Carpal Tunnel Syndrome
This is the most common peripheral nerve entrapment syndrome. This occurs when the median nerve is compressed by a ligament in the wrist. It generally causes pain and numbness in the thumb, index, and middle fingers. Often these symptoms are worse at night.
Treatment generally begins with avoiding aggravating or causative activities, such as using repetitive motions, use of keyboards, use of jackhammers, etc. Wrist splinting is typically the next step. Patients who still do not improve are offered decompressive surgery.
There are a variety of techniques in use to perform median nerve decompression at the wrist in patients who have carpal tunnel syndrome. One of the most popular is a mini-open technique in which the nerve is decompressed under direct vision through an incision that is an inch or less in length. Advantages of this procedure are its relative ease to perform, good visibility of the relevant anatomy to avoid damaging nerve branches, and low complication rate. The incision does require a few weeks to heal, however.
Figure 1. Mini-open incision used to treat carpal tunnel syndrome.
Figure 2. Intraoperative, highly magnified view of the median nerve (N) following decompression. The cut edges of the transverse carpal ligament are marked with asterisks.
Endoscopic carpal tunnel release uses either one or two tiny incisions through which a camera and a cutting tool are placed to perform the carpal tunnel surgery. Patients generally have less postoperative discomfort and are able to return to work more quickly compared to patients who undergo a mini-open procedure. The risk of injury to the median nerve and its branches is higher, however, in the endoscopic procedures. Additionally, due to the risk of nerve trauma, endoscopic procedures should npot be used in diabetic patients, as their nerves are less able to tolerate injury.
Figure 3. Endoscopic carpal tunnel release. Pictured in the inset is a magnified view of the special knife blade that is used to divide the transverse carpal ligament during endoscopic carpal tunnel release.