ReActiv8 Post Market Surveillance Registry for the ReActiv8 Implantable Neurostimulation System for Chronic Low Back Pain
Conditions: Chronic Low Back Pain
Sponsor: Mainstay Medical

ReActiv8-C Post Market Surveillance Registry
The contents of this document are confidential and are not to be reproduced or made available to third parties without prior 
consent from Mainstay Medical and are not to be used in any unauthorized way.
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Document Number 950066, Rev. G
27-MAY-2020
ReActiv8 
Post Market Surveillance Registry
(ReActiv8-C)
for the 
ReActiv8 Implantable Neurostimulation System
for Chronic Low Back Pain
Sponsor
Mainstay Medical Limited
Clonmel House,
Forster Way,
Swords, Co. Dublin, K67F2K3
Ireland
ClinicalTrials.gov ID: NCT03255200

ReActiv8-C Post-Market Surveillance Registry
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consent from Mainstay Medical and are not to be used in any unauthorised way.
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Document Number 950066, Rev. G
27-MAY-2020
Investigator Signature Page
Investigator Acknowledgement Signature:
I have received and reviewed this Post-Market Surveillance Registry. I will conduct the 
Registry as described.
_________________________________
___________
Investigator’s Name (print)
Site Number
_________________________________
___________
Investigator’s Signature
Date

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Document Number 950066, Rev. G
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Table of Contents
1.
Registry Summary............................................................................................. 6
2.
Background........................................................................................................ 7
2.1.
Chronic Low Back Pain ............................................................................................. 7
2.2.
ReActiv8.................................................................................................................... 8
3.
ReActiv8 Therapy .............................................................................................. 9
3.1.
Summary of ReActiv8................................................................................................ 9
3.1.1.
Implantable Components of ReActiv8 ....................................................................... 9
3.1.2.
Non-Implantable Components of ReActiv8 ............................................................... 9
3.2.
Indications for Use................................................................................................... 10
3.3.
Contraindications..................................................................................................... 10
3.4.
Surgical Implantation and Device Activation ............................................................ 10
3.5.
Physician and Health Care Personnel Training........................................................ 10
4.
Registry Design ............................................................................................... 11
4.1.
Objective ................................................................................................................. 11
4.2.
Overview ................................................................................................................. 11
4.3.
Enrolment Criteria ................................................................................................... 11
4.3.1.
Inclusion Criteria ...................................................................................................... 11
4.3.2.
Exclusion Criteria..................................................................................................... 11
4.4.
Safety Reporting...................................................................................................... 11
4.4.1.
Adverse Events........................................................................................................ 11
4.4.2.
Unavoidable Events................................................................................................. 13
4.4.3.
Reporting by the Investigator................................................................................... 13
4.4.4.
Reporting by the Sponsor ........................................................................................ 13
4.5.
Performance Measures ........................................................................................... 13
4.5.1.
Low Back Pain – NRS ............................................................................................. 13
4.5.2.
Disability – ODI ........................................................................................................ 14
4.5.3.
Quality of Life – EQ-5D............................................................................................ 14
4.5.4.
Percent Pain Relief (PPR) ....................................................................................... 14
4.5.5.
Subject Global Impression of Change (SGIC)......................................................... 14
4.5.6.
Treatment Satisfaction Questionnaire (TSQ) .......................................................... 14
4.6.
Health Care Utilization............................................................................................. 15
4.7.
Data Collection Schedule ........................................................................................ 15
4.7.1.
Visit 1: Baseline Visit ............................................................................................... 15
4.7.2.
Visit 2: Activation Visit (§ 14 days Post Implant) ..................................................... 15
4.7.3.
Visits 3 and 4: 90 ± 30 Days and 180 ± 30 Days Post Activation............................ 16
4.7.4.
Visit 5: 1 year ± 60 Days Post Activation................................................................. 16
4.7.5.
Visit 6: 2 years ± 60 Days Post Activation ............................................................... 17
4.7.6.
Unscheduled Visits .................................................................................................. 17
4.8
Sample Size Rationale ............................................................................................ 18
4.9
Informed Consent.................................................................................................... 18
4.9.1
Obtaining Informed Consent.................................................................................... 18
4.9.2
Requirements for Informed Consent........................................................................ 19
4.10
Subject Data Confidentiality..................................................................................... 19
5
Risks and Benefits .......................................................................................... 19
6
Registry Management ..................................................................................... 20
6.1
Procedures to Amend the Registry Protocol............................................................ 20
6.2
Sponsor Responsibilities ......................................................................................... 20
6.3
Role of the Sponsor Representatives ...................................................................... 20
6.4
Investigators............................................................................................................ 21

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Document Number 950066, Rev. G
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6.4.1
Record Keeping ....................................................................................................... 21
6.5
Publications............................................................................................................. 21
6.6
Registry Monitoring.................................................................................................. 22
6.7
Registry Completion ................................................................................................ 22
6.8
Suspension or Premature Termination of the Registry............................................. 22
6.9
Name and Address of the Sponsor.......................................................................... 22
6.10
Statements of Compliance....................................................................................... 22
Appendix 1: Acronyms and Definitions ............................................................... 23
Appendix 2: Bibliography...................................................................................... 24
Table of Tables
Table 1: Safety Reporting Definitions.................................................................................. 11
Table 2: Adverse Event Relatedness Categories ................................................................ 12
Table 3: Data Collection Schedule ...................................................................................... 18

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Document Number 950066, Rev. G
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1.
Registry Summary
Registry Purpose
To gather data on the long-term safety of ReActiv8 and identify any residual 
risks by reporting all Serious Adverse Device Effects as well as performance 
and health care utilization through two years post-implant.
Indications For 
Use
ReActiv8 is an adjunct to medical management of Chronic Low Back Pain for 
relief of pain in adults who have attempted at least medical management and 
physical therapy.
Registry Device
ReActiv8
Registry Design
The ReActiv8 Registry is an international, multi-center, data collection registry 
in Subjects who meet the CE Mark indications and are not contraindicated for 
ReActiv8. A minimum of 50 Subjects will be implanted at up to 25 sites. 
Subjects will be followed for two years post-implant, at which point they will 
be exited from the Registry.
Population
A minimum of 50 Subjects will be implanted at up to 25 sites. 
Enrolment 
Criteria
Inclusion Criteria
x
Meet the Indications for ReActiv8
x
Willing to sign the Informed Consent for the ReActiv8-C Post-Market 
Surveillance Registry
x
Age  18 years
Exclusion Criteria
x
Contraindicated for ReActiv8
Safety, 
Performance, 
Health Utilization
Measures
Safety
x
Assessment of all Serious Adverse Device Effects that occur through 
two years post-implant.
Performance
x
Change in average low back pain from baseline to follow-up visits 
(NRS)
x
Change in Oswestry Disability Index from baseline to follow-up visits 
(ODI)
x
Change in EQ-5D from baseline to follow-up visits (EQ-5D)
x
Assessment of Percent Pain Relief at follow-up visits (PPR)
x
Assessment of Subject Global Impression of Change at follow-up
visits (SGIC)
x
Assessment of Patient Treatment Satisfaction at follow-up visits 
(TSQ)
Health Care Utilization
x
Change in work status from baseline to follow-up visits
x
Change in use of opioids from baseline to follow-up visits
x
Assessment of Health Care Utilization (office visits, hospital visits, 
imaging and diagnostics and other pain management treatments) at
follow-up visits
Study Visit 
Schedule
x
Visit 1: Baseline visit
x
Visit 2: Activation visit: Approximately 14 days post-surgery
x
Visit 3: 3 month visit: 90±30 days post-activation
x
Visit 4: 6 month visit: 180±30 days post-activation
x
Visit 5: 1 year visit: 1 year±60 days post-activation
x
Visit 6: 2 year visit: 2 year±60 days post-activation

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Document Number 950066, Rev. G 
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2.
Background
Mainstay Medical has developed an implantable medical device designed as therapy for 
people with chronic low back pain (CLBP). The device, called ReActiv8®, consists of two 
implantable leads with four electrodes each, configured to deliver electrical stimulation to the 
medial branch of the dorsal ramus nerves as they cross the transverse process at L3 to elicit 
bilateral contraction of the lumbar multifidus muscles (MF). The leads are coupled to a
battery powered implantable pulse generator (IPG) which is activated by an external 
Activator and is programmed using Application Software provided on a laptop computer.
Several accessories are included as part of the system, for example to facilitate the surgical 
procedure.
The therapy delivered by the ReActiv8 was explored with a European Feasibility Study in 
2011 to 2013 using “off the shelf” general purpose neurostimulation devices from other 
manufacturers, and results have been published.1
ReActiv8 was investigated under an ongoing clinical trial at nine sites in Australia and 
Europe (ReActiv8-A). The data from the first 47 Subjects implanted with ReActiv8 in this trial 
served as the basis for CE Marking on 24-May-2016. A summary of the ReActiv8-A Trial can 
be found at http://clinicaltrials.gov/show/NCT01985230.
2.1. Chronic Low Back Pain 
Low back pain is usually defined as pain and discomfort, localized below the costal margin 
and above the inferior gluteal fold, with or without referred leg pain.2,3 Chronic Low Back 
Pain (CLBP) is usually defined as back pain for at least 3 months. The NIH Task Force on 
Research Standards for Chronic Low Back Pain recommended4 that Chronic Low Back Pain 
be defined as a back pain problem that has persisted for at least 3 months and has resulted 
in pain on at least half the days in the past 6 months.
Chronic low back pain is a major health problem, and the World Health Organization reports 
that “Low back pain is the most prevalent of musculoskeletal conditions; it affects nearly 
everyone at some point in time and about 4–33% of the population at any given point.”5
There are many publications on the epidemiology6 of back pain including prevalence,7,8,9
natural history, demographics, and country by country variability.
People with acute low back pain and associated disability usually improve rapidly within 
weeks, but pain and disability typically continue, and recurrences are common.10 Although 
most episodes of acute back pain resolve within 3 months, “recovery after 12 weeks is slow 
and uncertain. Fewer than half of those individuals disabled for longer than 6 months return 
to work and, after 2 years of absence from work, the return-to-work rate is close to zero.”11
Like many chronic conditions, the costs are driven by the small proportion of the population 
who have been sick for the longest period – for back pain, patients with disability >1 year 
account for 5% of cases, but 65% of costs.12,13
Although there has been a lot of attention and investment applied to surgical treatments for 
low back pain, only approximately 20% of patients are suitable surgical candidates.14 The
remaining patients are sometimes referred to as having “non-specific low back pain” 
(NSLBP) or “axial low back pain” (ALBP). There are European clinical practice guidelines for 
chronic NSLBP2 and UK guidelines for management of patients with persistent CLBP 
(published by the National Institute for Clinical Excellence - NICE).15 US guidelines for acute 
and chronic low back pain are similar to the European guidelines.16
Exercise therapy is frequently prescribed for NSLBP, but the effectiveness of exercise 
therapy for acute back pain is negligible.17 Systematic reviews of the literature18,19
concerning therapies for chronic low back pain show that exercise is generally ineffective, 

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other than certain types of exercise therapy which can be effective in a small subset of 
patients.
Many non-invasive therapies have been tried with modest or no success, and several 
reviews are available.20 Therapies include lumbar extensor strengthening exercises;21
watchful waiting (i.e., no therapy),22 traction therapy,23 the McKenzie Method of exercise 
therapy,24 various types of energy application including ultrasound, TENS,25 osteopathic 
therapy,26 and thermotherapy,27 and lumbar stabilization exercises.28
“Usual care” or “conventional medical management” for CLBP usually consists of coping 
mechanisms for pain, and pain medications (often opioids), which are often increased during 
the episodic flare-ups of pain.
2.2. ReActiv8
Arthrogenic muscle inhibition (AMI)29 is the physiological mechanism by which pain in a 
skeletal joint disrupts the motor control to the muscles that stabilize the joint – often 
observed in the quadriceps post knee surgery. A similar mechanism underlies some types of 
chronic low back pain, with disruption to the motor control of the key stabilizing muscles –
the lumbar multifidus. Evidence includes diminished EMG activity in back pain patients30 and
delayed reflex response of the MF to perturbations.31 Pain alters the magnitude of activation 
of deep MF during certain types of activity.32 Ultrasound imaging evidence of reduced neural 
drive in back pain patients includes diminished cross sectional area with contraction,33
reduced ability to cause a muscle thickness change on command,34 and altered contraction 
patterns with changes in posture.35
Published studies show that subject initiated contraction of the lumbar multifidus with 
ultrasound guided biofeedback motor control physical therapy exercises can lead to 
improvements in back pain, but this approach has not been adopted due to practical 
challenges, economic difficulties, and patient compliance issues. The mechanism of action is 
believed to be restoration of motor control of the lumbar multifidus, thereby leading to 
rehabilitation of the muscle, improved spine stability and reduction in back pain.
Electrical stimulation to restore motor control has been successfully used with other skeletal 
muscles. In particular, stimulation via superficial (skin) electrodes over the motor point of the 
quadriceps can restore neural drive and allow rehabilitation of the muscle in patients 
following total knee arthroplasty36 or other surgical procedures.37,38 Painful knee 
osteoarthritis can be treated without surgery but may also lead to pain mediated inhibition of 
neural drive to the quadriceps, which can be treated effectively with electrical stimulation.39
ReActiv8 has been designed to incorporate the principles of these prior approaches. 
Electrical stimulation of the medial branch of the dorsal ramus nerve that innervates the 
lumbar multifidus is delivered episodically (in a stimulation session of 10 seconds on 20 
seconds off, for 30 minutes, twice per day).

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Document Number 950066, Rev. G
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3.
ReActiv8 Therapy
3.1. Summary of ReActiv8
ReActiv8 is a CE Marked implantable electrical stimulation system consisting of the following 
components: 
1. Implantable Pulse Generator (IPG) – (pre-loaded with IPG Firmware Code and 
packaged with a Torque Wrench to aid in implant procedure)
2. Percutaneous Leads (with Stylet and Suture Sleeves)
3. Application Software
4. Programmer Wand
5. Activator (pre-loaded with Activator Firmware Code)
6. Magnet
7. Tunneler
The ReActiv8 Programmer Wand and Application Software are provided with a commercially 
available laptop computer and AC adapter. Commercially available surgical tools such as a 
7Fr Introducer Kit is used at implant and is not part of ReActiv8.
ReActiv8 delivers stimulation via electrodes placed adjacent to the medial branch of the 
dorsal ramus nerve at the preferred location as it crosses the L3 transverse process. The 
electrodes are located at the distal end of a Stimulation Lead that is connected to an 
implantable pulse generator (IPG) placed in a surgical pocket typically above the buttocks (in 
a place similar to that used in Spinal Cord Stimulation implants). Two leads are placed (one 
each left and right side) and connected to the IPG. The IPG is externally programmable via 
Application Software stored on a laptop computer. Stimulation is manually initiated by an 
external device (Activator) and can be stopped with the Activator or Magnet.
The leads incorporate a fixation mechanism that consists of two sets of 3 point tines – one 
set facing forward and one set facing backwards. The tines are positioned to lie on either 
side of the intertransversarii lateralis, thus reducing the risk of lead migration by either 
advancement or retraction. The lead body is a polyurethane tube containing the lead 
conductor, incorporating a lumen to allow passage of a stylet. Refer to the Implant and 
Programming Manual for more detail on device specifications and operation.
3.1.1.
Implantable Components of ReActiv8
The ReActiv8 IPG, and the two sizes of leads (45 cm and 65 cm), plus suture sleeves, are 
designed for permanent implant. The implantable components of ReActiv8 are supplied 
sterile, and are intended for single use only.
x
Model 5100 ReActv8 Implantable Pulse Generator (“IPG”) pre-loaded with Firmware 
Code 
x
Model 8000-45 ReActiv8 Percutaneous Lead, 45 cm length (“Lead”)
x
Model 8000-65 ReActiv8 Percutaneous Lead, 65 cm length (“Lead”)
x
Model 8145 ReActiv8 Percutaneous Lead, 45 cm length (“Lead”)
x
Model 8165 ReActiv8 Percutaneous Lead, 65 cm length (“Lead”)
3.1.2.
Non-Implantable Components of ReActiv8
The Torque Wrench and Stylet are provided to facilitate implantation of the IPG and leads. 
The Application Software and Programmer Wand are used with a laptop computer to 
communicate with the IPG in order to program the IPG operational mode and settings, read 
history data from the IPG, and obtain IPG and lead status information. The Activator is used 

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to initiate and/or suspend stimulation. The Magnet is used to enter Magnet Mode (with 
Magnet Mode operation determined by the programmed parameters of the IPG).
The non-implantable components of the ReActiv8 system are:

Model 7000 ReActiv8 Activator (“Activator”) with Firmware Code

Model 4000 ReActiv8 Magnet (“Magnet”)

Model 5500 Torque Wrench (“Torque Wrench”)

Version 1.0.1.6 (English) and 1.0.1.9 (Multilanguage) Application Software

Model 6000 Programmer Wand (“Wand”)

Model TUN1 Mainstay Tunneler (“Tunneler”)
The ReActiv8 Programmer Wand and Application Software are provided with a 
commercially available laptop computer and AC adapter.
3.2. Indications for Use
ReActiv8 is an adjunct to medical management of Chronic Low Back Pain for relief of pain in 
adults who have attempted at least medical management and physical therapy.
3.3. Contraindications
ReActiv8 is contraindicated for patients who are:
x
Unable to operate the system
x
Unsuitable for ReActiv8 implant surgery
3.4. Surgical Implantation and Device Activation
The surgical implantation procedure, device programming, and use by the Subject are per
the Implant and Programming Manual and the User Manual.
In normal use, following implantation and a suitable recovery period, the IPG is programmed 
to deliver stimulation that elicits smooth contraction of the lumbar multifidus. Typical 
parameters are 0.5 mA, 200 ȝV  Hz, with a duty cycle of 10 seconds on and 20 seconds 
off, delivered for a Session of 30 minutes.
To start a Session, it is recommended that the Subject is positioned comfortably prone or 
lying on the side. The Subject initiates delivery of electrical stimulation with the Activator, 
which can also be used to stop stimulation (e.g.: in case of interruption). Two sessions of 
stimulation, each of 30 minutes, are delivered each day (e.g. morning and evening).
3.5. Physician and Health Care Personnel Training
All physicians who will implant any portion of the ReActiv8 system in the ReActiv8 Registry
must have participated in product training. The Sponsor will document completion of training 
for each implanting physician.
All physicians and other health care personnel who will interact with the programming 
system will receive training from the Sponsor, which includes lectures and use of a 
programming system with a simulator. This training will also include interaction with the 
Activator and Magnet handled by the Subject.

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4.
Registry Design
4.1. Objective
To gather data on the long-term safety of ReActiv8 and identify any residual risks by 
reporting all Serious Adverse Device Effects as well as performance and health care 
utilization through two years post-implant.
4.2. Overview
The ReActiv8 Registry is an international, multi-center, data collection registry in Subjects 
who meet the CE Mark indications and are not contraindicated for ReActiv8. A minimum of 
50 Subjects will be implanted at up to 25 sites. Subjects will be followed for two years post-
implant, at which time they will be exited from the Registry. Subjects may decide to be 
enrolled in the registry before or after implant so that information on the performance of the 
system can be collected.
4.3. Enrolment Criteria
4.3.1.
Inclusion Criteria
In order to be included in this Registry, Subjects must meet the following inclusion criteria:
1. Meet the Indications for ReActiv8
2. Willing to sign the Informed Consent for the ReActiv8-C Post-Market Surveillance 
Registry
3. $JH   \HDUV
4.3.2.
Exclusion Criteria
Subjects will be excluded from the Registry if they are contraindicated for ReActiv8.
4.4. Safety Reporting
4.4.1.
Adverse Events
All adverse events will be collected during this registry.  Safety definitions used during this 
Registry will be per the definitions in ISO 14155 and are provided in Table 1 and Table 2.
Table 1: Safety Reporting Definitions
Adverse Event
Any untoward medical occurrence, unintended disease or injury, 
or untoward clinical signs (including abnormal laboratory findings) 
in subjects, users or other persons, whether or not related to the 
study device
NOTE For users or other persons, this definition is restricted to 
events related to the study device.
Adverse Device Effect
Adverse event related to the use of the study device
NOTE 1 This definition includes adverse events resulting from 
insufficient or inadequate instructions for use, 

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4.6. Health Care Utilization
Cost-effectiveness data will be collected for ReActiv8 at baseline and the annual visits post-
activation, to be extrapolated to the lifetime of the device. The key economic outcome 
measures to be recorded will be:
1. Work status
2. Use of Opioids
3. Health Care Utilization (office visits, hospital visits and other therapies such as 
physical therapy)
4.7. Data Collection Schedule
The data for the registry will be collected according to the following schedule: 
Visit 1:
Baseline visit
Visit 2:
Activation visit (approximately 14 days post-surgery) 
Visit 3: 
90±30 days Post-Activation
Visit 4:
180±30 days Post-Activation
Visit 5:
1 year±60 days Post-Activation
Visit 6:
2 years ±60 days Post Activation
The above mentioned visits are part of the standard of care for patients with this type of 
treatment. The given time windows are advisable and data collection outside these windows 
will not be seen as a protocol deviation.
Any unscheduled visits will be recorded as stated in Table 3 and in section 4.7.6.
Note that data collection of all performance measures shall be done as the first thing in the 
follow up visit, prior to any other procedures.
Note that once a Subject has consented to participate in the Registry Adverse Events will be 
collected at each visit.
4.7.1.
Visit 1: Baseline Visit
The process for obtaining informed consent shall be in compliance with ISO 14155.
If the subject agrees to participate in the registry for data collection, the Subject Informed 
Consent will be signed and recorded in the Subject’s records at Visit 1. The Subject will be 
assigned a unique Registry identifier and will be asked to complete the baseline 
questionnaires.
Data will be collected according to the data collection schedule (Table 3).
4.7.2.
Visit 2: Activation Visit (§ 14 days Post Implant)
Activation of the therapy shall be about 14 days from the date of implant surgery.

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If the Subject is unable to use the device for any reason (e.g.: injury, infection, other new 
clinical condition) at the time of the activation visit, then the activation visit may be postponed 
to allow the issue to resolve. This will not be considered a deviation. 
Activities to be performed:
x
Perform electrode impedance and threshold measurements and record results 
x
Program IPG
x
Train the Subject in use of the Activator, and document assessment of Subject’s 
ability to self-administer therapy. Instruct Subject on timetable of therapy delivery 
(i.e.: twice a day starting the next day).
x
Train the Subject in the procedure to deliver stimulation, including time of day and 
Subject positioning.
Data will be collected according to the data collection schedule (Table 3).
4.7.3.
Visits 3 and 4: 90 ± 30 Days and 180 ± 30 Days Post 
Activation 
During this visit data will be collected according to the data collection schedule (Table 3) and 
the following activities will be performed: 
Device activities (if applicable):
x
Electrode impedance and threshold measurements
x
Readout from IPG of therapy delivery times and duration
x
Adjustment of stimulation configuration and amplitude as appropriate
If a subject is unable to return to the clinic for an annual office visit, the clinical site may send 
the questionnaires to the subject for completion and a telehealth visit may be completed by 
the investigator and study coordinator.  
Device interrogation and programming will be done at a later date when the subject is able to 
return for a visit.  
If programming is completed it will be entered on the annual visit form. It will not be a 
deviation when the interrogation and programming of the system is required at a later date.
4.7.4.
Visit 5: 1 year ± 60 Days Post Activation
During this visit data will be collected according to the data collection schedule (Table 3) and 
the following activities will be performed: 
Device activities (if applicable):
x
Electrode impedance and threshold measurements
x
Readout from IPG of therapy delivery times and duration
x
Adjustment of stimulation configuration and amplitude as appropriate
If a subject is unable to return to the clinic for an annual office visit, the clinical site may send 
the questionnaires to the subject for completion and a telehealth visit may be completed by 
the investigator and study coordinator.  
Device interrogation and programming will be done at a later date when the subject is able to 
return for a visit.  

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If programming is completed it will be entered on the annual visit form. It will not be a 
deviation when the interrogation and programming of the system is required at a later date.
4.7.5.
Visit 6: 2 years ± 60 Days Post Activation
During this visit, data will be collected according to the data collection schedule (Table 3)
and the following activities will be performed: 
Device activities (if applicable):
x
Electrode impedance and threshold measurements
x
Readout from IPG of therapy delivery times and duration
x
Adjustment of stimulation configuration and amplitude as appropriate
If a subject is unable to return to the clinic for an annual office visit, the clinical site may send 
the questionnaires to the subject for completion and a telehealth visit may be completed by 
the investigator and study coordinator.  
Device interrogation and programming will be done at a later date when the subject is able to 
return for a visit.  
If programming is completed it will be entered on the annual visit form. It will not be a 
deviation when the interrogation and programming of the system is required at a later date.
4.7.6.
Unscheduled Visits
If an unscheduled visit occurs for any reason, the following data will be collected prior to any 
other activities.
x
Low Back Pain NRS (average low back pain in the last 24 hours)
x
Report  Adverse Events (if applicable)
x
Complete and document device activities if applicable
Data will be collected according to the data collection schedule (Table 3).

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Table 3: Data Collection Schedule
1: Baseline Visit
2: Activation Visit 
about 14 Days Post-
Surgery
3: 90±30 Days Post 
Activation
4: 180±30 Days 
Post Activation
5: 1 Year ±60 Days 
Post Activation
6: 2 Year ±60 Days 
Post Activation
Unscheduled Visit
Medical History including Pain Detect Questionnaire
9
Low Back Pain (NRS)
9
9
9
9
9
9
9
ODI
9
9
9
9
9
EQ-5D
9
9
9
9
9
Percent Pain Relief (PPR)
9
9
9
9
Subject Global Impression of Change (SGIC)
9
9
9
9
Treatment Satisfaction Questionnaire (TSQ)
9
9
9
9
Work Status Evaluation
9
9
9
9
9
Medications: Opioids
9
9
9
9
9
Health Care Utilization
9
9
9
Device Measurements & Stimulation Thresholds*
9
9
9
9
9
9
Adverse Events (AE’s)
9
9
9
9
9
9
*Device information will be collected at the implant procedure. 
4.8
Sample Size Rationale
The sample size was based on the desire to gain a sufficient amount of representative data 
with the device in the market-released setting. In order to more fully characterize the 
experience with the system and detect rare events, the sample size of 50 Subjects provides 
80% power to observe the incidence of at least one rare event for any events occurring at a 
population rate as low as 3.2%.
4.9
Informed Consent
4.9.1
Obtaining Informed Consent 
Informed Consent is required from all Subjects (or their legal representatives) prior to the 
Subject’s participation in the Registry. The process of obtaining Informed Consent shall 
comply with the Declaration of Helsinki 2004 (amendment Fortaleza, Brazil, October 2013),
ISO 14155 and applicable national regulations, as applicable.
The process of obtaining informed consent shall
a) Avoid any coercion of or undue influence of Subjects to participate,
b) Not waive or appear to waive Subject’s legal rights,
c) Use native language that is non-technical and understandable to the Subject or 
his/her legal representative,
d) Provide adequate time for the Subject to consider participation and ask questions if 
necessary,
e) Informed consent shall always be signed and personally dated by the Subject or legal 
representative and by the health personnel as required by the Ethics Committee.
The original signed Informed Consent must be retained on file by the Investigator and a copy 
given to the Subject (Investigator’s responsibility).

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4.9.2
Requirements for Informed Consent
The Sponsor will provide the recommended Subject Informed Consent Form template. The 
Ethics Committee (EC) may alter or amend the text as appropriate, but the EC and the 
Sponsor must approve the final text of the informed consent before Subject enrolment can 
begin. After the information contained in the informed consent document has been reviewed 
with each Subject, the Subject and the investigator (or appointed designee) must sign and 
date the Informed Consent Form. A signed informed consent indicates the Subject’s 
willingness to participate in the Registry prior to the subject’s participation in the Registry.
4.10 Subject Data Confidentiality 
Throughout the Registry, confidentiality shall be maintained at all times, by all parties 
involved, and all data shall be secured against unauthorized access. Confidentiality of each 
Subject shall be preserved in reports and any publication of the results. Only authorized 
personnel and their designees will have access to these confidential files. Subject data may 
be made available to national and foreign regulatory agencies, health or other governmental 
authorities, under strict confidentiality condition and taking into account the applicable data 
protection laws. The sites shall ensure that data (e.g. worksheets, laptop computer printouts, 
medical records, digital images) forwarded to the Sponsor do not contain any Subject 
identifying data (such as name and birth date) other than the Subject ID.
Source documents as per ISO 14155 are printed, optical or electronic documents including 
the information in original records and necessary for the reconstruction and evaluation of the 
data. Original source data should remain at the site.
Any changes of the reported data should be reported to the Sponsor. A participating 
Investigator shall provide direct access to source data and documents for Registry-related 
monitoring, audits, Ethics Committee review, and regulatory inspection.
Subjects’ health information will be kept confidential in accordance with applicable laws and 
regulations. Subjects’ health information may be used to conduct this Registry, as well as for 
additional purposes, such as overseeing and improving the performance of products, new 
medical research and proposals for developing new medical products or procedures. 
Information received during the Registry will not be used to market to Subjects.
5
Risks and Benefits
All risks and benefits are identical to the CE Marked product. These are listed in the Implant 
and Programming Manual (990002-001), the User Manual (990003-001) and in the subject
information (consent form).

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6
Registry Management
6.1
Procedures to Amend the Registry Protocol 
From time to time, an Investigator or the Sponsor may propose changes to the Registry
Protocol. The Sponsor shall have final authority to make such changes or not.
In all cases of changes to the Registry Protocol, the local rules for approval of modifications 
shall be followed, including by way of example a submission to the Ethics Committee (either 
in full or to the Chairman), and modifications to the Registry Agreement with the institution if 
applicable.
6.2
Sponsor Responsibilities
Mainstay Medical Limited is the Sponsor of the ReActiv8-C Registry. It is the responsibility of 
the Sponsor to ensure proper monitoring of the Registry and to see that all clinical 
requirements are met. In addition, Sponsor representatives may participate in the conduct of 
the Registry to the extent described in the following section on the role of the Sponsor 
representatives. Participation in the Registry will be limited to Sponsor personnel who are 
appropriately qualified and trained.
It is the responsibility of the Sponsor to ensure appropriate training of all individuals involved
in the Registry. This includes investigators and other health care professionals at the sites, 
Sponsor personnel, and contractors if applicable.
6.3
Role of the Sponsor Representatives 
Sponsor representatives can provide technical support to the Investigator and other health 
care personnel (collectively HCP) as needed during implant, and testing. Support may 
include HCP training, addressing HCP questions, or providing clarifications to HCPs 
concerning the operation of equipment supplied by Mainstay Medical (including laptop 
computers and other support equipment) or the data related to the Registry.
At the request of the Investigator and while under the Investigator’s supervision, Sponsor
representatives may operate equipment during implant or follow-up visits, assist with the 
conduct of testing, and interact with the Subject to accomplish requested activities.
Typical tasks may include:
x Interrogating the device or programming device parameters to physician requested 
settings
x Performing lead diagnostic testing using a laptop computer to obtain thresholds and 
impedance measurements
x Clarifying device behavior, operation or diagnostic output as requested by the 
Investigator or other health care personnel
x Assisting with the collection of Registry data from laptop computers and other 
equipment
x Entering data on Registry worksheets as long as the responsible Registry Investigator 
verifies and signs the completed worksheet
x Observing testing or medical procedures to provide information relevant to the Registry 
x Reviewing collected data and Registry documentation for completeness and accuracy
At no point shall Sponsor representatives:
x Practice medicine;
x Discuss with the Subject the Subject’s diagnosis or recommend treatment;
x Enter data onto the CRF; or
x Discuss the Study with the Subject.

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6.4
Investigators
The Investigator is responsible for protecting the rights, safety, and welfare of Subjects
under the Investigator’s care. The Investigator is also responsible for ensuring that informed 
consent is obtained in accordance with this Registry, applicable regulatory requirements, 
and Ethics Committee requirements. The Investigator or co-Investigator may request the 
presence of Sponsor representatives at device-related procedures.
6.4.1
Record Keeping
Investigators are required to maintain on file the accurate, complete, and current records 
relating to this Registry:
x
All correspondence with another Investigator or Ethics Committee, Mainstay Medical, 
a monitor, including required reports
x
The signed Registry Protocol with any and all amendments
x
The approved template of the Subject informed consent form
x
Ethics Committee approval of the Registry Protocol and any amendments and 
renewals
x
The Registry Agreement
x
The Implant and Programming Manual and any other documents provided with the 
device
x
Current curriculum vitae for the principal Investigator and all sub-investigators
x
Monitoring letters (if applicable)
x
Interim/final reports
x
Registry initiation forms
x
Registry closure documents
In addition, to the Registry administrative documents, Subject records shall be appropriately 
filed, including the following:
x
Signed informed consent forms
x
Source documents used for recording data (e.g., telephone visit documentation,
device characteristics at implant and follow-up)
x
All AEs
x
Records of any SADE, including supporting documentation
x
Records pertaining to Subject deaths during the Registry
x
Relevant source data
x
Any other records required by the Sponsor
6.5
Publications
Should a presentation or publication be contemplated, the Sponsor shall be provided with 
copies of any abstracts, papers or manuscripts for review and approval within a reasonable 
period prior to submittal for publication or presentation. The Sponsor shall limit its review to a 
determination of whether Confidential Information is disclosed and shall not attempt to 
censor or in any way interfere with the presentation or publication beyond the extent 
necessary to protect Confidential Information or to allow the Sponsor to protect its rights in 
patentable or copyrightable material.
Authorship of publications shall follow the recommendations of the International Committee 
of Medical Journal Editors*, which may result in employees of the Sponsor being included as 
authors.
*
http://www.icmje.org/ethical_1author.html

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6.6 Registry Monitoring 
Monitoring will be performed at least annually at each site during the Registry to ensure that 
compliance with applicable regulations are maintained. Monitors are individuals who are 
designated to oversee the progress of a Registry. These individuals are appropriately trained 
and qualified to monitor the progress of a Registry. Monitors will be selected and assigned 
by Mainstay Medical.
At times throughout the study, remote monitoring may be required. If performed, it will be 
done in compliance with the country, EC and clinical site requirements.   
6.7 Registry Completion
The Sponsor will notify each Investigator of the completion or termination of the Registry or 
of the Investigator's participation in the Registry. 
6.8
Suspension or Premature Termination of the Registry 
If suspicion of an unacceptable risk to Subjects arises during the Registry, or when so 
instructed by the Ethics Committee, or regulatory authorities, the Sponsor shall suspend the 
Registry while the risk is assessed. The Sponsor shall terminate the Registry if an 
unacceptable risk is confirmed.
If the Sponsor makes a decision to discontinue the Registry for any reason (e.g., significant 
change in risk/benefit due to unanticipated adverse device effect, or other scenario), then the 
Sponsor will promptly inform all Investigators, Ethics Committees, and relevant regulatory 
bodies.
6.9
Name and Address of the Sponsor
Mainstay Medical Limited
Clonmel House
Swords,
County Dublin,
K67F2K3
Ireland
Sponsor’s Contact:
Clinical Affairs
Mainstay Medical
Phone: 877 702-8488
Email: clinical@mainstaymedical.com
6.10 Statements of Compliance
This Registry shall be conducted in accordance with the ethical principles that have their 
origin in the Declaration of Helsinki.
The Registry shall not begin until the required approval or favorable opinion from the Ethics 
Committee and any other regulatory body as appropriate and necessary. Any additional 
requirements imposed by the Ethics Committee shall be followed, if appropriate.

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consent from Mainstay Medical and are not to be used in any unauthorised way.
Page 23 of 24
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Appendix 1: Acronyms and Definitions
ADE
Adverse Device Effect - adverse event related to the use of the study device 
AE
Adverse Event - any undesirable clinical occurrence that affects the health or 
safety of the Subject  
ALBP
Axial Low Back Pain
AMI
Arthrogenic Muscle Inhibition – the physiological mechanism by which pain in a 
skeletal joint can inhibit activation of the muscles that surround or stabilize that 
joint
CLBP
Chronic Low Back Pain
CRF
Case Report Form(s) - set of documents for each Subject on which information
to be reported to the Sponsor is recorded
CRO
Contract Research Organization - person or organization contracted by the 
Sponsor to perform one or more of the Sponsor's clinical investigation-related 
duties and functions (ISO 14155) 
CV
Curriculum vitae
EC
Ethics Committee - independent body whose responsibility it is to review the 
registry in order to protect the rights, safety and well-being of human subjects 
participating in the Registry
EMG
Electromyogram
HCP
Health Care Personnel
ICMJE 
International Committee of Medical Journal Editors
IFU
Instructions for Use
IPG
Implantable Pulse Generator
MF
Multifidus muscle of the lumbar spine  
NSLBP
Non-Specific Low Back Pain
PI
Principal Investigator. A qualified physician who takes overall responsibility for 
conduct of the Registry according to the protocol and regulations.
SADE
Adverse device effect that has resulted in any of the consequences characteristic 
of a serious adverse event
SAE
Serious Adverse Event. An adverse event that
a)
led to death,
b)
led to serious deterioration in the health of the subject, that either resulted in
1. a life-threatening illness or injury, or
2. a permanent impairment of a body structure or a body function, or
3. in-patient or prolonged hospitalization, or
4. medical or surgical intervention to prevent life-threatening illness or injury
or permanent impairment to a body structure or a body function,
c)
led to fetal distress, fetal death or a congenital abnormality or birth defect.
NOTE This includes device deficiencies that might have led to a serious adverse
event if a) suitable action had not been taken or b) intervention had not been
made or c) if circumstances had been less fortunate. These are handled under
the SAE reporting system.
TENS
Transcutaneous Electrical Nerve Stimulation
USADE
Unanticipated serious adverse device effect

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Page 24 of 24
Document Number 950066, Rev. G
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