Increased paraspinal muscles fatty infiltration and ligamentum flavum hypertrophy as independent predictors of posterior revision surgery following lateral lumbar interbody fusion with lateral plate fixation: a retrospective study.

Abstract

Retrospective study. To assess the revision rate of lateral lumbar interbody fusion (LLIF) with lateral plate fixation (LLIF+LP) and to evaluate the preoperative radiological parameters associated with the need for revision. LLIF is a minimally invasive option that provides indirect decompression and favorable fusion rates; however, stand-alone LLIF has been associated with substantial early revision rates. The addition of lateral plate fixation (LLIF+LP) enhances segmental stability, yet the predictors of revision following LLIF+LP remain poorly defined. Patients who underwent LLIF+LP were categorized into two groups: non-revision and revision. Central canal stenosis, lateral recess stenosis, foraminal stenosis, facet joint degeneration, endplate Modic changes, ligamentum flavum hypertrophy (>4 mm), and fat infiltration (FI) grade of the lumbar multifidus muscle were evaluated. Clinical efficacy was determined using the Visual Analog Scale (VAS), Oswestry Disability Index (ODI), and Japanese Orthopaedic Association (JOA) scores, assessed both preoperatively and at the final follow-up. A total of 163 patients were included in the study, consisting of 144 in the non-revision group and 19 in the revision group, yielding an overall revision rate of 11.7% (19/163). Univariate and multivariate logistic regression analyses demonstrated that ligamentum flavum hypertrophy and the FI grade of the lumbar multifidus muscle were significantly associated with the revision rate (p<0.05). No significant differences were observed between the revision and non-revision groups in preoperative or postoperative patient-reported outcomes for VAS back pain, VAS leg pain, ODI, and JOA scores (p>0.05). LLIF+LP surgery yields favorable outcomes for lumbar degenerative diseases with a low reoperation rate. Preoperative evaluation of ligamentum flavum hypertrophy and the FI grade of the lumbar multifidus muscle may assist in guiding surgical planning, preoperative discussions, and management of patient expectations.