SLR - November 2019 - Joseph F. Albers
Reference: Shah R, Ahmad M, Hanu-Cernat D, Choudhary S. “Ultrasound-Guided Radiofrequency Ablation for Treatment of Mortons Neuroma: Initial Experience.” Clinical Radiology, 2019, doi:10.1016/j.crad.2019.07.002.Scientific Literature Review
Reviewed By: Joseph F. Albers, DPM
Residency Program: Ascension Wisconsin – Milwaukee, WI
Podiatric Relevance: A Morton’s neuroma refers to a mass-like enlargement of the third common digital nerve of the foot and is one of the most common pain syndromes affecting the forefoot. This is not classified as a true neoplastic neuroma. It is formed by endoneurial edema, abnormal abundant collagen formation, and perineural fibrosis. Etiology is typically secondary to entrapment or repetitive trauma of the nerve. Treatment options include wider shoe gear, metatarsal padding, injections, ablation, surgical decompression, and surgical excision. This study aims to assess the efficacy and safety of ultrasound-guided radiofrequency ablation for the treatment of symptomatic Morton’s neuromas.
Methods: Eighteen patients with symptomatic neuromas confirmed by ultrasound that had a trial of conservative management, including orthotic support and steroid injections in the past. Ultrasound-guided radiofrequency ablation was performed as an outpatient procedure under local anesthetic. Follow up at eight weeks and eight months. Outcomes were assessed with a VAS score, Manchester–Oxford Foot, and Ankle Questionnaire, overall patient satisfaction, and complications. Under continuous real-time ultrasound imaging, up to 10 one-minute cycles of continuous RF were applied at 80 degrees Celsius. Each patient only received a single treatment. No corticosteroid or sclerosing agents were used in adjunct to radiofrequency ablation treatment.
Results: Twenty-two neuromas in 18 patients were treated with radiofrequency ablation under ultrasound guidance. The pre-procedure median VAS score was 8 (7–9), the VAS score decreased by 5 (3–7) from pre-procedure to eight weeks and further by 1 (0–2) from eight weeks to eight months. At eight months, 89 percent of treated patients were satisfied with the procedure outcome. No significant adverse effects were recorded.
Conclusions: Morton’s neuroma is a very common cause for forefoot pain in patients presenting to podiatric clinics. Despite a large prevalence of this pathology, treatment options are still subjected to debate. Much of this is due to a lack of high quality evidence on treatment options. Radiofrequency ablation has been used in the past for treatment of Morton’s neuromas, however this procedure with the use of imaging guidance has shown dramatically improved results compared to older studies that did not use imaging guidance. In the present study 3-10 minute continuous radiofrequency cycles were applied to the neuroma until an ablation zone was seen on real time imaging. Identification of an ablation zone has not been previously described. The response rates for ultrasound-guided radiofrequency ablation are greater than other non-operative interventions of Morton’s neuroma treatments and compares favorably to surgical treatments. Ultrasound-guided radiofrequency ablation is safe and provided excellent results for the patients of this study. This is a treatment that one may consider prior to surgery for patients who have failed other courses of conservative treatment for their Morton’s neuroma.