Thirty-four nonambulatory patients with progressive neuromuscular spinal deformity were surgically managed using a 1/4" U-shaped double rod construct with segmental instrumentation from T2 to the pelvis accompanied by posterior spinal fusion. Diagnoses included 17 patients with cerebral palsy, six with spina bifida, and 11 with other diseases (spinal muscular atrophy, Friedreich's ataxia, polyneuropathy, nemaline myopathy, and polio). Twenty-three patients had single uncompensated thoracolumbar curves, and 11 had a double curve pattern. The mean preoperative major curve was 66° (range, 22-132°), the secondary curve 58° (range, 23-84°). No postoperative spinal support was used. Mean curve correction was 36° or 54.6%. There were four major complications, including two implant failures requiring revision and two patients sustaining excessive intraoperative blood loss necessitating completion of the procedure in a second stage. There were two neurologic complications including one case of postoperative seizures and an L4 monoradicular neuropathy in a spina bifida patient. Four patients had temporary postoperative ileus, one gastroesophageal reflex, and four had urinary tract infections. There were no significant postoperative pulmonary complications. Excluding the patients with rod failure, mean loss of correction at mean follow-up of 21.3 months was 6.5%. The stability and curve correction obtained using this system supports its continued use in patients with progressive neuromuscular scoliosis.