Intended Purpose/Indication for ReActiv8

The ReActiv8 System is indicated for bilateral stimulation of the medial branch of the dorsal ramus as an aid in the management of mechanical chronic low back pain associated with multifidus muscle dysfunction, in adults who have failed therapy including pain medications and physical therapy and are not candidates for spine surgery.


ReActiv8 is contraindicated for patients who are: 

Unsuitable for ReActiv8 implant surgery, for reasons such as: 

Possible benefits of ReActiv8

The possible benefits associated with ReActiv8 include: 

*For details related to the possible benefits of ReActiv8, refer to the ReActiv8 Summary of Safety and Clinical Performance (SSCP). A copy of the SSCP) can be viewed by searching the device brand name on the Eudamed website at, when it is available. A copy of the SSCP is also available at

Electromagnetic Interference (EMI) – Electromagnetic interference from electrical or magnetic fields generated by equipment found in the home, work, medical or public environments may interact with or disrupt the function and operation of the ReActiv8 System. The ReActiv8 system includes features that provide a measure of protection from EMI, and most electrical devices and magnets encountered in a normal day are unlikely to affect the operation of the system. However, sources of strong EMI can result in the following effects:


EMI from the following medical procedures or equipment may damage the device, interfere with device operation, or cause harm to the patient. If these procedures are required, follow the guidelines below.

Diathermy therapy – Safety of diathermy with an implanted ReActiv8 System has not been evaluated. Do not use short-wave diathermy, microwave diathermy, or therapeutic ultrasound diathermy (all now referred to as diathermy) on patients implanted with a ReActiv8. Energy from diathermy can be transferred through the implanted system and cause tissue damage at the location of the implanted leads, resulting in severe injury or death. 


Diathermy should not be used because it may damage the IPG components. This damage could result in loss of function, requiring additional surgery. Injury or damage can occur during diathermy treatment whether the system is turned on or off. All patients should be advised to inform their healthcare professionals that they should not be exposed to diathermy treatment. 

Magnetic resonance imaging (MRI) – MRI compatibility of the ReActiv8 system is conditional on imaging parameters. Refer to the ReActiv8 System Magnetic Resonance Imaging (MRI) Guidelines.

MRI Safety Information

Magnetic Resonance Imaging (MRI) 

The ReActiv8 Implantable Pulse Generator (IPG) and implantable leads are MR Conditional devices with demonstrated safety in the MR environment only within specified conditions.

Consult with your healthcare provider prior to an MR exam and inform MRI site personnel that they have an MR Conditional medical device during MR screening prior to the MR exam.

Refer-to-instruction-manual/booklet Refer to the document ReActiv8 System Magnetic Resonance Imaging (MRI) Guidelines for an up-to-date list of approved MR Conditional components, model numbers and required conditions (including patient preparation) for safe use in the MR Environment. Referring to this document prior to an MRI scan is mandatory.


Failure to follow these guidelines for MRI scans may result in severe patient injury and/or device malfunction.

Defibrillation/cardioversion – When a patient is in ventricular or atrial fibrillation, the first consideration is patient survival. External defibrillation or cardioversion can damage the ReActiv8 IPG. It may also cause induced currents in the leads that can injure the patient. Minimize the current flowing through the ReActiv8 system by following these guidelines: 

Electrocautery and radio frequency (RF) ablation – Electro-surgery devices should not be used in close proximity to the ReActiv8 IPG or Lead(s). Contact between a lead and the electrosurgical instrument can cause direct stimulation of a nerve and can result in severe injury to the patient. Electro-surgery devices may also damage the lead or IPG and cause a loss of stimulation. 

If electrosurgical cautery or RF ablation cannot be avoided, observe the following precautions to minimize complications: 

  1. Program the ReActiv8 IPG Mode to OFF. 
  2. Avoid direct contact between the cautery equipment or ablation catheter and the implanted ReActiv8 IPG or Leads. 
  3. Use a bipolar electro-cautery system if possible. 
  4. Use short, intermittent bursts at the lowest possible energy levels. 
  5. Verify proper operation of the ReActiv8 System and perform a stimulation test immediately following the procedure. If an anomaly is detected, corrective actions may include lead repositioning or replacement and/or device reprogramming or replacement. 

ReActiv8 interaction with other active implantable devices – Safety of the ReActiv8 System has not been evaluated when used in combination with active implantable devices (e.g., pacemaker, defibrillator, spinal cord stimulation). There may be undesirable interactions between the stimulation pulses of the ReActiv8 System and the other active implantable device. In the event of a patient requiring both a ReActiv8 System and an active implantable device, physicians involved with both devices (e.g., neurologist, neurosurgeon, cardiologist, cardiac surgeon) should discuss the possible interactions between the devices before surgery. 


Case damage – If the ReActiv8 IPG case is pierced or ruptured, severe burns could result from exposure to battery chemicals. 


Electromagnetic Interference (EMI) Guidelines

EMI from the following equipment is unlikely to affect the ReActiv8 System if the guidelines below are followed: 

If it is suspected that equipment is interfering with ReActiv8, the following is recommended: 

  1. Move away from the equipment or object. 
  2. If possible, turn OFF the equipment or object. 
  3. Then, if necessary, use the Magnet or Activator to disable stimulation. 
  4. Inform the equipment owner or operator of the occurrence. 

If the above actions do not resolve the effects of the interference, or there is a suspected change after exposure to EMI, then the patient should contact their physician. 

If magnetic fields cannot be avoided, the Magnet Effect parameter should be programmed to None. 

Laser procedures – Turn the ReActiv8 IPG Mode to OFF. Keep the laser directed away from all components of ReActiv8. 

Electromagnetic interference (EMI) from household items 

Most household appliances and equipment that are working properly and grounded properly will not interfere with the ReActiv8 System. Many household items contain magnets or generate magnetic fields that are strong enough to activate the magnet switch inside the IPG, which can be programmed to start or stop therapy. 

If interference is suspected, instruct the patient to move away or turn off the household item.

The Mainstay Tunneler (Model TUN1) contains up to 0.26% cobalt, which exceeds the hazardous substance limit of 0.1% w/w. 

The implantation of ReActiv8 involves risks similar to those of peripheral nerve stimulators. In addition to risks commonly associated with surgery, implantation or use of ReActiv8 includes, but is not limited to, the following risks:

Target Population

ReActiv8 is not suitable for every patient with chronic low back pain. When selecting candidates for ReActiv8, consider the following:

The safety and effectiveness of the ReActiv8 system has not been established for:

Manufacturer’s name and address

Mainstay Medical Limited

Clonmel House,
Forster Way,
Swords, Co. Dublin, K67F2K3