Corticosteroid injection for carpal tunnel syndrome: a 5-year survivorship analysis.

BACKGROUND: The purpose of our study was to determine the rate of carpal tunnel decompression (CTD) following local corticosteroid injection for carpal tunnel syndrome (CTS), as well as identifying predictors of requiring further intervention and eventual decompression.

METHODS: All patients diagnosed with CTS in our unit over a 6-year period were prospectively assessed. Patients were diagnosed using a combination of clinical presentation and nerve conduction studies. Patients were managed with open carpal tunnel decompression or corticosteroid injection. There were 1,564 consecutive patients diagnosed with CTS over the study period, of whom 824 (53%) underwent a corticosteroid injection as their primary treatment. We performed a survivorship analysis of these patients and used Kaplan-Meier survivorship methodology to determine the 5-year rate of re-intervention. Risk factors for re-intervention were also determined.

RESULTS: The overall 5-year Kaplan-Meier rate of secondary CTD was 15% at 1 year and 33% at 5 years. The need for secondary CTD was independently associated with female gender, diabetes mellitus and positive nerve conduction studies at diagnosis.

CONCLUSIONS: Steroid injection is an appropriate treatment in carefully selected patients. Those who are female, diabetic and have neurophysiological confirmation of diagnosis have the highest risk of relapse. These results may be used to guide initial treatment and counsel patients about the risk relapse.