Internal fixation of fractures of the thoracolumbar spine with early ambulation is evaluated in this study of 100 patients with 106 fractures, 34 of which were treated by recumbency, 13 with Meurig-Williams plates, and 59 with Harrington rods. Fracture reduction in the recumbent group was 14% unsatisfactory and 82% satisfactory; only one fracture was anatomically reduced. After plating, 38% of fracture reductions were unsatisfactory and 61 % were satisfactory. Harrington rod reduction and internal fixation resulted in 67% anatomic, 31 % satisfactory, and 2% unsatisfactory reductions. Neurologic improvement in partial lesions was 53% with Harrington rods and 44% with recumbent treatment. For paraplegic patients the time between treatment and wheelchair mobilization was reduced from 10.5 weeks with recumbent treatment to 5.3 weeks with Harrington instrumentation. Rehabilitation time for ambulatory candidates was decreased from 7.1 weeks to 2.5 weeks. Complications were reduced from 18% in the recumbent group to 7% in the Harrington rod group. By using the three above-three below, rod long/fuse short approach rather than the two above-two below with fusion over the length of the rods technique, the number of anatomic reductions was increased from 70% to 82% and the length of the fusion decreased from 4.8 levels to 1.4 levels.