Percutaneous implantation of iliopsoas for functional neuromuscular stimulation.

Hip flexion is required for walking and stair climbing. Percutaneous electrical stimulation of the iliopsoas muscle is a potentially useful and reliable method of providing hip flexion in individuals who are paralyzed. In this study, groin, lateral abdominal, and paraspinal approaches of percutaneous electrode implantation for electrical stimulation of the iliopsoas muscle are described. The paraspinal approach using stimulation of the second and third lumbar roots gave the best hip flexion response; however, it often was accompanied by unwanted stimulation of the hip adductor and abdominal muscles. Wire breakage and electrode movement were the most common causes for failure of maintaining hip flexion. The paraspinal approach, using double helix electrodes, provided an average of 110 weeks of functional hip flexion sufficient for walking. It is feasible to implant electrodes in the iliopsoas muscle. An open technique for permanent implantation of intramuscular electrodes is being developed to selectively stimulate the iliopsoas, which will extend the range and duration of hip flexion that will allow stair climbing in individuals who are paraplegic.