Analysis of Influencing Factors of Vertebral Height Loss After Pedicle Screw Fixation of Thoracolumbar Fracture

STUDY DESIGN: Retrospective case-control study. OBJECTIVE: To explore the related factors of vertebral height loss (VHL) after pedicle screw fixation of thoracolumbar fracture and to determine the optimum prediction point. SUMMARY OF BACKGROUND DATA: With the widespread application of thoracolumbar fracture internal fixation, VHL after the operation is increasingly presented. However, there is no unified conclusion on the specific cause of VHL and how to predict it. METHODS: A total of 186 patients were selected and divided into the loss group (n = 72) and the not-loss group (n = 114) according to whether the fractured vertebral height was lost after the operation. The two groups were compared concerning sex, age, body mass index, osteoporosis self-assessment tool for Asians (OSTA), fracture types, number of fractured vertebrae, preoperative Cobb angle and compression degree, number of screws, and extent of vertebral restore. Univariate analysis and Multivariate logistic regression analysis were performed to identify the independent factors for the VHL with the receiver operating characteristic curve and the optimal prediction value was calculated according to area under the curve. RESULTS: Multivariate logistic regression analysis showed that OSTA (P < 0.05) and preoperative vertebral compression (P < 0.05) were significantly correlated with postoperative VHL, which were independent risk factors for postoperative VHL. The OSTA of 2.32 and the preoperative vertebral compression degree of 38.5% were the best prediction points for postoperative VHL based on the Youden Index analysis. CONCLUSIONS: The OSTA and preoperative vertebral compression were independent risk factors for VHL. The risk of postoperative VHL was significantly higher when the OSTA was ≤2.32 or the preoperative vertebral compression was ≥38.5%. LEVEL OF EVIDENCE: Level III.