Clinical Evaluation of Single Posterior Long-segment Fixation for Severe Thoracolumbar Fracture (AO type B)

Abstract

Background Acute thoracolumbar fracture is a common spine injury in clinical practice, and AO type B injury is a severe fracture based on the morphology of distraction. Controversy remains in approach selection and few studies focused on this type alone. We evaluated the radiologic and clinical results of 56 cases from our university hospital data bases, and aim to provide some ideas during the surgical planning for this patient cohort.Methods From January 2015 to December 2019, fifty-six patients with AO type B thoracolumbar fractures were treated in spine unit of this tertiary hospital. Patient demographics, surgical details, and follow-up data were reviewed. Clinical outcome were analyzed using the Oswestry Disability Index (ODI), Patient Health Questionnaire-9 (PHQ-9), and Visual Analogue Scale (VAS) system. Results All patients received a single posterior approach and an average of 5.7±2.6 segments was instrumented. 41 patients received consecutive, long-segment pedicle screw fixation, while 15 patients were treated by satellite rod due to pedicle fractures. Average preoperative focal kyphotic angle was 26.2±5.6 degrees, which improved significantly to 13.8±7.2 degrees after the procedure (p<0.05). Similar improvements were found in anterior vertebral height (AVH). At the final follow up, no significant loss of correction angle and AVH was detected compared to postoperation. Pain scores had improved over the postoperative months as well as ODI and PHQ-9 scores. No proximal junction kyphotic change was noted, and none of the patients had any implant failure at the final follow-up.Conclusion AO type B thoracolumbar fractures are severely unstable and associated with complicated injuries. Single posterior consecutive, long-segment instrumentation for AO type B thoracolumbar fracture achieved and maintained satisfactory outcome. For patients with broken pedicles at the fractured level, satellite rod enhancement may be a feasible choice of a supplementary procedure.