Comparison of Clinical Characteristics and the Relationship with Adjacent Segment Degeneration in LDD Patients with Different BMI after TLIF

Purpose To investigate the changes in clinical characteristics after TLIF in LDD patients with different Body Mass Index (BMI) and to analyze the relationship between BMI and the occurrence of ASD. Methods Patients who were diagnosed with L4-5 or L5-S1 single-level LDD and underwent TLIF at Chifeng Municipal Hospital from January 2021 to January 2023 were consecutively enrolled. Patients were divided into a high BMI group (BMI ≥ 25 kg/m²) and a control group (BMI < 25 kg/m²) based on their BMI at admission. The patients were followed up for 2 years. The differences in clinical characteristics and the incidence of ASD after operation were compared between the two groups, and the relationship between BMI and other indices was analyzed. Results A total of 122 patients completed the study, with 65 in the high BMI group and 57 in the control group. Compared with the control group, the high BMI group had a higher incidence of ASD at 2 years after TLIF (P < 0.05). The VAS score for low back pain was higher in the high BMI group (P < 0.05). The ODI score was higher (P < 0.05). ROM at the adjacent level was higher (P < 0.05). Multivariate logistic regression analysis showed that BMI ≥ 25 kg/m2 (P < 0.05) was a risk factor for ASD after TLIF in LDD patients. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic value of BMI for ASD after TLIF in LDD patients [0.745 (95% confidence interval: 0.616–0.876), P < 0.05]. Conclusion Compared with patients with normal BMI, patients with high BMI have a higher incidence of ASD after TLIF, more obvious low back pain, and worse postoperative functional recovery. BMI ≥ 25 kg/m2 is a risk factor for postoperative ASD in patients with LDD, and BMI has a certain predictive value for ASD.