Endoscopic electrode implantation for enhanced stimulation of the hamstring branches of the sciatic nerve in paralyzed subjects.

Seven hamstring branches of the sciatic nerves in eight posterior thighs of four paraplegics were implanted with electrodes endoscopically. Strong initial responses were obtained in each case on continuous electrical stimulation. Three of the implants were removed immediately due to rapid decay in the response to stimulation; two had muscle power reduced to grade IV and two to grade III over 2-week period postoperatively. We believe the reduction in strength was partly due to hematoma surrounding the electrode and partly due to migration of the electrode away from the target nerves. Further work needs to be done to improve the technique and implant designs to improve results. Due to the excellent visual control it offers, this technique has the potential for accurate implantation of electrodes without massive exposures and its attendant morbidity.