乌鸦传媒

Surgery was more effective than splinting for carpal tunnel syndrome, but improvements in function and symptoms were only modestly better with the invasive treatment, a new study found.

A year after treatment, surgical patients saw a 0.40 point average improvement in function on a 5-point scale (95% CI 0.11 to 0.70, P=0.0081) and a 0.34 point improvement in symptoms (95% CI 0.02 to 0.65, P=0.0357) compared with patients who received nonsurgical treatment, according a report in the Sept. 26 issue of The Lancet.

"Both surgical and nonsurgical groups improved over 12 months, but patients assigned to surgery had significantly greater relief of symptoms and improvement in hand function by six months that persisted at one year than patients assigned to nonsurgical treatment," Jeffrey G. Jarvik, of Harborview Medical Center in Seattle, and colleagues wrote.

"However, the magnitude of these differences was small and of moderate clinical relevance."

Carpal tunnel syndrome, in which the median nerve running from the forearm into the hand becomes pressed or squeezed at the wrist, can result in pain, weakness, and numbness in the hand and wrist and radiating up the arm.

Three of every 10,000 workers lost time from work because of carpal tunnel syndrome in 1998 and half of these workers missed more than 10 days of work, according to the National Institute of Neurological Disorders and Stroke.

The average lifetime cost of carpal tunnel syndrome is estimated to be about $30,000 for each injured worker.

An early review found that surgical techniques worked better than nonsurgical treatments, but concluded that more research was needed, especially for patients with mild symptoms.

Furthermore, only four of the previous trials were randomized, and the earliest study had serious methodological problems, the authors wrote.

Jarvik and colleagues wanted more evidence on the relative merits of surgery and noninvasive treatments. They also investigated whether wrist MRI could be used to predict which treatment would work best for a given patient.

The researchers randomly assigned 116 patients from seven medical centers in Washington and one in New Hampshire to receive either surgical or nonsurgical treatment. At randomization, the patients were scheduled to receive an MRI of their median nerve.

Patients in the surgical group were assigned to open or endoscopic decompression to relieve pressure on the median nerve, depending on the surgeon's preference.

Those in the nonsurgical technique were offered 200 milligram ibuprofen three times a day and scheduled to see a hand therapist for six customized hand-therapy sessions over six weeks.

The hand therapy sessions focused on ligament stretching, tendon gliding, and review of splint use, during which the patients were encouraged to use their splints at night and as much as possible during the day. If patients in this group did not show adequate improvement within six weeks, they were offered therapeutic ultrasound, consisting of up to 12 sessions over the course of six weeks.

The researchers followed the patients for a year after randomization, using the Carpal Tunnel Syndrome Assessment Questionnaire (CTSAQ) to assess changes in function and symptoms. During the study, no adverse events or surgical complications occurred.

"We show that surgery improves symptoms of patients with carpal tunnel syndrome without denervation more than does a well-defined nonsurgical treatment," the authors wrote.

They also found that 90% of patients with normal to moderately abnormal median nerve signals on MRI had successful outcomes with surgery, while only 47% in this group had successful outcomes with nonsurgical care (RR 1.91, 95% CI 1.17 to 3.13, P=0.04).

In contrast, only 45% of patients with severely abnormal nerve signal benefited from surgery (RR 0.71, CI 0.33 to 1.57) while 64% saw improvement with the nonsurgical treatment.

"These findings should not be interpreted as suggesting that patients with abnormal nerve signal should not have surgery, but rather that the outcomes of surgery in this group might be less favourable than in those with normal nerve signal," the authors wrote.

The authors noted that only half of the patients underwent MRI, which limited the power of the study. Other limitations included nonstandardized surgical methods (both open and endoscopic surgery) and recruitment of about half of the participants from a Veterans Affairs facility, which may limit applicability to the general population.

In an accompanying editorial, Isam Atroshi, MD, PhD, and Christina Gummesson, PT, PhD, of Lund University in Sweden, write that the findings are important because nonsurgical patients were offered and typically received several of the noninvasive treatments available.

Although they acknowledge that the study provides additional evidence that surgery results in better outcomes for some carpal tunnel patients, they cautioned that this does not mean that all patients with moderately severe carpal tunnel syndrome should undergo surgery as a first line of treatment.

For patients whose symptom duration is short and the diagnosis uncertain, they wrote, nonsurgical treatment might avoid some of the negative aspects of surgery, including potential for complications, long-term palm pain, and longer disability.

"Patients with carpal tunnel syndrome who do not have satisfactory improvement with nonsurgical treatment should be offered surgery," they concluded

They also wrote that the utility of MRI in managing carpal tunnel remains unclear and that "the high rate of normal MRI suggests it would not be a useful diagnostic test. Although potentially interesting, more research is needed before a role for MRI in carpal tunnel syndrome can be defined."

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