The use of classification and regression tree analysis to identify the optimal surgical timing for improving neurological outcomes following motor-complete thoracolumbar traumatic spinal cord injury

Study design Observational cohort study. Objectives To identify the optimal surgical timing for improving neurological outcomes in patients that sustained a motor-complete traumatic spinal cord injury (TSCI) secondary to a thoracolumbar injury. Setting Level 1 trauma center specialized in TSCI care. Methods We prospectively analyzed clinical data of 35 patients admitted for motor-complete TSCI secondary to a thoracolumbar injury. We quantified neurological recovery with three different outcomes: the improvement of at least one grade on the American Spinal Injury Association Impairment Scale (AIS), of at least one neurological level of injury (NLI), and of at least 10-points on the motor score (MS). Classification and regression tree analysis was used to identify outcome predictors and to provide cutoff values of surgical timing associated with recovery. Results The proportion of the patients improving by at least one AIS grade was higher in the group undergoing early surgery within 25.7 h of the TSCI (46% vs 0%). The proportion of patients that improved by at least one NLI was also higher in the group undergoing early surgery within 21.5 h of the TSCI (71% vs 18%). Lastly, 25% of the AIS grade A patients undergoing early surgery within 25.6 h of the TSCI improved 10 MS points or more as compared with 0% in the other group. Conclusions Earlier surgery was effective in improving neurological outcome in motor-complete TSCI at the thoracolumbar levels. Performing surgery within 21.5 h from the traumatic event in these patients increases the likelihood of improving the neurological recovery. Sponsorship This study was supported by the Fonds de Recherche du Québec—Santé (FRQS), Department of the Army—United States Army Medical Research Acquisition Activity, Rick Hansen Spinal Cord Injury Registry and Medtronic research chair in spinal trauma at Université de Montréal.