Retrospective Case Control Study: Clinical and Computer Tomographic Fusion and Subsidence Evaluation for Single Level Uniportal Endoscopic Posterolateral Approach Transforaminal Lumbar Interbody Fusion Versus Microscopic Minimally Invasive Transforaminal Interbody Fusion

Study Design: Retrospective comparative study. Objective: Assessment of difference in clinical and computer tomographic outcomes between the 2 cohorts. Methods: Computer tomographic evaluation by Bridwell's grade, Kim's stage, Kim's subsidence grade and clinical evaluation by VAS, ODI and McNab's criteria on both cohorts. Results: 33 levels of Endo-TLIF and 22 levels of TLIF were included, with a mean follow up of 14.3 (10-24) and 22.9 (13-30) months respectively. Both Endo-TLIF and TLIF achieved significant improvement of pain and ODI at post-operative 4 week, 3 months and at final follow up with VAS 4.39 +/- 0.92, 5.27 +/- 1.16 and 5.73 +/- 1.21 in Endo-TLIF and 4.55 +/- 1.16, 5.05 +/- 1.1 I and 5.50 +/- 1.20 in TLIF respectively and ODI at post-operative 1 week, 3 months and final follow up were 43.15 +/- 6.57, 49.27 +/- 8.24 and 51.73 +/- 9.09 in Endo-TLIF and 41.73 +/- 7.98, 46.18 +/- 8.46 and 49.09 +/- 8.98 in TLIF respectively, P < 0.05. Compared to TLIF, Endo-TLIF achieved better VAS with 0.727 +/- 0.235 at 3 months and 0.727 +/- 0.252 at final follow up and better ODI with 3.88 +/- 1.50 at 3months and 3.42 +/- 1.63 at final follow up, P < 0.05. At 6 months radiological evaluation comparison of the EndoTLIF and TLIF showed significant with more favorable fusion rate in Endo-TLIF of -0.61 +/- 0.12 at 6 months and -0.49 +/- 0.12 at 1 year in Bridwell's grading and 0.70 +/- 0.15 at 6 months and 0.56 +/- 0.14 at 1 year in Kim's stage.There is less subsidence of 0.606 +/- 0.18 at 6 months and -0.561 +/- 0.20 at 1 year of Kim's subsidence grade, P < 0.05. Conclusion: Application of single level uniportal endoscopic posterolateral lumbar interbody fusion achieved better clinical outcomes and fusion rate with less subsidence than microscopic minimally invasive transforaminal lumbar interbody fusion in midterm evaluation for our cohorts of patients.