Surgical technique for installing an eight-channel neuroprosthesis for standing

Area of Science:

• Biomedical Engineering
• Neurosurgery
• Rehabilitation Medicine

Background:

• Spinal cord injury often results in impaired lower extremity function, limiting mobility and independence.
• Functional neuromuscular stimulation (FNS) offers a potential solution for restoring movement.
• Standardized surgical procedures are crucial for the widespread adoption of implanted neuroprostheses.

Purpose of the Study:

• To develop and standardize a surgical procedure for implanting an eight-channel FNS system in the lower extremities.
• To identify target muscles, surgical approaches, and procedural stages for optimal neuroprosthesis implantation.
• To assess the effectiveness and stability of the implanted system for functional activities.

Main Methods:

• Development of a standardized surgical procedure for implanting an eight-channel receiver-stimulator and associated electrodes.
• Identification of target muscles (vastus lateralis, gluteus maximus, semimembranosus, erector spinae) and corresponding surgical approaches via cadaveric studies and intraoperative testing.
• Three-stage implantation procedure performed in a single surgical session, with electrode placement guided by bony landmarks.

Main Results:

• Successful implantation of the FNS system in seven individuals with spinal cord injury.
• Achieved strong, isolated stimulated muscle contractions enabling body elevation, standing support with a walker, and pivot transfers.
• Demonstrated the effectiveness and stability of the implanted neuroprosthesis for functional mobility.

Conclusions:

• A standardized, repeatable, and teachable surgical procedure for lower extremity FNS implantation has been established.
• The developed FNS system effectively restores key functional movements in individuals with spinal cord injury.
• This standardized procedure will facilitate multicenter clinical trials for broader application and validation.