Feasibility of an Analgesic Device Enabling Local Anesthetic Delivery and Neuromodulation After Knee Surgery

NCT07336355 | Withdrawn FDA Device

• 1 other identifier: RELAY Knee Feasibility
• Study Type: interventional
• Target: N/A
• Locations: 1 country
• Sites: 1

Brief Summary

Postoperative pain remains undertreated with inadequate analgesic options. Opioids have well-known limitations for both individuals and society; single-injection and continuous peripheral nerve blocks provide intense analgesia but are limited in duration to 24-72 hours; and current neuromodulation options-with a duration measured in weeks and not hours-are prohibitively expensive and require an additional procedure. One possible solution is a device currently under investigation to treat postoperative pain. The RELAY system (Gate Science, Moultonborough, New Hampshire) is comprised of a basic catheter-over-needle device to allow administration of a single-injection of local anesthetic via the needle (or catheter) followed by a perineural local anesthetic infusion via the remaining catheter (when desired). Subsequent to the local anesthetic administration, instead of removing the catheter as with all previous continuous peripheral nerve block equipment, electric current may be delivered via the same catheter and an integrated pulse generator for up to 28 days. This is potentially revolutionary because it would allow an anesthesiologist to deliver (1) a single-injection peripheral nerve block; (2) a continuous peripheral nerve block; and (3) neuromodulation using a single device that can theoretically be placed in the same amount of time required for a single-injection peripheral nerve block. Instead of providing fewer than 24 hours of postoperative analgesia, up to 28 days of pain control could be delivered without disruption of existing practice patterns. The ultimate objective of the proposed investigation is to prepare for a randomized clinical trial investigating the use of the RELAY device to provide postoperative analgesia. This feasibility study will be a series of participants all receiving both local anesthetic and electric current via a single device (RELAY, Gate Science, Moultonborough, New Hampshire). The purpose will be to optimize the insertion approach and stimulation administration during the first 7 days following foot and shoulder surgery as well as training the clinical investigators.

Conditions

Knee Arthropathy

Outcome Measures

Primary Outcomes (1)

• Average Daily Pain Intensity 1st Week [Time Frame: Days 1-4 and 7]

  The median of 5 daily "average" pain intensity scores for Days 1-4 and 7 as measured with the Numeric Rating Scale (0 minimum=best; 10 maximum=worst)

  Days 1-4 and 7

Secondary Outcomes (11)

• Cumulative opioid use 1st week

  The first 7 days following surgery

• Brief Pain Inventory (Interference Sub Scale) Day 3

  Postoperative day 3

• Brief Pain Inventory (Interference Sub Scale) Day 7

  Postoperative day 7

• Worst Daily Pain Intensity 1st Week

  Days 1-4 and 7

• Awakenings Due to Pain 1st Week

  Collected on postoperative days 1, 2, 3, 4, and 7

Study Arms (1)

Experimental Treatment

EXPERIMENTAL

RELAY catheter will be inserted under ultrasound guidance followed by a local anesthetic bolus injection. Within the recovery room, the stimulators will be connected to participants' phones and turned on. The catheters will be removed on postoperative day 7.

Device: Percutaneous peripheral nerve stimulation

Interventions

Percutaneous peripheral nerve stimulation DEVICE

Percutaneous peripheral nerve stimulation with a frequency between 1-250 Hz, a pulse duration of 1-200 µs, and a current of 0.001-10 mA (1-10,000 µA). If the same pattern holds for the RELAY device as for previously tested peripheral nerve stimulators, we will maximize frequency, minimize pulse duration, and have participants adjust the amplitude, as needed.

Also known as: femoral neuromodulation

Experimental Treatment

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adult participants of at least 18 years of age
• Undergoing a rotator cuff repair, total shoulder arthroplasty, ankle arthroplasty/arthrodesis, or foot surgery anticipated to result in moderate-to-severe pain for at least one week
• Planned single-injection peripheral nerve block(s)
• An Android or Apple smart phone able to download the Gate Keeper controller app

You may not qualify if:

• Chronic opioid or tramadol use (daily within prior 2 weeks and duration \> 4 weeks)
• Neuro-muscular deficit of the surgical limb
• Compromised immune system based on medical history (e.g., immunosuppressive therapies such as chemotherapy, radiation, sepsis, infection), or other conditions that places the subject at increased risk of infection
• Implanted spinal cord stimulator, cardiac pacemaker/defibrillator, deep brain stimulator, or other implantable neurostimulator whose stimulus current pathway may overlap
• History of bleeding disorder
• Antiplatelet or anticoagulation therapies other than aspirin
• Allergy to skin-contact materials (occlusive dressings, bandages, tape etc.)
• Incarceration
• Pregnancy
• Moderate pain (NRS \> 3) in an anatomic location other than the surgical site
• Anxiety disorder
• History of substance misuse
• Inability to communicate with the investigators
• Inability to contact the investigators during the treatment period, and vice versa (e.g., lack of telephone access)
• Allergy to amide local anesthetics

Sponsors & Collaborators

• University of California, San Diego: lead
• Gate Science: collaborator

Study Sites (1)

University of California San Diego

La Jolla, California, 92093, United States

Location

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor of Anesthesiology, In Residence

Model Details: A series of participants all receiving active treatment

Study Record Dates

• First Submitted: January 10, 2026
• First Posted: January 13, 2026
• Study Start: March 14, 2026
• Primary Completion: March 14, 2026
• Study Completion: March 14, 2026
• Last Updated: March 17, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF
• Time Frame: Immediately without a set duration limit

Locations

US (1)