Minimally-invasive lateral thoracic and lumbar interbody fusion (LLIF) with expandable interbody cages - Considerations, complications & outcomes

Introduction: Reports about lateral lumbar or thoracic interbody fusion (LLIF) using expandable interbody spacers are sparse. Research question: To report our experience with the use of expandable spacers for LLIF. Material and methods: We reviewed all consecutive LLIF patients with use of an expandable titanium interbody implant (ELSA (R) Expandable Integrated LLIF Spacer, Globus Medical Inc, PA (USA)) between September 2018 and January 2024. Results: We identified 503 patients, in which we performed LLIF at 732 levels. In 63 patients (12.5%) and 70 levels (9.6%) an expandable spacer was used. The mean age was 61.4 years, 57.1% were females. LLIF was performed between T11/12 - L4/5 in the setting of fusion procedures (mono-/bisegmental (20; 28.6%), 3-7 segments (29; 41.4%); >7 segments (21; 30.0%)), of which 21 (33.3%), 20 (31.8%) and 22 (34.9%) were for traumatic, deformity/revision and other diagnoses. Surgery included release of the anterior longitudinal ligament in 30 cases (42.9%). Intraoperative adverse events (AEs) were noted in 2 (3.2%), postoperative AEs in 27 (42.9%) at discharge, 17 (27.0%) at 3 months and 14 (22.2%) at 12 months. Segmental sagittal Cobb angle changed from 1.3 degrees (preoperative) to 13.0 degrees at discharge (p < 0.001), 12.7 degrees at 3 months (p < 0.001) and 13.3 degrees at 12 months (p < 0.001). Functional outcome was excellent/good in 43 (68.3%; 5 missing) at 3 months and in 37 (58.7%; 10 missing) at 12 months. Discussion and conclusion: The use of LLIF with an expandable spacer was safe, promoted solid fusion and enabled powerful correction of sagittal segmental Cobb angle, which was maintained during follow-up.