Intervertebral Vacuum Phenomenon After Thoracolumbar Burst Fractures Undergoing Minimally Invasive Posterior Internal Fixation: Assessing Risk Factors in a Pilot Study.

Abstract

To investigate the fracture-associated vacuum phenomenon (FAVP) occurring after thoracolumbar burst fractures and its risk factors and association with lower back pain. A retrospective analysis of patients with thoracolumbar burst fractures (T10 to L5) was conducted from January 2018 to December 2021 at the Lishui Central Hospital. The primary outcome was new-onset FAVP after fracture, with patients classified into the FAVP and non-FAVP groups. Data collected included fracture details, patient demographics, lifestyle factors, and clinical information. Binary logistic regression assessed factors linked to FAVP development. VAS and ODI scores were recorded at 36 months post-fracture. 134 patients (mean age, 51 years ± 10, 82 men) were evaluated, of these, 47% emerged the FAVP at an average interval of 10 ± 7 months after fracture. Of the 77 discs that developed FAVP, 91% were adjacent to the fractured endplate, and more frequently occurs in the upper disc of fractured vertebrae. Associated factors were disc injuries (P < 0.001), diabetes(P < 0.05), Type A3/A4 fracture of anterior column (P = 0.002/P = 0.05), male gender (P = 0.03), and PLC injury (P = 0.05). The FAVP group showed worse improvement in VAS and ODI scores at the final follow-up (P < 0.05). The FAVP was commonly observed in the upper intervertebral discs adjacent to fractured endplates. Factors such as disc injuries, diabetes, Type A3/A4 fractures of the anterior column, male gender, and PLC injuries were associated with increased odds of FAVP. The presence of FAVP was associated with less favorable outcomes in terms of pain.