New technique of ultrasound-guided injection in the carpal tunnel syndrome

Abstract

In conventional ultrasound-guided corticosteroid injection in carpal tunnel syndrome (CTS), the entry point is usually at the distal crease of the wrist. However, actual pathology of CTS is caused by thickening of the transverse carpal ligament (TCL). Injection of corticosteroid can reduce inflammation and ameliorate the symptoms, but it cannot reduce the thickness of TCL. If we change the entry point to just 10 mm below the distal crease rather than at the distal crease, we can inject corticosteroid around the median nerve and into the TCL. Five patients with CTS treated with ultrasound-guided corticosteroid injection around median nerve and into the TCL. The diagnosis of CTS was made by history, physical examination, sonographic evaluation, and electrophysiologic confirmation. Sonographic examinations were performed by one physiatrist using Samsung scanner with a 5–12 MHz linear transducer. Standard 23-gauge needles were used for administration of local anesthetics and triamcinolone mixture (total 1 cm 3 ). After transverse view and longitudinal view, the entry point was determined. The entry point was below the distal crease, where the needle could easily introduce the injection material into the thickened TCL. The direction of the needle entry point was from lateral to ulnar side. Total of five female patients with CTS were included. The mean age was 55.4 ± 3.6 years. The mean duration of disease was 4.6 (range 3–8 mo) months. The results were good to excellent in all patients. There were no complications during the procedure. Ultrasound-guided corticosteroid injection in CTS, combined with injection at the thickened TCL may be a good method and further research is needed to confirm the usability.