Ultrasound-Guided Diagnosis and Treatment of Morton's Neuroma

Morton's neuroma is the fibrous enlargement of the interdigital nerve branches, usually in the second and third interspace between the metatarsal heads where the lateral and medial plantar nerves often join. Specific symptoms are dull or sharp pain, numbness and/or tingling in the third and fourth digits, burning sensation, cramping, and a feeling of "walking on a stone" around the metatarsal heads. Numerous clinical tests for Morton's neuroma have been described, such as thumb index finger squeeze, and Mulder's click and foot squeeze tests. Ultrasound and magnetic resonance imaging can be used for confirmation, especially for differential diagnosis, exact localization, and number of neuromas. Further, performing dynamic imaging during the aforementioned tests is paramount and can readily be carried out with ultrasound. The treatment mainly comprises footwear modifications, radiofrequency ablation, physical therapy, local (corticosteroid and anesthetic) injections into the affected webspace, and surgery. Again the use of real-time ultrasound guidance during such interventions is noteworthy.