Ultrasonographic diagnosis of recurrence after excision of an interdigital neuroma.

We retrospectively reviewed the records of 20 patients (21 feet) with previous interdigital neuroma resections and symptoms suggestive for, but not diagnostic of, recurrent neuroma. Sonography was performed when clinical findings supplemented by local anesthetic block did not conclusively confirm the presence of recurrent neuroma. Studies performed in 13 patients (14 feet) were positive for recurrent neuromas. Three studies were indeterminate. The remaining four studies were negative for recurrent neuroma. The ultrasound studies were performed at an average of 19.2 months (range, 2-82 months) after the resection. Nine patients with 11 previous interdigital neuromas underwent ultrasonographic examination of the forefoot and subsequent revision neuroma resection. At surgery, gross and histologic findings were consistent with recurrent neuroma in 10 of 11 cases; one patient was found to have metatarsal-phalangeal synovitis. Ultrasonography appears to be a useful means for confirming neuroma recurrence in patients with symptoms after interdigital neurectomy when the diagnosis is not clear on physical examination.

Sonographic evaluation of interdigital neuromas.

Fifty surgical patients with symptoms suggestive of Morton's neuroma underwent preoperative ultrasound examination of the forefoot using a 7.5 MHz transducer. Fifty-five neuromas were excised. Of these, one neuroma had a ganglion associated with it and five neuromas were recurrent. Four feet had adjacent neuromas. Ultrasound accurately predicted the presence, location and size of the neuromas in 98% of the cases. There were no false positives. In all cases in which a neuroma was predicted by ultrasound, it was confirmed grossly at the time of surgery and later by histological exams. We conclude that ultrasound is an accurate technique in the diagnosis of interdigital neuromas.