Submission Status: Accepted
INSTITUTION: University of Arizona Medical Center
Medical Imaging

Primary Category: Musculoskeletal
Secondary Category: Ultrasound
Sun Nov 29 2015 12:30PM – 1:00PM ROOM Learning Center, Hall D
Sonographic Evaluation of Morton’s Neuroma Prior to and Following Laser Therapy
D Melville, MD, Tucson, AZ; M P Del Giudice, MD; D A Bocian, DPM; L H Gimber, MD; E A Krupinski, PhD; M S Taljanovic, MD

Purpose

To retrospectively assess for differences in imaging appearances of Morton’s neuromas prior to and following laser therapy using ultrasound (US).

Method and Materials

Following IRB approval, a retrospective review was performed identifying 42 patients who underwent US to evaluate for Morton’s neuroma prior to laser therapy. Sonographic and MRI reports and images were reviewed in correlation with clinical history. The final study group consisted of 21 patients, who underwent US of 24 feet prior to laser therapy followed by post-treatment US. A retrospective consensus review of the US from patients with treated Morton’s neuromas was then carried out to characterize the appearances of these lesions prior to and following therapy. Data was then evaluated to identify US variables associated with laser therapy. When available, comparison of US to MR images was performed to assess lesion visibility.

Results

Of 42 patients undergoing Morton’s neuroma evaluation by US, 21 underwent treatment of a total of 32 Morton’ neuromas. Retrospective US review of the pre-treatment lesion showed heterogeneously, hypoechoic masses with well-defined borders with associated pain on transducer pressure in 97% (31/32). An associated bursa (3/28) was identified in a minority of cases. Following treatment the lesions remained heterogeneously hypoechoic but most demonstrated ill-defined borders (23/31) with significantly decreased or absent pain with transducer pressure (29/31). Statistical analysis revealed significant differences in appearance of pre and post-treatment lesion borders (p<0.0001) and pain with transducer pressure (p<0.0001), as well as the presence of an associated intermetarsal bursa (p<0.05), which resolved following treatment, but not size. Finally, all neuromas were determined to be better visualized on US compared to MRI.

Conclusion

US is an excellent imaging technique for assessment of Morton’s neuromas and may be used to identify post-treatment changes following laser therapy for Morton’s neuroma, which include ill-defined lesional borders, resolution of bursae and improved/absent pain with pressure, and these criteria may be applied in future clinical studies evaluating the efficacy of laser therapy for this condition.

Clinical Relevance/Application

Post-treatment US changes following laser therapy for Morton’s neuromas include ill-defined lesion borders, resolution of intermetatarsal bursal fluid and improved/absent pain with transducer pressure.