The safety and cost of repeated corticosteroid injections for carpal tunnel syndrome.

We studied the safety and cost of repeated local steroid injections for carpal tunnel syndrome. Medical records of patients treated by injection between 2016-2017 were retrospectively reviewed for 5 years. Two-hundred and twenty-one patients were included. The number of injections, the reason for surgery and any complications were recorded. A regression analysis was done for predictors of carpal tunnel release. The costs of the treatments were calculated. The mean number of injections was 2.3 (SD2.3; range 1-26). Two patients reported severe pain after the first injection. Thirty per cent of wrists proceeded to carpal tunnel release. Persistent and worsening symptoms were the main reasons for surgery. No intraoperative complications were noted. Patients who underwent release had a longer duration of symptoms and a higher percentage of thenar atrophy. The acquisition of nerve conduction studies was the only significant predictor for release. Cost analysis revealed that giving up to four injections before surgery reduced overall cost. Repeated injections were found to be safe in the treatment of carpal tunnel syndrome and did not affect the morbidity of subsequent release.Level of evidence: III.