Midterm Clinical and Radiographic Outcomes of Transarticular Trephonic Plasty-Assisted Percutaneous Endoscopic Lumbar Interbody Fusion for Single-Level Lumbar Degenerative Disease: A Retrospective Cohort Study

Background/Objectives: To evaluate midterm clinical, radiographic, and safety outcomes after transarticular trephonic plasty (TTP)-assisted percutaneous endoscopic lumbar interbody fusion (PE-LIF) for lumbar degenerative disease. Methods: This retrospective single-center cohort included 130 patients with complete clinical and imaging assessments and at least 24 months of follow-up. Clinical outcomes included back and leg pain visual analog scales, Oswestry Disability Index (ODI), Japanese Orthopaedic Association score, 36-Item Short Form Health Survey (SF-36) component scores, and modified MacNab outcomes. Radiographic measurements and computed tomography-based Bridwell fusion grades were assessed. Linear mixed-effects models included categorical visits, a patient-specific random intercept, and adjustment for final follow-up duration; multiple comparisons used Holm correction. Results: Median follow-up was 42.5 months (interquartile range, 36.0–50.75; range, 29–60). Mean operative time was 133.45 ± 15.63 min. Estimated blood loss derived from preoperative-to-postoperative-day-1 hematocrit change was 323.76 ± 66.24 mL. The estimated final-versus-preoperative ODI change was −40.15 points (95% confidence interval, −41.02 to −39.29). Clinical scores and radiographic measurements differed from baseline at all postoperative visits (all adjusted p < 0.05). Pain scores decreased from the early assessment to 6 months; functional and quality-of-life scores changed through 12 months, with a further increase in the SF-36 physical component score at final follow-up. Bridwell grade I or II fusion occurred in 118 patients (90.8%), and 119 (91.5%) had excellent or good MacNab outcomes. Complications occurred in 10 patients (7.7%); 2 required reoperation (1.5%). Conclusions: The analyzed cohort had sustained clinical improvement after TTP-assisted PE-LIF, with fusion, complication, and reoperation rates of 90.8%, 7.7%, and 1.5%, respectively. Controlled studies are needed to determine the contribution of TTP to these outcomes.