Timing of Surgery and Predictors of Canal Reduction after Short- segment Fixation for Thoracolumbar Burst Fractures

Purpose In patients with thoracolumbar burst fractures, surgical delay is often unavoidable due to concomitant injuries. Concerns persist that delayed surgery may compromise indirect reduction of retropulsed fragments via ligamentotaxis. This study aimed to determine whether the timing of surgery affects the quality of intracanal fragment reduction and identify independent predictors of successful reduction following short-segment posterior fixation. Methods This multicenter study included 252 patients who sustained a single traumatic thoracolumbar burst fracture and underwent short-segment fixation. The canal compromise ratio (CCR) was measured on pre- and postoperative CT scans, and the reduction rate was calculated using this formula: Reduction rate = (Preoperative CCR − Postoperative CCR) / Preoperative CCR × 100. Multiple logistic regression analysis identified predictors of reduction quality including age, sex, affected level, surgical timing, AO classification, load-sharing score (LSS), preoperative CCR, and concomitant vertebroplasty, Results The study included 141 males and 111 females. The mean time from injury to surgery was 3.8 days. The mean CCR improved from 45% to 24%, yielding a mean reduction rate of 44%. Multiple linear regression analysis revealed that T11 to L1 and AO type B fractures were associated with a significantly higher reduction rate. Notably, the time from injury to surgery showed no significant correlation with reduction quality. Conclusion Short-segment posterior fixation can achieve satisfactory canal reduction through ligamentotaxis, even when surgical intervention is delayed several days after trauma. In polytrauma patients without neurological deficit, a short postponement of surgery may be acceptable to optimize systemic stabilization without compromising spinal canal restoration.