Incidence and Associated Factors for Kyphosis Progression in Short-Segment Fixation Thoracolumbar Spine Fractures

Int J Spine Surg. 2022 Aug;16(5):815-820. doi: 10.14444/8343. Epub 2022 Aug 31.


Background: The thoracolumbar spine is the most frequently affected portion of the spine during fractures. In surgical management, short-segment fixation is the treatment of choice because of preserved spine motion and fewer complications. However, this technique causes concerns of kyphosis progression compared with long-segment fixation. The widely used load-sharing classification was of limited value for predicting kyphosis progression in recent literature. The goal of this study was to identify the incidence and explore the factors associated with kyphosis progression in short-segment fixation in thoracolumbar spine fractures.

Study design: Retrospective cohort study.

Methods: Patients with thoracolumbar spine fractures and no known neurological deficits treated by short-segment fixation and followed up for at least 12 months during January 2015 to October 2019 were included in this study. Demographic and radiographic data parameters were collected from the hospital database. Incidence of kyphosis progression was collected, and multivariable logistic regression analysis was used to explore associated factors.

Results: A total of 91 patients were included in this study. The most common fractures were AO-type A3 in 57.7% of patients, followed by A4 in 31.9%, A2 in 9.9%, and B in 6.6%. Posterior ligamentous complex (PLC) injuries were found in 51.7%. The incidence of kyphosis progression was 35.2%. The PLC was found to be significantly associated with kyphosis progression (OR 3.14, P = 0.040). Intermediate screw insertion was a preventive factor (OR 0.11, P = 0.043). Age, body mass index, and type of fracture were not significant associated factors.

Conclusion: The incidence of kyphosis progression was 35.2%. The PLC injury and intermediate screw insertion were significant associated factors. Long-segment fixation in a patient who had PLC injury or intermediate screw insertion should be considered to prevent kyphosis progression.

Clinical relevance: PLC injury was significantly associated with kyphosis progression in short segment thoracolumbar fracture fixation. Therefore, the surgeon should carefully select treatment options for these groups of patients.

Keywords: kyphosis; pedicle screws; spinal fracture; thoracolumbar spine.