THE ROLE OF DIAGNOSTIC BLOCK IN THE MANAGEMENT OF MORTONS NEUROMA

OBJECTIVE: To determine the outcome of surgical excision of Morton's n euroma after a local anesthetic diagnostic block into the neuroma has relieved symptoms. DESIGN: A cohort study. SETTING: A university affil iated hospital. PATIENTS: A Sequential series of 37 patients who under went 41 excisions with at least 2 years' follow-up. Seven patients had undergone repeat excision of a neuroma, and 34 primary excisions were performed. Surgery was performed by a specialist in orthopedic surger y of the foot and ankle. INTERVENTION: Excision of the Morton's neurom a after a positive diagnostic block. MAIN OUTCOME MEASURES: Grade of s ymptoms at follow-up done by independent review on a 4-point scale. RE SULTS: Of 41 procedures, 11 had an unfavourable outcome: 4 procedures were graded 3, and 7 procedures were graded 4. Eight (24%) of the 34 p rimary procedures were reported as failures, and 3 (43%) of the 7 revi sion procedures were reported as failures. Most patients reported poor results owing to persistent pain. CONCLUSIONS: Diagnostic blocks do n ot improve the results of surgery for excision of Morton's neuroma and are not recommended. Because failure rates are greater than 20%, surg ery for Morton's neuroma should only be offered after a full course of nonoperative management.