Electrical Stimulation for the Treatment of Pain Following Total Knee Arthroplasty (TKA) Using the SPRINT System

A Prospective Case Series Study of SPR Peripheral Nerve Stimulation (PNS) Therapy for the Treatment of Pain Following Total Knee Arthroplasty (TKA) Utilizing Preoperative Lead Placement

The purpose of this study is to determine if electrical stimulation (small levels of electricity) can safely and effectively reduce pain following total knee replacement (or total knee arthroplasty (TKA)). This study involves a device called the SPRINT System. The SPRINT System delivers mild electrical stimulation to nerves in the leg that received the knee replacement. The SPRINT System includes a small wire (called a "lead") that is placed through the skin in the upper leg. It also includes a device worn on the body that delivers stimulation (called the SPRINT Stimulator).

Study Overview

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

• Study Type: Interventional
• Enrollment (Actual): 24
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • La Jolla, California, United States, 92037
      • University of California San Diego
  • North Carolina
    • Durham, North Carolina, United States, 22710
      • Duke University Medical Center
  • Ohio
    • New Albany, Ohio, United States, 43054
      • Joint Implant Surgeons

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Key Inclusion Criteria:

• At least 21 years old
• Scheduled to undergo a primary unilateral total knee replacement procedure

Key Exclusion Criteria:

• Body Mass Index (BMI) > 40 kg/m2
• Compromised immune system based on medical history
• History of valvular heart disease
• Implanted electronic device
• Joint or overlying skin infection of the affected limb
• History of recurrent skin infections
• Bleeding disorder
• Allergy to skin surface electrodes and/or medical-grade adhesive tapes
• Pregnant

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: NA
• Interventional Model: SINGLE_GROUP
• Masking: NONE

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

EXPERIMENTAL: Peripheral Nerve Stimulation; All study subjects will have up to 2 Smartpatch Leads placed in their leg that underwent total knee replacement, will use the SPRINT Peripheral Nerve Stimulation (PNS) System, and will receive electrical stimulation.

Device: SPRINT Peripheral Nerve Stimulation (PNS) System; The SPRINT System is an Investigational Device which delivers mild electrical stimulation to nerves in the leg that underwent lead placement. The SPRINT System includes a small wire (called a "Lead") that is 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: Smartpatch System; SPRINT System; Smartpatch

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Average Knee Pain While Walking	Subjects were asked to complete daily diaries to track their average pain intensity while walking during the past 24 hours over a 7-day period on an 11-point numerical rating scale where 0 represents "No Pain" and 10 represents "Pain as bad as you can imagine." The average score for each diary period was calculated across subjects, and the mean scores for weeks 1-4 is reported.	Postoperative Day 0 to 28 (first 4 weeks following Total Knee Arthroplasty (TKA))
Number of Participants That Experienced at Least One Study-Related Adverse Event	At each study visit following the baseline assessment at Visit 1, subjects were questioned if any changes in their medical status or condition has occurred since their previous visit. If the subject experienced a change that was an adverse event, an Adverse Event Form was completed by the site. The number of subjects that experienced at least one study-related adverse event is reported here.	Total of 21 months (from when the first subjects enrolled to when the last subject completed the study)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Average Knee Pain Over the Last 24 Hours	Subjects were asked to complete daily diaries to track their average pain intensity in the past 24 hours over a 7-day period on an 11-point numerical rating scale where 0 represents "No Pain" and 10 represents "Pain as bad as you can imagine." The average score for each diary period was calculated across subjects, and the mean score for weeks 1-4 is reported.	Postoperative Day 0 to 28 (first 4 weeks following Total Knee Arthroplasty (TKA))
Average Knee Pain at Rest	Subjects were asked to complete daily diaries to track their average pain intensity at rest in the past 24 hours over a 7-day period on an 11-point numerical rating scale where 0 represents "No Pain" and 10 represents "Pain as bad as you can imagine." The average score for each diary period was calculated across subjects, and the mean score for weeks 1-4 is reported.	Postoperative Day 0 to 28 (first 4 weeks following Total Knee Arthroplasty (TKA))
Amount of Analgesic Usage	The amount and type of analgesics used by subjects was recorded in daily diaries. Narcotic usage was converted into a morphine equivalent dosage (MED), which is measured in units of morphine milligram equivalents (MME). Diaries were collected at various visits throughout the study, and for consistency, these data were translated into post-operative days. The average MED was calculated for each subject for the first 42 days (6 weeks) following surgery, and the median of these averages was determined across subjects.	Visit 4 (Day of Surgery) and Visits 6-11 (weeks 1-6 post-Total Knee Arthroplasty (TKA))
Number of Participants That Experienced at Least One Opioid-Related Side Effect	Throughout the study, subjects were asked if they experienced any side effects related to opioid pain medications. The occurrences of these side effects were recorded and were not reported as Adverse Events. The number of subjects that experienced at least one opioid-related side effect at each visit is reported.	Visit 1 (Baseline), Visit 2 (Lead Placement), Visits 5-13 (in-hospital days through 3-months post-Total Knee Arthroplasty (TKA))
Time to Achieve 90 Degrees Flexion in Affected Knee	Active range of motion (AROM; no assistance from clinical staff) and passive range of motion (PROM; assisted by clinical staff) was assessed with both stimulation on and off. The time that it took subjects to achieve the milestone of 90 degrees of knee flexion in their affected leg is reported.	Visit 2 (Lead Placement), Visit 7 (3-weeks Post-Total Knee Arthroplasty (TKA)), Visit 11 (6-weeks Post-TKA), Visit 13 (3-months Post-TKA)
Timed Up and Go (TUG) Test	Subjects began this test from a seated position in a standard chair and were timed while they stood up, walked to a marked point 10 feet away (at a normal, safe pace), returned to the chair, and sat down. Timed Up and Go (TUG) test times are expected to be greater immediately after surgery as compared to baseline.	Visit 1 (Baseline), Visit 5 (In-Hospital), Visit 7 (2-weeks Post-Total Knee Arthroplasty (TKA)), Visit 11 (6-weeks Post-TKA), Visit 13 (3-months Post-TKA)
6 Minute Walk Test (6MWT)	The total distance that a subject could walk in 6 minutes was recorded, and the mean distance was determined across subjects. 6 Minute Walk Test distances are expected to be reduced immediately after surgery as compared to baseline.	Visit 1 (Baseline), Visit 7 (2-weeks Post-Total Knee Arthroplasty (TKA)), Visit 11 (6-weeks Post-TKA), Visit 13 (3-months Post-TKA)
Fixed Distance Walk Test	The amount of time it took subjects to walk a fixed distance of 20 meters was recorded.	Visit 1 (Baseline) and Visit 5 (In-Hospital)
Percent Change From Baseline on the Western Ontario McMaster University Osteoarthritis Index (WOMAC)	The Western Ontario 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 subject, the scores from each of the 24 items were summed to calculate the subject's total score, with a minimum score of 0 and a maximum score of 240. Percent change from baseline was calculated for each subject at each time point (i.e., value at Visit 5 vs. Baseline rating, value at Visit 7 vs. Baseline rating, value at Visit 11 vs. Baseline rating, and value at Visit 13 vs. Baseline rating). The median percent change across subjects was determined. Negative values indicate worsening since Baseline, while positive values indicate improvement from Baseline. Percent improvement = 100 x ([rating at each study visit]-[rating at baseline]) / [rating at baseline].	Visit 1 (Baseline), Visit 5 (In-Hospital), Visit 7 (2-weeks Post-Total Knee Arthroplasty (TKA)), Visit 11 (6-weeks Post-TKA), Visit 13 (3-months Post-TKA)
Knee Pain Interference With Daily Activities	Subjects were asked to rate the degree to which their knee pain has interfered with 7 different aspects of their daily life on a scale from 0 to 10, with higher scores indicating greater interference. Those 7 scores were averaged for each subject to provide an overall pain interference score, with a possible range of 0 to 10 with higher scores indicating greater interference. The median score was then calculated across subjects.	Visit 1 (Baseline), Visit 2 (Lead Placement), Visits 5-13 (in-hospital days through 3-months post-Total Knee Arthroplasty (TKA))
Number of Participants Reporting Meaningful Improvement, Minimal or No Change, or Meaningful Worsening on the Patient Global Impression of Change (PGIC) Survey	The Patient Global Impression of Change (PGIC) asks subjects to rate their improvement with treatment on a 7-point scale ranging from "very much worse" to "very much improved" as compared to before their knee replacement surgery. The subjects combine all the components of their experience into one overall score. Ratings of Much- or Very Much Improved are considered Meaningful Improvements; similarly, ratings of Much- or Very Much Worse are categorized as Meaningfully Worse.	Visits 5-13 (in-hospital through 3-months post-Total Knee Arthroplasty (TKA))
Pain Catastrophizing Scale (PCS)	The Pain Catastrophizing Scale (PCS) questionnaire has 13 questions that assess rumination, magnification, and helplessness. Subjects 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 subject 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 median scores were then calculated across all subjects.	Visit 1 (Baseline), Visit 11 (6-weeks post-Total Knee Arthroplasty (TKA)), Visit 13 (3-months post-TKA)
Time to Meet Recovery Milestones up to Three Months Post-Total Knee Arthroplasty (TKA)	Participants were queried weekly from the date of their Total Knee Arthroplasty (TKA) until they met specific, post-surgical recovery milestones. Participants were queried up through the time at which they meet each milestone or through their completion of the study, whichever came first (up to three months post-surgery).	From Day of Surgery through completion of milestone or 3-months from Day of Surgery, whichever came first
Subject Satisfaction Survey	Subjects completed a sponsor-developed survey with questions pertaining to their feelings about the SPRINT Stimulation System as a method for managing post-surgical pain.	Visit 11 (6-weeks post-Total Knee Arthroplasty (TKA))

Collaborators and Investigators

• Sponsor: SPR Therapeutics, Inc.

Study record dates

Study Major Dates

• Study Start (ACTUAL): October 22, 2015
• Primary Completion (ACTUAL): July 17, 2017
• Study Completion (ACTUAL): July 17, 2017

Study Registration Dates

• First Submitted: April 22, 2015
• First Submitted That Met QC Criteria: June 10, 2015
• First Posted (ESTIMATE): June 11, 2015

Study Record Updates

• Last Update Posted (ACTUAL): September 4, 2018
• Last Update Submitted That Met QC Criteria: August 30, 2018
• Last Verified: August 1, 2018

More Information

Terms related to this study

• Keywords: electrical stimulation; total knee arthroplasty; neuromodulation; neurostimulation; TKA pain; pain following total knee replacement
• Additional Relevant MeSH Terms: Musculoskeletal Diseases
• Other Study ID Numbers: 0141-CSP-000