Ultrasonography-Guided Cryoablation of Morton's Neuroma: Case Series Including Post-ablation Magnetic Resonance Imaging Appearances

Purpose or Learning Objective: Morton's neuroma (MN) is a common compressive neuropathy of the interdigital nerve. Nonsurgical management is recommended initially with many therapies described.

Cryoablation has shown promising results in patients who have failed prior conservative measures such as steroid injection and alcohol ablation; however, published studies are limited.

This study assessed the safety and efficacy of cryoablation in patients with MN, including patient satisfaction. A secondary aim was to evaluate postprocedure magnetic resonance imaging (MRI) appearances at various follow-up intervals.

Methods or Background: A retrospective analysis was completed for 24 patients with MN treated between June 2021 and September 2022. All patients had refractory MN symptoms after previous ultrasonography (US)-guided steroid and lidocaine injection within the previous year. Three patients also had refractory symptoms after prior alcohol ablation.

Cryoablation was performed as a single outpatient procedure under continuous US monitoring and local anesthesia.

Telephone follow-ups were conducted using a 0 to 10 visual analog scale (VAS) score at 6 weeks and 3 months postablation as a minimum. Fourteen patients were followed up at 12 and at 18 months postprocedure. All patients were also encouraged to submit patient-reported outcomes to the British Foot and Ankle Society online scoring database, facilitated by the surgical team.

Postablation MRI was performed to evaluate for postprocedure appearances at various intervals between 3 and 14 months.

Results or Findings: A total of 24 patients with MN were treated; mean size of the MN treated was 12.3 mm. Technical success was 100%, and all patients tolerated the procedure well.

Mean preprocedure VAS pain score was 8, reduced to VAS 1 at 6 weeks and VAS 2 at 3 months at the treated MN site.

High patient satisfaction was expressed with 20 patients (83%) very satisfied. At 12- to 18-month follow-up, 11 of 14 patients (79%) reported complete and sustained pain relief with VAS 0, returning to normal activity without regular analgesia. Four patients had various persistent symptoms and requested repeat cryoablation (17%).

Postablation MRI showed various bone and soft tissue changes in the ablation zone. Two cases of fibrosis in the intermetatarsal space and one residual neuroma were observed, although it was asymptomatic in the ablation site. No complications occurred (e.g., infection, fracture or thermal injury).

Conclusion: US-guided cryoablation is a safe and effective treatment for MN. Clinical advantages include high patient tolerance and satisfaction, a single percutaneous outpatient procedure, sustained pain relief, and reduced risk of scarring/residual neuroma with a short to no disability period compared with postsurgical recovery. Further controlled prospective studies would be beneficial.

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Artikel online veröffentlicht:
26. Mai 2023