The long-term follow-up of treatment with corticosteroid injections in patients with carpal tunnel syndrome. When are multiple injections indicated?

The objective of this prospective study was to investigate the long-term effect of one or more local corticosteroid injections in patients with carpal tunnel syndrome and whether a good response can be predicted. Follow-up visits took place at 3 weeks, 6 months, and 1 year after the first corticosteroid injection. Thirty of the 120 patients (25%) had a good outcome with a single injection, 11 additional patients (9%) needed a second injection, and five patients (4%) needed a third injection to reach a good outcome after 1 year. Of patients with an initial good treatment response, 28 (52%) had a good outcome after 1 year compared with 18 (27 %) who had an initially moderate or no response to treatment. One-third of patients with carpal tunnel syndrome had a long-term beneficial effect from corticosteroid injection, especially when they had a good initial response.