RESUMEN
BACKGROUND: The purpose of this study was to evaluate the efficacy of corticosteroid injection and determine the duration of symptom-free period after treatment with a single ultrasound-guided injection for a painful Morton's neuroma. MATERIALS AND METHODS: From May 2002 to November 2003, 35 consecutive patients (7 males, 28 females) (mean age, 54; age range, 29 to 77 years) underwent a single ultrasound guided corticosteroid injection. Thirty-nine injections were performed as 4 patients had bilateral Morton's neuromas. The injection of 1.0 cc Celestone Chronodose (5.7 mg/ml) with 0.5 cc of 1% lidocaine was performed into the symptomatic intermetatarsal web-space. The efficacy of the injection was determined by the Johnson grading scale, and modified lower extremity functional scale. RESULTS: On the Johnson scale, 15 of 39 (38%) neuromas showed complete satisfaction 9 months after treatment and 11 of 39 (28%) were satisfied with minor reservations. A total of 26 of 39 (66%) neuromas had a positive outcome 9 months after the injection. On the functional daily activity (FDA) scale, 20 of 39 (51%) neuromas showed no difficulty and 4 of 39 (10%) indicated minor difficulties, which was considered a positive outcome 9 months after injection. Complete pain relief was achieved in 11 of 39 (28%) neuromas 9 months after treatment. Twelve of 39 (31%) neuromas did not respond to conservative treatment and required surgery. The results of treatment suggested improvement in efficacy if injection was used early. The size of the lesion measured on ultrasound showed no correlation with pain relief after injection. CONCLUSION: A single corticosteroid injection can offer short-term pain relief in the conservative management of Morton's neuroma.