Intralesional therapy in carpal tunnel syndrome: a sonographic-guided approach.

OBJECTIVE: The aim of this pictorial essay is to show a representative example of sonographic-guided injection in carpal tunnel syndrome associated with tenosynovitis of the finger flexor tendons. METHODS: Images were obtained using a real-time ultrasound system (AU4-idea; Esaote Biomedica, Genoa, Italy) equipped with a 13-MHz linear transducer. The best injection site was detected using a fine metal clip placed between the skin and the transducer. The images here were obtained in a patient with rheumatoid arthritis and carpal tunnel syndrome secondary to tenosynovitis of the finger flexor tendons. RESULTS: Steroid injection within the carpal tunnel under sonographic control was easily performed. All steps of the needle placement within the widened tendon sheath were carefully evaluated on the monitor screen. Marked clinical improvement occurred shortly thereafter (3 days) and increased over the next 6 weeks. CONCLUSION: A detailed assessment of the carpal tunnel and a correct, safe placement of the needle for steroid injection can be quickly performed under sonographic guidance.