Mechanical Metatarsalgia as a Risk Factor for Relapse of Morton's Neuroma After Ultrasound-Guided Alcohol Injection

Abstract

Although many treatment modalities are available for Morton's neuroma, the injection of the neuroma with alcohol has gained popularity. However, recently, some investigators have observed a progressive deterioration in pain scores for patients initially pain free after the treatment. The purpose of the present retrospective comparative study was to determine whether mechanical metatarsalgia is related to symptom recurrence. We included 104 consecutive cases of ultrasound-guided alcohol injection for Morton's neuroma in 92 patients. Of these 104 cases, 51 were in group A (49%; Morton's neuroma) and 53 in group B (51%; Morton's neuroma associated with mechanical metatarsalgia). We evaluated each patient using a visual analog scale and American Orthopaedic Foot and Ankle Society forefoot scale, and Johnson satisfaction scale, with a mean follow-up period of 24 (range 12 to 39) months. Concomitant functional and mechanical disorders have been identified and treated with orthopedic inserts. The present study compared the clinical results and recurrence of symptoms in patients with isolated Morton's disease or Morton's disease associated with mechanical metatarsalgia. Of the 104 cases, the patients for 93 cases (89%) were completely satisfied or satisfied with minor reservations. No major complications developed. Symptoms recurred in 6 patients (6%), in whom neuroma was associated with mechanical disorders (p = .0269). Ultrasound-guided alcohol injection of Morton's neuroma is a relatively safe and well-tolerated treatment. Symptom recurrence is often associated with mechanical metatarsalgia. The treatment of the concomitant anatomical and functional disorders that target the genesis of the neuroma has an important role in the prevention of recurrence of this pathology.

Keywords: Morton's disease; forefoot disorders; interdigital neuroma; peripheral nerve disorders; sclerosant injections; ultrasonography.