The objective of this study was to assess the usability and safety of
BION injectable neuromuscular microstimulators for
therapeutic electrical stimulation (
TES) to treat two conditions involving
disuse atrophy: poststroke shoulder subluxation in hemiplegic subjects and
knee osteoarthritis. Clinicians were provided with PC-based software to track implants and to design the exercise programs. Subjects self-administered
TES (3 sessions/day, 10-30 min/session) for 6 or 12 weeks. Outcome measures included subluxation for the shoulder study and knee function and
pain for the
osteoarthritis study. All subjects were comfortable with the
BION equipment and
therapy; eight of 10 experimental subjects elected to continue treatment after the study period. Shoulder subluxation was reduced by 55% ± 54%; knee function was enhanced by 65% ± 24%; and knee
pain decreased by 78% ± 18%. The devices did not migrate and did not cause
inflammation or
pain. Thresholds were stable over time. We conclude that the use of
BION implants to exercise atrophic muscles was well-accepted and provided effective rehabilitation in these two clinical conditions.