CLINICAL USE OF PERCUTANEOUS INTRAMUSCULAR ELECTRODES FOR FUNCTIONAL ELECTRICAL-STIMULATION

Objective: To evaluate the clinical use of the percutaneous intramuscu lar electrode in functional electrical stimulation Design: Randomized and controlled study. Setting: A referral center and institutional pra ctice providing outpatient care. Patients: Seventeen patients (12 men, 5 women) who had implanted percutaneous intramuscular electrodes for more than 1 year were examined. The average follow-up time after impla ntation of electrodes was 2.2 years (range, 1yr to 4yr 10mo). Overall, there were 327 electrodes (83 upper extremities and 234 lower extremi ties). Intervention: The indwelling electrode was composed of helicall y coiled Teflon-coated rope stranded from 19 hard drawn wires of SUS 3 16L stainless steel (SES 114). Main Outcome Measures: The rates of bre akage, movement, and infection. and the number of electrodes that need ed reimplantation were evaluated. Results: Only one electrode broke (0 .3%) in the iliopsoas muscle at 12 weeks after implantation. Eight ele ctrodes (2.4%) were removed because of loss of sufficient contraction force caused by movement of the electrodes. Movements occurred at 9 we eks in 6 electrodes and at 5 months in two. The failure rate of electr odes in the lower extremities was 3.7%. No failures occurred in the up per extremities, Ten electrodes (3.1%) required reimplantation. Althou gh ten superficial infections (3.1%) were seen around the site of elec trode insertion, no removals of electrode were needed. All electrodes in one patient were removed, however, because of generalized methicill in-resistant Staphylococcus aurcus infection complicated with renal di sease. Electrodes were reimplanted after improvement of the infectio. Conclusions: The ultrafine percutaneous intramuscular electrode was co nsidered practical for long-term FES use. (C) 1996 by the American Con gress of Rehabilitation Medicine and tile American Academy of Physical Medicine and Rehabilitation