This research is being done to determine if an anesthetic like Lidocaine, may be effective when injected around the sciatic nerve of the intact limb in patients with limb loss pain on the contralateral side.

Inclusion Criteria:

• Lower extremity amputation performed more than 12 months before study enrollment
• PLP/RLP in affected amputated limb > 4 on NRS26
• Pain duration of more than 6 months despite a trial of conservative therapies for at least 2 months, including oral medications, topical medicines, physical therapy, and physical modalities (i.e., heat, cold, transcutaneous electrical nerve stimulation, phonophoresis)
• Willingness to undergo image guided diagnostic nerve block

Exclusion Criteria:

• Refusal / inability to participate or provide consent
• Contraindications to diagnostic nerve block
• Non-neurogenic source of PLP/RLP
• Current opioid use > 50 morphine milligram equivalents per day
• Any interventional pain treatment in the residual limb within the last 30 days
• Severe uncontrolled medical condition (i.e., hypertensive crisis, decompensated hypothyroidism)
• Use of investigational pain drug within past 30 days or other concurrent clinical trial enrollment