Carpal tunnel syndrome (CTS) is marked by numbness, weakness, and pain in the wrist, hand and arm, and occurs when the median nerve, which runs from the forearm to the base of the palm, becomes compressed.
Despite the prevalence of CTS and its considerable economic impact – in terms of both worker absenteeism and compensation claims – there is no universally accepted therapy. Mild cases are usually left untreated and moderate cases may be treated with local injections of corticosteroids, if patients fail to respond to splinting and anti-inflammatory drugs like ibuprofen.
In severe cases, with the threat of permanent loss of sensation, the preferred treatment is surgery. Surgery, however, is often recommended to patients before trying less invasive and less expensive treatments. The results of a recent clinical trial now suggest that local steroid injection is just as effective as surgery for the long-term symptomatic relief of CTS – for a year, at least – and more effective over the short term.
The research effort focused on 101 patients. Of the total wrists evaluated, 80 were randomly assigned to the standard surgical procedure, decompression of the median nerve, and the remaining 83 wrists were treated with local steroid injection. 14 days after the initial treatment, 69 of the wrists that had been treated with steroids received a second local injection. Researchers then assessed the symptoms of both groups at three, six, and 12 months, using visual analog scale scores to measure improvement.
At the three-month mark, 94% of the wrists in the injection group achieved significant improvement – a response of 20% or better – for nocturnal symptoms, compared with 75% of wrists in the surgery group. At the six-month mark, 85.5% of wrists in the injection group achieved this response, compared with 76.3% in the surgery group. At the 12-month mark, 69.9% of the wrists in the injection group achieved the response, compared with 70% in the surgery group.
Throughout follow-up, results for two other symptoms measured – daily pain in the wrist area and self-perceived functional impairment – were similar.
“This is the first randomized controlled clinical trial comparing the two most common therapies for CTS,” noted one of the study’s authors, Dr Domingo Ly-Pen. “Our findings suggest that both local steroid injections and surgical decompression are highly effective in alleviating the symptoms of primary CTS at 12 months of follow-up. Nevertheless, local injection seems superior to surgery in the short term.”
In addition, more patients whose wrists were randomly assigned to surgery rejected the treatment than did those whose wrists were assigned to injection.
Surgery, the study authors stated, may still be the best course in severe cases of CTS for avoiding loss of sensation and improving function. This study, however, has important implications for the effective early treatment of CTS.