Outcomes after partial neurectomy of Morton's neuroma related to preoperative case histories, clinical findings, and findings on magnetic resonance imaging scans.

Our purpose was to evaluate the reliability of preoperative case histories, clinical findings, and magnetic resonance imaging (MRI) scans in substantiating the diagnosis of Morton's neuroma and in predicting clinical outcomes after surgical intermetatarsal neurectomy. We studied 19 consecutive patients with histologically proved Morton's neuroma. All had preoperative MRI of the forefoot. Partial neurectomy was performed when there was forefoot pain with transmetatarsal compression and positive findings on MRI scans. Case histories, clinical findings, and findings on MRI scans were correlated with clinical outcomes. Preoperative clinical findings including localization correlated with intraoperative findings in 11 of 19 patients (58%), and MRI scans correlated in 16 of 19 patients (84%). Of the 19 patients, 74% achieved satisfactory outcomes. Neither reliable clinical findings or findings on MRI scans nor confirmation of clinical findings by MRI correlated with a superior result, but 77% of patients with neuromas measuring more than 5 mm in transverse measurement on MRI scans had good outcomes; only 17% with neuromas measuring 5 mm or less had good outcomes. Preoperative localization and diagnosis of Morton's neuroma is better achieved with MRI than through clinical findings. A more favorable clinical outcome can be expected after surgical intermetatarsal neurectomy when a Morton's neuroma has a transverse measurement larger than 5 mm on MRI scans.