title: Longitudinal performance of a surgically implanted neuroprosthesis for lower-extremity exercise, standing, and transfers after spinal cord injury.
abstract: OBJECTIVE
  To investigate the longitudinal performance of a surgically implanted neuroprosthesis for lower-extremity exercise, standing, and transfers after spinal cord injury.
  
  
  METHODS
  Case series.
  
  
  METHODS
  Research or outpatient physical therapy departments of 4 academic hospitals.
  
  
  METHODS
  Subjects (N=15) with thoracic or low cervical level spinal cord injuries who had received the 8-channel neuroprosthesis for exercise and standing.
  
  
  METHODS
  After completing rehabilitation with the device, the subjects were discharged to unrestricted home use of the system. A series of assessments were performed before discharge and at a follow-up appointment approximately 1 year later.
  
  
  METHODS
  Neuroprosthesis usage, maximum standing time, body weight support, knee strength, knee fatigue index, electrode stability, and component survivability.
  
  
  RESULTS
  Levels of maximum standing time, body weight support, knee strength, and knee fatigue index were not statistically different from discharge to follow-up (P>.05). Additionally, neuroprosthesis usage was consistent with subjects choosing to use the system on approximately half of the days during each monitoring period. Although the number of hours using the neuroprosthesis remained constant, subjects shifted their usage to more functional standing versus more maintenance exercise, suggesting that the subjects incorporated the neuroprosthesis into their lives. Safety and reliability of the system were demonstrated by electrode stability and a high component survivability rate (>90%).
  
  
  CONCLUSIONS
  This group of 15 subjects is the largest cohort of implanted lower-extremity neuroprosthetic exercise and standing system users. The safety and efficiency data from this group, and acceptance of the neuroprosthesis as demonstrated by continued usage, indicate that future efforts toward commercialization of a similar device may be warranted.
authors.affiliation: Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH 44106, USA.
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Triolo
authors.forename: Stephanie Nogan
authors.initials: SN
authors.lastname: Bailey
authors.forename: Michael E
authors.initials: ME
authors.lastname: Miller
authors.forename: Loretta M
authors.initials: LM
authors.lastname: Rohde
authors.forename: James S
authors.initials: JS
authors.lastname: Anderson
authors.forename: John A
authors.initials: JA
authors.lastname: Davis
authors.forename: James J
authors.initials: JJ
authors.lastname: Abbas
authors.forename: Lisa A
authors.initials: LA
authors.lastname: DiPonio
authors.forename: George P
authors.initials: GP
authors.lastname: Forrest
authors.forename: David R
authors.initials: DR
authors.lastname: Gater
authors.forename: Lynda J
authors.initials: LJ
authors.lastname: Yang
mesh_terms: D002574:Cervical Vertebrae; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D007717:Knee / Q000502:physiology*; D008137:Longitudinal Studies; D035002:Lower Extremity / Q000503:physiopathology; D008297:Male; D018763:Muscle Fatigue; D053580:Muscle Strength; D058117:Neural Prostheses / Q000009:adverse effects; D010342:Patient Acceptance of Health Care; D011475:Prosthesis Failure; D019919:Prosthesis Implantation; D013119:Spinal Cord Injuries / Q000503:physiopathology* / Q000534:rehabilitation / Q000601:surgery; D013904:Thoracic Vertebrae; D013997:Time Factors; D016474:Weight-Bearing / Q000502:physiology