Key messages
Corticosteroid injection into the wrist probably improves symptoms of carpal tunnel syndrome (compression of a nerve in the wrist) and function of the hand for up to six months. Quality of life assessments, and tests of nerve conduction measured up to three months after injection, may also improve. Corticosteroid injection may reduce the need for surgery, assessed at one-year follow-up. Side effects appear to be rare. However, spontaneous improvement without treatment can occur in up to a third of people.
What is carpal tunnel syndrome?
Carpal tunnel syndrome is very common worldwide, affects people's quality of life and has significant financial costs for health systems. Symptoms occur when the median nerve in the wrist becomes 'irritated', which causes pain, tingling, numbness, and sometimes weakness and loss of function, mainly in the hand and fingers.
How is carpal tunnel syndrome treated?
Corticosteroids are medicines that reduce inflammation and swelling. Corticosteroid injections into the carpal tunnel (a narrow passageway surrounded by bones and ligaments on the palm side of the hand) tends to be used for mild or moderate symptoms and is much cheaper than surgery, but its effectiveness and how long any effects last are disputed.
What did we want to do?
We wanted to find out if local corticosteroid ('steroid') injection into the carpal tunnel at the wrist benefits people with carpal tunnel syndrome. The review authors collected and analysed all relevant studies to answer this question and found 14.
What did we do?
We searched medical databases for studies assessing the effects of local corticosteroid injections on symptoms and function of the hands and on improvements in electrical tests for nerve damage (called nerve conduction studies) up to six months after injection. We also looked at requirement for surgery, quality of life and side effects for up to 12 months.
What did we find?
We found nine studies involving 639 people conducted in hospital-based clinics across North America, Europe, and the Middle East. The studies excluded people with underlying conditions that often occur with carpal tunnel syndrome, such as arthritis and diabetes, and all participants had 'mild' or 'moderate' disease at the carpal tunnel.
Local corticosteroid injection probably improves symptoms and function of the hand at up to three months. Local corticosteroid injection probably improves nerve conduction. Quality of life at up to three months may improve and there may be a reduced need for surgery at one year. Serious complication rates were very low but only 66% of the studies reported them.
What are the limitations of the evidence?
Corticosteroid injections might work better or worse in people with more severe disease or with other conditions such as diabetes. We cannot say because those people typically were not included in the studies.
How up to date is this review?
The review authors searched for studies that had been published up to 26 May 2022.