Comparative Evaluation of Pre- and Postoperative Oswestry Disability Index in Lumbar Canal Stenosis, Instability, and Listhesis Following TLIF

Background: Lumbar degenerative pathologies such as canal stenosis, segmental instability, and listhesis are common causes of chronic back pain and disability. Transforaminal Lumbar Interbody Fusion (TLIF) is a wellestablished surgical intervention for these conditions, offering decompression, stabilization, and alignment restoration. Functional assessment using the Oswestry Disability Index (ODI) is essential to gauge patient-reported outcomes. Objective: This study aimed to compare preoperative and postoperative ODI scores among patients with lumbar canal stenosis (LCS), LCS with instability, and listhesis undergoing TLIF using local corticocancellous bone grafts. Methods: A retro-prospective observational study was conducted on 100 patients undergoing TLIF at a tertiary center. Based on preoperative diagnosis, patients were categorized into three groups: LCS (n=44), LCS with instability (n=33), and listhesis (n=23). ODI scores were recorded preoperatively, on postoperative day 1, at 3 months, and at 1 year. Statistical analysis was performed using paired t-tests and ANOVA. A p-value < 0.05 was considered significant. Results: Baseline ODI was highest in the LCS group (61.13 ± 5.81), followed by LCS with instability (60.09 ± 4.66), and listhesis (58.17 ± 4.77), though the difference was not statistically significant (p=0.0921). Postoperative ODI scores showed marked improvement across all groups. Day 1 scores were similar among groups (p=0.9092), while significant differences emerged at 3 months (p<0.0001) and 1 year (p<0.0001). Intragroup analysis revealed substantial reduction in ODI from baseline to 1 year (LCS: ↓52.04, Instability: ↓51.88, Listhesis: ↓50.56; p<0.0001). Conclusion: TLIF using corticocancellous bone grafts leads to significant and sustained reduction in disability across lumbar degenerative pathologies. Despite variation in baseline disability, all diagnostic groups experienced comparable postoperative functional gains, reinforcing TLIF's role as a versatile and effective surgical modality.