Relationship between Clinical Outcomes and Spontaneous Canal Remodeling in Thoracolumbar Burst Fracture

Objectives To analyze the relationship between clinical factors and spontaneous canal remodeling. Methods We evaluated computed tomography scans, before surgery, within a week after surgery, 6 months after surgery, and 12 months after surgery. Thirty-eight consecutive patients who underwent posterior fixation and fusion after thoracolumbar burst fractures were included in. Factors potentially affecting the postoperative degree of reduction and spontaneous spinal remodeling were defined as age, location, degree of change of anterior vertebral compression ratio, fracture type of the retropulse bone, presence of injury to the posterior longitudinal ligament, and posterolateral complex fracture. Multiple regression analyses were conducted on these factors to analyze the extent of their influence on the reduction and resorption rates. Results The recovery rate of the anterior compression (P = 0.003) was significantly related to the reduction rate after surgery; in addition, the recovery rate of the anterior compression (P = 0.022) and the comminuted type of fracture (P = 0.019) were significantly associated with the resorption rate after surgery. Conclusions During posterior fixation, the degree of the reduction of the vertebral body by distraction can affect the degree of postoperative reduction and spontaneous bone remodeling. Therefore, close attention must be given to the indirect reduction technique through distraction during the operation. Because comminuted fracture fragments affect spontaneous canal remodeling, the degree of postoperative resorption can be estimated by preoperative computed tomography imaging.