Complex regional pain syndrome (CRPS), a disorder that is not yet understood by doctors, can cause severe pain to a limb following a trauma, including surgery. Some patients who undergo carpal tunnel release do develop CRPS I following the surgery. This brings about a concern if these patients require a second surgery for carpel tunnel, something that is not uncommon.
The authors of this study examined the relative risk of CRPS in patients who had developed CRPS once before following the surgery. They wanted to see if there were signs that may show them that this may happen.
Researchers recruited 34 patients who had experienced CRPS following carpal tunnel release and who had been successfully treated. To be eligible for the study, the patient had to have at least one of the following: hand numbness, weakness in the thumb, or any of the diagnostic signs for carpal tunnel syndrome. Each patient’s hand was examined with laser Doppler imaging a few days before surgery and then again between 19 to 22 days after surgery.
The patients were divided into two groups, depending in the test findings. During the doppler examination, the researchers watched for signs of sweating or temperature change in response to the patient taking a deep gasp of air and holding the breath to stimulate such a reaction. Patients who did not have a reaction were put into group 1 and those who did have a reaction, were put into group 2.
When looking at the findings after the second surgery, the researchers found that eight of 11 patients in group 1 had developed recurrent CRPS, while only three of the 23 patients in group 2 did. Each patient who did develop CRPS was successfully treated. The authors wrote, “We attribute this success to the timely diagnosis and treatment of this condition.” They conclude that CRPS can recur following hand surgery and that it may be able to identify those at highest risk of recurrence.