mazzara: Well, I think patients who have carpal tunnel or think they have carpal tunnel need to understand that it is, to a certain extent, a time sensitive diagnosis. It's not an emergency, but at the same time, it's not the kind of condition you want to wait 2 and 3 years to treat. Over a period of time, the nerve is susceptible to progressive and eventually permanent damage, and I think once you think you have carpal tunnel, you owe it to yourself, and certainly to your median nerve, to get that investigated. Even if you end up with very simple conservative treatment and a splint and you get better, that's better off than allowing that nerve to remain under pressure and eventually develop permanent problems.

Dr. Sechrest: Well, thank you. I think that's excellent advice for patients with symptoms that are compatible with carpal tunnel syndrome, and may give them a lot of information that they can go seek out treatment. Thank you very much.

Dr. Mazzara: Thank you.

Dr. Sechrest: Thank you very much. Thanks for watching today. If you have questions about the topic that we discussed today, or any orthopaedic topic, be sure to visit eOrthopod.com. If you're an orthopaedic surgeon or healthcare provider interested in participating as a guest on eOrthopod TV, you'll also find instructions on how to apply to become a guest on eOrthopod TV. Thanks for watching.