J. Brett Gentry, M.D. • Dennis A. Ice, M.D. • Wayne S. Paullus Jr., M.D.

806-353-6400 • 800-658-6636 • 1000 S. Coulter • Amarillo, Texas

Single-portal Endoscopic carpal tunnel releasecompared with open release.

Every year over 200,000 people in the US undergo surgeries for carpal tunnel syndrome, rendering them among the most common surgical procedures performed on the hand. In various trials, 70% to 90% of patients who underwent surgery were free of nighttime pain afterward.

Candidates for Surgery

Although evidence strongly suggests that surgery is more effective than conservative approaches (at least in patients with moderate to severe CTS), the decision about whether and when to have surgery to correct CTS is a troubling one for patients. Electrodiagnostic and other tests used to confirm the presence of CTS are not very useful in determining the best candidates for surgery. For example, results suggesting severe CTS may not relate at all to surgical success or the lack of it.

In general, patients with the following findings are less likely to respond to conservative therapy and, therefore, might benefit from surgery:

  • Older than 50 years.
  • Symptoms lasting 10 months or longer.
  • Continual numbness.
  • The muscles in the base of the palm have begun to atrophy (shrink)
  • Symptoms occur within 30 seconds during a Phalen's test.

According to a 2002 study, if none of these factors are present, conservative therapies (splinting and anti-inflammatory agents) are effective in two thirds of patients. However, the conservative approach was ineffective in 60% of patients if only one of these factors were present, in 83% with only two of them, and in virtually all patients who had three or more.

Surgery does not cure all patients, and because it permanently cuts the carpal ligament, some wrist strength is often lost. A number of experts believe that release surgery is performed too often. They recommend aggressive conservative treatment (e.g., splints, anti-inflammatory agents, and physical therapy) before choosing the more invasive option.

Nevertheless, other experts argue that CTS is often progressive and will worsen over time without surgery. Furthermore, evidence now strongly demonstrates that surgery is superior to splints and conservative measures for the relief of pain.

Open Release Surgery. Traditionally, surgery for CTS entails an open surgical procedure performed in an outpatient facility. The surgery is straightforward:

  • A local anesthetic is injected either into the wrist and hand or higher up the arm. This injection can be very painful for some people. Applying an anesthetic cream before the injection can reduce the pain.
  • The surgeon makes a two-inch incision in the palm. In some cases, the incision must be extended into the forearm.
  • The surgeon makes further incisions in the muscles of the hand until the carpal ligament is visible.
  • The carpal ligament is then cut free from the underlying median nerve. The ligament is literally released and, therefore, the pressure on the median nerve is relieved. Sometimes the lining of nearby tendons is also pared (called flexor tenosynovectomy), but one study showed no benefits from this additional step.

Endoscopy. Endoscopy for carpal tunnel syndrome is a less invasive procedure than standard open release.

Briefly, the procedure is as follows:

  • One or two 1/2-inch incisions are made in the wrist and palm, and one or two endoscopes (pencil-thin tubes) are inserted.
  • A tiny camera and a knife are inserted through the lighted tubes.
  • While observing the underside of the carpal ligament on a screen, the surgeon cuts the ligament to free the compressed median nerve.

BACKGROUND: Endoscopic carpal tunnel release has been demonstrated to reduce recovery time, although previous studies have raised concerns about an increased rate of complications. The purpose of this prospective, randomized study was to compare open carpal tunnel release with single-portal endoscopic carpal tunnel release. METHODS: A prospective, randomized, multicenter center study was performed on 192 hands in 147 patients. The open method was performed in ninety-five hands in seventy-two patients, and the endoscopic method was performed in ninety-seven hands in seventy-five patients. All of the patients had clinical signs or symptoms and electrodiagnostic findings consistent with carpal tunnel syndrome and had not responded to, or had refused, nonoperative management. Follow-up evaluations with use of validated outcome instruments and quantitative measurements of grip strength, pinch strength, and hand dexterity were performed at two, four, eight, twelve, twenty-six, and fifty-two weeks after the surgery. Complications were identified. The cost of the procedures and the time until return to work were recorded and compared between the groups. RESULTS: During the first three months after surgery, the patients treated with the endoscopic method had better Carpal Tunnel Syndrome Symptom Severity Scores, better Carpal Tunnel Syndrome Functional Status Scores, and better subjective satisfaction scores. During the first three months after surgery, they also had significantly (p < 0.05) greater grip strength, pinch strength, and hand dexterity. The open technique resulted in greater scar tenderness during the first three months after surgery as well as a longer time until the patients could return to work (median, thirty-eight days compared with eighteen days after the endoscopic release). No technical problems with respect to nerve, tendon, or artery injuries were noted in either group. There was no significant difference in the rate of complications or the cost of surgery between the two groups.

CONCLUSION: Good clinical outcomes and patient satisfaction are achieved more quickly when the endoscopic method of carpal tunnel release is used. Single-portal endoscopic surgery is a safe and effective method of treating carpal tunnel syndrome.