Augmenting Screw Technique to Prevent TLIF Cage Subsidence: A Biomechanical In Vitro Study

作者：Alina Jacob, Alicia Feist, Ivan Zderic, Boyko Gueorguiev, Jan Caspar, Christian Rainer Wirtz, R. Geoff Richards, Markus Loibl, Daniel Haschtmann, T. Fekete · 发表于：Bioengineering · 年份：2025 · DOI：10.3390/bioengineering12040337 · 被引用次数：3 · 研究领域：Spinal Fractures and Fixation Techniques、Spine and Intervertebral Disc Pathology、Bone fractures and treatments

(1) Cage subsidence in spine surgery is a frequent clinical challenge. This study aimed to assess a novel screw augmentation technique for Transforaminal Lumbar Interbody Fusion in cadavers of reduced bone mineral density (BMD). (2) Forty human lumbar vertebrae (BMD 84.2 ± 24.4 mgHA/cm3, range 51–119 mgHA/cm3) were assigned to two groups: augmenting screw group and control group. The augmentation technique comprised placement of two additional subcortical screws. Ten constructs per group were loaded with a quasi-static load-to-failure protocol and other ten were cyclically loaded. Failure modes were documented. (3) During the quasi-static load-to-failure testing, the augmenting screw technique showed a significantly higher failure load (1426.0 ± 863.6 N) versus the conventional technique in the control group (682.2 ± 174.5 N, p = 0.032). Cyclic loading revealed higher number of cycles and corresponding load until reaching 5 mm subsidence and significantly higher number of cycles and corresponding load until reaching 10 mm subsidence for the augmenting screw technique (9645 ± 3050; 1164.5 ± 305.0 N) versus the conventional technique in the control group (5395 ± 2340; 739.5 ± 234.0 N, p < 0.05). Failure modes were different and showed bending of the augmenting screws, followed by cut-out. (4) The investigated augmenting screw technique demonstrated higher failure loads and cycles to failure against cage subsidence compared to conventional cage placement. Failure modes were d...