A Study of Contralateral Limb Block

Phase 4

Recruiting

• Conditions: Limb Pain, Phantom
• Interventions: Drug: Placebo; Drug: Lidocaine

• Registration Number: NCT06045936
• Lead Sponsor: Mayo Clinic

Brief Summary

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.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2023-09-05
• Study First Submitted QC: 2023-09-13
• Study First Posted: 2023-09-21
• Study Start: 2024-06-18
• Status Verified: 2025-03
• Last Update Submitted: 2025-03-10
• Last Update Posted: 2025-03-12
• Primary Completion: 2025-12
• Study Completion: 2025-12

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 20

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Sham Group	Placebo	Subjects will receive a placebo injection in the back of their residual limb.
Lidocaine Group	Lidocaine	Subjects will receive a lidocaine injection in the back of their residual limb.

Primary Outcome Measures

Name	Time	Method
Change in Functional Improvement	Baseline, 5 days post-injection	Measured using self-reported 20-item Orthotic and Prosthetics User's Survey (OPUS) Lower Extremity Functional Status Measurement survey. Total scores range from 0-100 scale with higher scores indicating a better outcome.
Change in pain	Baseline, 60 minutes post injection	Measured using self-reported Numerical Rating Scale (NRS) where 0=no pain and 10=worst pain.

Secondary Outcome Measures

Name	Time	Method
Step Count	5 days post-injection	Number of daily steps recorded by Modus StepWatch™ or Evolution EvoWalk™ fitted to the participant's prostheses
Change in disability	Baseline, 5 days post-injection	Measured using self-reported 18-item The Groningen Activity Restriction Scale (GARS) that is a general disease independent instrument for measuring disability. Total scores range from 18-72. The higher the score the greater the disability.
Change in Pressure-Pain Algometry	Baseline, 5 days post-injection	Qualified study personnel will measure pain pressure threshold three times at each visit with an algometer on the participant's residual limb at the point of a maximal pain as indicated by the participant during pre-block physical examination, reported in kilopascal (kPa).

Trial Locations

Locations (1)

Mayo Clinic Health System - Mankato; 🇺🇸 Mankato, Minnesota, United States