Impact of traumatic intervertebral disc injury on loss of correction following pedicle screw fixation for thoracolumbar fractures.

Background: Traumatic intervertebral disc injury, while frequently observed in thoracolumbar fractures, is often overlooked in clinical management. This research aimed to investigate how traumatic intervertebral disc injury influences spinal stability and to analyze the risk factors for correction loss after posterior pedicle screw fixation for thoracolumbar fractures.

Methods: A retrospective analysis was performed on 194 thoracolumbar fracture patients who received pedicle screw fixation. The assessment of disc injury was conducted using magnetic resonance imaging (MRI). Patients were categorized into intervertebral disc injury (IDI) and non-IDI (nIDI) groups. The clinical variables included visual analog scale (VAS) score, and American Spinal Injury Association score. The radiological data, comprising the vertebral wedge angle (VWA), Cobb angle (CA), disc angle, disc height, anterior (AVBHr), midline (MVBHr), and posterior vertebral body height ratio (PVBHr), were compared before surgery, one week after the operation, and at final follow-up. The mean follow-up duration was 12.7 ± 7.0 months.

Results: The mean VAS score showed significant improvement postoperatively. 22.6% of patients with IDI developed the intervertebral vacuum phenomenon. The IDI group exhibited significantly greater CA and VWA, as well as lower disc height, AVBHr and MVBHr than the non-IDI group at the last follow-up. Age (odds ratio [OR] = 1.038, 95% confidence interval [CI] = 1.011-1.066, P = 0.005), male (OR = 2.201, 95% CI = 1.107-4.377, P = 0.025), and IDI (OR = 2.463, 95% CI = 1.105-5.489, P = 0.028) were statistically significant risk factors for kyphosis correction loss according to multivariate logistic regression analysis.

Conclusion: Traumatic IDI contributes to loss of correction following thoracolumbar fractures and is closely associated with accelerated disc degeneration. Age, male, and IDI are independent risk factors for postoperative kyphosis recurrence in patients with thoracolumbar fractures.