Does Minimally Invasive Lumbar Spine Fusion Reduce Adjacent Segment Degeneration? A Matched-Pair Analysis With 8-Year Follow-up

Objective: This study aimed to compare the long-term radiographic incidence of adjacent segment degeneration (ASD) following minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) versus open TLIF (O-TLIF) in a matched cohort, and to identify radiographic parameters associated with the development of kyphosis-type ASD.Methods: A retrospective matched-pair analysis was conducted involving 60 patients (30 MIS-TLIF and 30 O-TLIF) who underwent single-level TLIF between 2004 and 2009 and had a minimum follow-up of 8 years. Patients were matched for age (±3 years), sex, body mass index (±2 kg/m²), and operative level. Radiographic ASD was defined as greater than 50% disc-height loss, greater than 3 mm of listhesis, or greater than 10° of kyphotic change at the adjacent segment. Continuous variables were analyzed using independent-sample t-tests or Mann-Whitney U-tests, as appropriate, and categorical variables were analyzed using chi-square or Fisher exact tests, with statistical significance set at p