Radiographic and Clinical Trade-Offs Between Expandable and Polyetheretherketone Cages in Endoscopic Transforaminal Lumbar Interbody Fusion
10.21182/jmisst.2025.02964
- Author:
Se-Heum PARK
1
;
Cheol Woong PARK
;
Cheng-Ying LEE
Author Information
1. Department of Neurosurgery, Daejeon Woori Hospital, Daejeon, Korea
- Publication Type:Original Article
- From:
Journal of Minimally Invasive Spine Surgery and Technique
2026;11(Suppl 1):S41-S52
- CountryRepublic of Korea
- Language:English
-
Abstract:
Objective:To compare 1-year radiographic and clinical outcomes between expandable cages and polyetheretherketone (PEEK) cages in patients undergoing endoscopic transforaminal lumbar interbody fusion (TLIF).
Methods:This retrospective, single-surgeon cohort study included 84 patients (32 expandable cage, 52 PEEK cage) with at least 1 year of radiographic and clinical follow-up. Radiographic parameters included disc height, foraminal height, segmental lordosis, subsidence, cage length, and the cage-to-vertebral body area ratio measured on computed tomography. Clinical outcomes were evaluated using Numerical Rating Scale (NRS) scores and Bridwell fusion grading. Group comparisons were performed using t-tests and chi-square tests, and multivariate regression analyses were conducted to identify independent predictors of subsidence and fusion.
Results:PEEK cages demonstrated greater correction of segmental lordosis (2.6° vs -0.3°, p=0.003) and significantly lower total subsidence (2.2±1.7 mm vs. 4.6±2.4 mm, p=0.001) compared with expandable cages. In contrast, expandable cages were associated with significantly greater improvement in back pain at 1 year (β=1.71 NRS points, p=0.014). A larger cage-to-vertebral body area ratio independently reduced the risk of severe subsidence ≥5 mm (odds ratio, 0.34 per 0.1 increase; p=0.033). Fusion outcomes, defined as Bridwell grades 1–2, did not differ significantly between the 2 groups.
Conclusion:Expandable cages provided greater back pain relief despite a higher degree of subsidence, whereas PEEK cages offered superior radiographic stability. These findings highlight important radiographic-clinical trade-offs in cage selection for endoscopic TLIF and support individualized decision-making based on patient anatomy, alignment objectives, and symptom profile.
