Treatment of Post-Operative Pain Following Orthopedic Surgery With SPRINT® Peripheral Nerve Stimulation (PNS) System

Treatment of Post-Operative Pain Following Orthopedic Surgery With SPRINT® Peripheral Nerve Stimulation (PNS) System in a Randomized, Double-Blinded, Placebo-Controlled Trial

The purpose of this study is to gather information about how knee pain changes when small amounts of electricity are delivered to the nerves in the leg. This study will involve the use of a Peripheral Nerve Stimulation (PNS) System that is made by SPR Therapeutics (the sponsor of the study). The SPRINT PNS System was cleared by the FDA for up to 60 days of use in the back and/or extremities for the management of acute and chronic pain.

Study Overview

• Status: Completed
• Conditions: Postoperative Pain; Total Knee Arthroplasty; Total Knee Replacement; Partial Knee Replacement
• Intervention / Treatment: Device: SPRINT Peripheral Nerve Stimulation (PNS) System

• Study Type: Interventional
• Enrollment (Actual): 56
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Arkansas
    • Little Rock, Arkansas, United States, 72205
      • University of Arkansas for Medical Sciences
  • California
    • San Diego, California, United States, 92103
      • University of California San Diego
  • Florida
    • Gainesville, Florida, United States, 32607
      • The Orthopaedic Institute
  • Georgia
    • Newnan, Georgia, United States, 30265
      • Better Health Clinical Research, Inc
  • Illinois
    • Evanston, Illinois, United States, 60201
      • Northshore University Healthsystem
  • Louisiana
    • New Orleans, Louisiana, United States, 70115
      • Ochsner Clinic Foundation
  • New Jersey
    • Holmdel, New Jersey, United States, 07733
      • Ali K. Valimahomed MD PLLC
  • North Carolina
    • Chapel Hill, North Carolina, United States, 27599
      • University of North Carolina at Chapel Hill
    • Durham, North Carolina, United States, 27710
      • Duke University
  • Texas
    • San Antonio, Texas, United States, 78229
      • UT Health San Antonio

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Key Inclusion Criteria:

• At least 21 years old
• Underwent a 1. primary total knee replacement (TKR), 2. secondary/revision TKR or 3. Partial/unicompartmental knee replacement (PKR)
• Knee pain directly resulting from Knee Replacement surgery in affected knee

Key Exclusion Criteria:

• Current high opioid use
• Body Mass Index (BMI) > 40 kg/m2
• Conditions with increased risk of infection
• Implanted electronic device
• History of bleeding or clotting disorder.
• Uncontrolled Diabetes Mellitus Types I or II
• Pregnancy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Group 1 (Treatment); Participants in Group 1 will have Leads placed by the nerves of the mid to upper thigh. These participants will then use the SPRINT Peripheral Nerve Stimulation (PNS) System and will receive electrical stimulation for 8 weeks.	Device: SPRINT Peripheral Nerve Stimulation (PNS) System; The SPRINT System delivers mild electrical stimulation to nerves in the affected limb. The SPRINT System includes two small wires (called "Leads") that are placed through the skin in the upper leg. It also includes a device worn on the body that delivers stimulation (called the SPRINT Stimulator).; Other Names: SPRINT; SPRINT System
Sham Comparator: Group 2 (Control); Participants in Group 2 will have Leads placed by the nerves of the mid to upper thigh. These participants will then use the SPRINT Peripheral Nerve Stimulation (PNS) System and receive 8 weeks of sham stimulation. Participants will then have the option to crossover and receive stimulation therapy.	Device: SPRINT Peripheral Nerve Stimulation (PNS) System; The SPRINT System delivers mild electrical stimulation to nerves in the affected limb. The SPRINT System includes two small wires (called "Leads") that are placed through the skin in the upper leg. It also includes a device worn on the body that delivers stimulation (called the SPRINT Stimulator).; Other Names: SPRINT; SPRINT System

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Reduction in Average Pain Intensity: Number of Participants With ≥ 50% Reduction in Average Pain Intensity	All participants were asked to complete daily diaries to record their average knee pain during the past 24 hours on each day of a 7-day period using an 11-point numerical rating scale where 0 represents "No Pain" and 10 represents "Pain as bad as you can imagine." The average pain scores were calculated across the 7-day diary(s) at baseline and across weeks 5 to 8 post-start of treatment. Percent reduction was then calculated for each participant. To be considered a success, participants must have experienced ≥ 50% reduction in average knee pain. The number of successes is presented.	Baseline and 5 to 8 weeks post-Start of Treatment (SOT)
Study-Related Adverse Device Effects	At each study visit following the baseline assessment at Visit 1, participants were questioned if any changes in their medical status or condition have occurred since their previous visit. If the participant experienced a change that was a study-related adverse event, an Adverse Event Form was completed by the site. The number of participants that experienced at least one study-related adverse event is reported here. Adverse Events are reported by the trial phase in which they occurred: Group 1 Treatment (active stimulation), Group 2 Control (sham stimulation), and Group 2 Crossover Safety Set (active stimulation).	Up to 13 months for each Group 1 participant and up to 16 months for Group 2 participants that opted to cross over (time from baseline to last study visit)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Reduction in Average Pain Intensity: Number of Participants With ≥ 50% Reduction in Average Pain Intensity	All participants were asked to complete daily diaries to record their average knee pain intensity during the past 24 hours on each day of a 7-day period using an 11-point numerical rating scale where 0 represents "No Pain" and 10 represents "Pain as bad as you can imagine." The average pain score was calculated across the 7-day diary(s) at baseline and across weeks 1 to 4 post-start of treatment. Percent reduction was then calculated for each participant. To be considered a success, participants must have experienced ≥ 50% reduction in average knee pain. The number of successes is presented.	Baseline and 1 to 4-weeks post-start of treatment (SOT)
Long-term Durability of Average Pain Relief: Number of Participants With ≥ 50% Reduction in Average Pain Intensity	All participants were asked to complete daily diaries to record their average knee pain intensity during the past 24 hours on each day of a 7-day period using an 11-point numerical rating scale where 0 represents "No Pain" and 10 represents "Pain as bad as you can imagine." The average pain score was calculated across the 7-day diary for each participant at baseline and at 3-, 6-, 9-, and 12-months post-start of treatment. Percent reduction was then calculated for each participant. To be considered a success, participants must have experienced ≥ 50% reduction in average knee pain. The number of successes is presented.	Baseline, 3-months post-start of treatment (SOT), 6-months post-SOT, 9-months post-SOT, 12-months post-SOT
Mean Pain Relief	All participants were asked to complete daily diaries to record their average knee pain intensity during the past 24 hours on each day of a 7-day period using an 11-point numerical rating scale where 0 represents "No Pain" and 10 represents "Pain as bad as you can imagine." The mean pain score was calculated across the 7-day diary(s) for each participant at baseline, 1-4 weeks post-start of treatment (SOT), 5-8 weeks post-SOT, and at 3-, 6-, 9-, and 12-months post-SOT. The mean pain score is presented.	Baseline, 1 to 4-weeks post-start of treatment (SOT), 5 to 8-weeks post-SOT, 3-months post-SOT, 6-months post-SOT, 9-months post-SOT, and 12-months post-SOT
Pain Medication Usage	Participants recorded the amount/type of analgesics used in daily diaries. A blinded, third-party medication committee reviewed participants' diary medications for each time period to determine if each participant's analgesic usage changed. The committee determined whether there was No change (no change in dosage or change is not clinically meaningful to impact pain outcomes), an Increase (clinically meaningful increase in medication that would impact pain outcomes), or a Decrease (clinically meaningful decrease in medication that would impact pain outcomes) for each time period compared to baseline. The number of participants with a Decrease in analgesic medication usage for pain are reported. Participants that did not report any pain medications during the study were excluded from the analysis.	Baseline, 1 to 4 weeks post-start of treatment (SOT), and 5 to 8 weeks post-SOT, 3-months post-SOT, 6-months post-SOT, 9-months post-SOT, and 12-months post-SOT
Pain Catastrophizing Scale (PCS)	The Pain Catastrophizing Scale (PCS) questionnaire has 13 questions that assess rumination, magnification, and helplessness. Participants are asked to think back on painful experiences in the past and reflect on how often they had specific thoughts or feelings. Each of the 13 questions is scored on a 5-point scale where 0 represents "not at all," and 4 represents "all the time." The scores from each question were summed for each participant to provide a total PCS score, with a possible range from 0 to 52 with higher scores indicating a greater tendency to catastrophize pain (i.e. a higher score indicates a worse outcome). The mean score for each time point is presented.	Baseline (Visit 1), 4-weeks post-SOT (Visit 6), and 8-weeks post-SOT (Visit 10)
Patient Global Impression of Change (PGIC)	The Patient Global Impression of Change (PGIC) Survey asks participants to rate their improvement with treatment on a 7-point scale ranging from -3 to 0 to +3, where -3 represents "very much worse," 0 is "no change," and +3 represents "very much improved" as compared to before stimulation treatment. The participants combine all the components of their experience into one overall score. The mean score of each group was calculated for each time frame.	4-weeks post-start of treatment (SOT)(Visit 6), 8-weeks post-SOT (Visit 10), 3-months post-SOT (Visit 11), 6-months post-SOT (Visit 12), 9-months post-SOT (Visit 13), and 12-months post-SOT (Visit 14)
Pain Interference: Number of Participants With ≥ 50% Reduction in Pain Interference	Question 9 of the Brief Pain Inventory-Short Form (BPI-9) is a 7-part question that assesses the level of interference that participants experience in their daily lives due to pain. The 7 categories are general activity, mood, walking ability, normal work, relations with other people, sleep, and enjoyment of life. Participants were asked to rate how much their post-surgical knee pain interferes with each aspect on an 11-point numerical scale where 0 represents "Does Not Interfere" and 10 represents "Completely Interferes." The average of these 7 scores was calculated for each participant at each time point. Percent reduction was then calculated for each participant. To be considered a success, participants must have experienced ≥ 50% reduction in pain interference. The number of successes is presented.	Baseline (Visit 1), 8-weeks post-start of treatment (SOT) (Visit 10), 3-months post-SOT (Visit 11), 6-months post-SOT (Visit 12), 9-months post-SOT (Visit 13), and 12-months post-SOT (Visit 14)
Function (i.e., Physical Recovery)	The Western Ontario and McMaster University Osteoarthritis Index (WOMAC) questionnaire consists of 24 items that evaluate pain, stiffness, and physical functional disability. Each item is scored on an 11-point numerical rating scale from 0 to 10, where higher scores indicate greater pain, stiffness, and disability. For each participant, the scores from each of the 24 items were averaged to calculate the participant's total score, with a minimum score of 0 and a maximum score of 10. The mean total score was then calculated across participants and percent reduction was calculated for each time point. To be considered a success, participants must have experienced ≥ 33% reduction in their score. The number of successes is presented.	Baseline (Visit 1), 8-weeks post-start of treatment (SOT) (Visit 10), 3-months post-SOT (Visit 11), 6-months post-SOT (Visit 12), 9-months post-SOT (Visit 13), and 12-months post-SOT (Visit 14)
Six Minute Walk Test (6MWT)	The total distance that a participant could walk in 6 minutes was recorded, and participants unable to walk at all were given a score of 0 meters. The mean distance was then determined across participants. The baseline score was compared to the score at the specified intervals after start of therapy.	Baseline (Visit 1), 8-weeks post-start of treatment (SOT) (Visit 10), and 3-months post-SOT (Visit 11)

Collaborators and Investigators

• Sponsor: SPR Therapeutics, Inc.
• Collaborators: United States Department of Defense

Study record dates

Study Major Dates

• Study Start (Actual): August 6, 2020
• Primary Completion (Actual): June 27, 2024
• Study Completion (Actual): June 27, 2024

Study Registration Dates

• First Submitted: April 7, 2020
• First Submitted That Met QC Criteria: April 7, 2020
• First Posted (Actual): April 10, 2020

Study Record Updates

• Last Update Posted (Estimated): August 27, 2025
• Last Update Submitted That Met QC Criteria: August 26, 2025
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Keywords: Pain; Nervous System Diseases; Musculoskeletal Diseases; Neurologic Manifestations; Postoperative Complications; Signs and Symptoms; Pain, Postoperative
• Additional Relevant MeSH Terms: Pathologic Processes; Pathological Conditions, Signs and Symptoms; Pain; Pain, Postoperative; Neurologic Manifestations; Musculoskeletal Diseases; Nervous System Diseases; Postoperative Complications; Signs and Symptoms; Therapeutics; Drug Therapy; Drug Delivery Systems
• Other Study ID Numbers: 0150-CSP-000; CDMRP-OR170165 (Other Grant/Funding Number: Department of Defense)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No