“Just the facts, Ma’m”
Sergeant Joe Friday from the 1960’s TV series “Dragnet”
Carpal tunnel syndrome is very common, and it seems like the diagnosis of the problem is increasing each year. Naturally this begs the question as to whether or not something can be done to prevent the problem. A lot of study has gone into this issue, but it turns out that a lot of what we thought we knew about the causes of carpal tunnel syndrome hasn’t stood up to statistical analysis.
In the 80’s and 90’s there were a large number of articles associating carpal tunnel syndrome with certain activities including repetitive motion of the hands, computer keyboard use and exposure to excessive vibration. This certainly spawned a cottage industry of workplace modification. The most well known example of this was probably the ergonomic keyboard. There was quite a bit of debate among hand surgeons about these claims, many of whom doubted the quality and the validity of the medical studies that seemed to show a correlation between specific activities and carpal tunnel syndrome. On the other hand there were several very prominent hand surgeons who vigorously defended the correlations shown in the published studies. In fact I remember one year at the annual national meeting of hand surgeons we were treated to a lively Point/Counterpoint style debate between two prominent hand surgeons about whether or not work activities caused carpal tunnel syndrome.
Most of that changed in 2007, when a very well designed study was published in the Journal of Hand Surgery, the main source of up to date medical information in our field. A group from the Massachusetts General Hospital in Boston led by Dr. David Ring, a well respected surgeon, reviewed 117 previously published articles and subjected the articles to a well defined statistical analysis to see if the data in the articles supported their conclusions. They found that the cause of carpal tunnel syndrome was largely genetic (you’re born with a predisposition to develop it), structural (it’s the way your body is built) and biological (certain health problems can cause it). They found that factors such as repetitive hand use and other occupational factors played a minor and more debatable role. This data tended to confirm what many hand surgeons, myself included, thought was actually the case. Most hand surgeons are now reluctant to link work activities with carpal tunnel syndrome. However I can assure you that the idea that keyboard and repetitive hand use causes carpal tunnel syndrome is imbedded in the minds of most people and they are quite surprised when I inform them of the findings of this study.
There are certain health conditions which are associated with carpal tunnel syndrome. The two most common are diabetes and hypothyroidism (low thyroid function). I often see both these conditions together in patients with carpal tunnel syndrome. People with chronic kidney disease and high blood pressure are also susceptible to carpal tunnel syndrome. People with rheumatoid arthritis are another group who tend to get carpal tunnel syndrome as well. I will occasionally see someone with carpal tunnel syndrome after a fracture or dislocation of the wrist, sometimes right after the injury but other times showing up weeks or months later.
So can you prevent carpal tunnel syndrome? Probably not. But if you are predisposed to developing the problem and find your hand going numb after certain activities then it makes sense to try and moderate or change the activity. If your hand goes numb while using a keyboard, then by all means try out an ergonomic keyboard. If you have diabetes or hypothyroidism it helps to keep those conditions under control with the help of your primary care physician. By taking common sense precautions you may not be able to prevent the problem, but you can certainly moderate the effects and prevent worse problems down the road.
In my next post I’ll discuss the thought processes I use to diagnose carpal tunnel syndrome. Hopefully this will help you understand what I do and what I’m looking for when I’m in the exam room with the patient.