RESUMEN
INTRODUCTION: The intermediate screw in a fractured vertebra works as a pressure point with an anterior vector thus creating a lordotic force that corrects kyphosis, provides appropriate three-point fixation and decreases the lever effect. OBJECTIVE: To describe the course of non-pathologic traumatic fractures of the thoracolumbar spine after instrumentation of the fractured vertebra. MATERIAL AND METHODS: A total of 37 patients with a diagnosis of traumatic vertebral fracture in the thoracolumbar area (T9-L4) were operated from January 2008 to December 2012. Patients included 28 males (75.6%) and 9 females (24.4%); mean age was 41.8 years. RESULTS: Correcting the total diameter of the spinal canal results in a 2.11 times higher chance of neurologic improvement; the relative risk of fusion was 0.97 with autologous graft as compared with a heterologous graft (CI 95% = 0.69-1.36) and 1.18 with instrumentation of the fractured vertebra (CI 95% = 0.42-3.31). CONCLUSIONS: Pedicle screw fixation at the fracture level is a safe and effective method to treat thoracolumbar fractures; it provides additional fixation points that assist in fracture reduction and correction of kyphosis, improving at the same time back pain and maintaining the corrective effect. Procedure indications include integrity of the posterior ligament complex and at least one intact pedicle in the fractured vertebra.