AO Spine Clinical Practice Recommendations for Interbody Fusion at the Lumbo-Sacral Junction

Study DesignLiterature review with clinical recommendation.ObjectiveProvide a concise curation of recent literature in interbody fusions at the lumbo-sacral junction.MethodsLiterature is graded based on the integration of scientific methodology and expert opinion.ResultsArticle 1: ALIF with and without posterior instrumentation, Conditional recommendation: ALIF is comparable to 360 fusions in well selected patients. Article 2: ALIF+Perc Screws v. MIS TLIF at L5-S1, Conditional recommendation: use ALIF in cases where higher lordosis correction is needed, Article 3: L4-S1 ALIF v. TLIF with grade 1-2 osteotomy, Conditional recommendation: use ALIF in cases where higher lordosis correction is needed. Article 4: The Deformity TLIF, Conditional recommendation: additional corrective maneuvers (grade 2 osteotomy, rod compression, anterior placement of the cage in the disc, hinged motorized operative table) can aid in achieving lordosis correction. Article 5: Revision rates in isthmic spondylolisthesis, Conditional recommendation: interbody use and 360 fusions decrease revision rates. Article 6: ALIF v. TLIF for isthmic spondylolisthesis, Conditional recommendation: use ALIF+Perc screws when an anterior approach is feasible.ConclusionsSegmental alignment matters, even in short segment constructs. Patients who require large magnitude correction are likely better served with an anterior approach as the literature consistently shows greater lordosis change with ALIF compared to TLIF. Appropriate lordosis is possible with TLIF, but surgeons must implement additional technical steps. For anterior fusions, supplemental fixation reduces the nonunion risk, but may not be necessary in a narrow subset of stable listhesis with good bone quality.