Objective To study the feasibility of fluoroscopically guided percutaneous internal fixation with the Universal Spine System(USS) in the treatment of thoracolumbar fractures.Methods A total of 8 patients with thoracolumbar fractures without the need of decompression of the spinal canal underwent posterior percutaneous pedicle screw fixation by using the USS from October 2002 to May 2004.A fixation rod was placed under the vertebrae muscle to complete the reduction and fixation.Results The operation time was 120~240 min(mean,140 min),and the intraoperative blood loss was 20~90 ml(mean,40 ml).The Cobb's angle decreased from 21.5??4.3? preoperatively to 2.7??1.5? postoperatively(t=17.541,P=0.001).The collapse of vertebra was 18.5%?4.1% preoperatively and 2.4%?1.0% postoperatively(t=16.504,P=0.001).All the patients got out of bed 3 weeks after operation with the assistance of girdle brace.Effects of treatment were evaluated according to the Frankel grade at the third postoperative week: 2 patients recovered from grade C to D,1 patient from D to E,1 patient remained in D, and 4 kept in E. Conclusions Percutaneous internal fixation by using the USS in the treatment of thoracolumbar fractures without the need of decompression of the spinal canal offers advantages of minimal invasion and quick recovery,though it has some technical difficulties and disadvantages of long-time exposure under X-ray.