Risk factor analysis for predicting kyphosis reoccurrence of thoracolumbar burst fracture patients treated with posterior short-segment fixation

Abstract

Background: The thresholds of risk factors of kyphosis recurrence in thoracolumbar burst fracture patients were still controversial. The aim of this multi-center study was to identify these thresholds. Methods: 169 patients were included in this study. Upper intervertebral angle (UIVA), lower intervertebral angle (LIVA), Cobb angle (CA), anterior vertebral height ratio (AVH%), regional angle (RA), posterior vertebral height ratio (PVH%), vertebral wedge angle (VWA), anteroposterior ratio (A/P%), Clinical assessment included Load Sharing Classification (LSC) score, Thoracolumbar Injury Classification and Severity (TLICS) score, Visual Analogue Scale (VAS), and Body mass index (BMI) were perioperatively evaluated. Patients were divided into KR group and none KR (NKR) group according to whether the loss of CA correction was less than 5˚ or not. The risk factors of KR before or after implant removal were analyzed, respectively. Results: There were significant improvements in postoperative parameters compared with preoperative parameters, such as AVH%, A/P%, VAS, CA, VWA, PVH% ( P < 0.001, respectively), and UIVA ( P = 0.02). Age (AUC = 0.828) and BMI (AUC = 0.846) were good predictors of KR before implant removal. BMI (AUC = 0.871) was a good predictor of KR after implant removal. Conclusions: There were significant differences in risk factors of KR at different postoperative follow-up stages: age > 49 years, BMI > 24 were risk factors of KR before implant removal; BMI > 25.17 was a risk factor of KR after implant removal.