Compare Ultrasound Assisted Cold Therapy and Lidocaine Injection to Treat Morton's Neuroma

This study will be a 3-arm randomized single-blinded placebo controlled study in which human
subjects with intermetatarsal neuralgia will receive subcutaneous normal saline or
subcutaneous lidocaine or ultrasound guided cryoablation. The first follow up will take place
4 weeks post procedure to monitor the magnitude and duration of pain relief. Subjects will
then be crossed over. Those who had received saline or lidocaine will receive ultrasound
guided cryoablation. Individuals, who had previously been given ultrasound guided
cryoablation without any improvement, may opt for another denervation procedure at 4 weeks.
All of the participants will be followed up at 3 months post procedure to determine the
magnitude and duration of pain relief.

Study procedures will be conducted by the principle investigator who is a Board Certified
pain management attending physician and an expert in performing ultrasonography guided
interventions The cryoablation device is routinely used to treat various painful pathologies
at Mount Sinai and Beth Israel pain management offices. The device manual and instructions
will be available at both locations. All research staff has prior experience working with
individuals with foot and ankle injuries at Mount Sinai.

Inclusion Criteria:

- Between the ages of 18 and 80 years old

- Magnetic Resonance Imaging (MRI) confirmed diagnosis of Morton's neuroma - Refractory
(greater than 3 month) symptoms to multiple conservative management, including
physical therapy, nonsteroidal anti-inflammatory drugs (NSAIDS) and foot orthotics.

- No history of systemic inflammatory conditions such as rheumatoid arthritis

- Able to give written informed consent - Subject has been on a stable dose of analgesic
mediation (or not on analgesic medication) for at least 3 weeks and is agreeable to
remaining on current regimen for the duration of the study.

Exclusion Criteria:

- Diagnosed complex regional pain syndrome (CRPS)

- Pregnancy - History of intolerance, hypersensitivity or known allergy to lidocaine -
Recent history of recent surgical intermetatarsal neuronectomy (within previous 6
months) - Coagulation disorder - Current infection

- Intermetatarsal bursitis

- Metatarsophalangeal joint instability/capsulitis

- Metatarsal stress fracture

- Lumbar radiculopathy

- Tarsal tunnel syndrome

- Frieberg's infraction

- Painful callosities associated with toe deformities

- Peripheral neuropathy

- Diabetes mellitus and peripheral vascular diseases

- Insufficient command of English to complete self-¬report instruments.