Twenty-one patients with burst fracture of the thoracolumbar spine were treated by posterior pedicle screw instrumentation and fusion. We assessed canal compromise using CT fcan preoperatively and its restoration shortly after instrunientation lot confirmation of effect of lisamentotafis. The amount of neurologic recovery in each patient was compared to the final area of the spinal canal. The mean initial canal compromise was 42.6% and this was reduced to 16.2% postoperatively. The mean sagittal diameter was 10.2mm preoperatively & 12.9mm postoperatively. We achieved a mean reduction of canal compromise of 62%. A significant correlation between preoperative canal compromise and amount of restoration, or severity of neurologic deficit could not be established. Ligamentotaxis by pedicle screw instrumentation could effectively decompress the canal in thoracolumbar burst fracture.