Biomechanical Effects of Facet Joint Violation after Single-level Lumbar Fusion with Transpedicular Screw and Rod Instrumentation
Document Type
Article
Abstract
STUDY DESIGN: In vitro biomechanical study. OBJECTIVE: This study aimed to investigate the biomechanical effects of facet joint violation (FV) on mobility and optically tracked intervertebral disc (IVD) surface strains at the upper level adjacent to L4-5 pedicle screw-rod fixation. SUMMARY OF BACKGROUND DATA: FV is a complication that can occur when placing lumbar pedicle screws; the reported incidence is as high as 50%. However, little is known about how FV affects superior adjacent-level spinal stability, and especially IVD strain, after lumbar fusion. METHODS: Fourteen cadaveric L3-S1 specimens underwent L4-5 pedicle-rod fixation, 7 in the facet joint preservation (FP) group and 7 in the FV group. Specimens were tested multidirectionally under pure moment loading (7.5 Nm). Colored maps of maximum (ε1) and minimum (ε2) principal surface strain changes on the lateral L3-4 disc were generated with the surface divided into 4 quarters anterior to posterior (Q1, Q2, Q3, and Q4, respectively) for subregional analyses. Range of motion (ROM) and IVD strain were normalized to intact upper adjacent-level and compared between the groups using analysis of variance. Statistical significance was set at P <0.05. RESULTS: Normalized ROM was significantly greater with FV versus FP in flexion (11% greater; P =0.04), right lateral bending (16% greater; P =0.03), and right axial rotation (23% greater; P =0.04). Normalized L3-4 IVD ε1 during right lateral bending was greater on average for the FV group than the FP group: Q1, 18% greater; Q2, 12% greater; Q3, 40% greater ( P <0.001); Q4, 9% greater. Normalized ε2 values during left axial rotation were greater in the FV group, the highest increase being 25% in Q3 ( P =0.02). CONCLUSIONS: Facet joint violation during single-level pedicle screw-rod fixation was associated with increased superior adjacent level mobility and alteration of disc surface strains, with significant increases in selected regions and directions of loading.
Publication Date
5-1-2023
Publication Title
Spine
E-ISSN
1528-1159
PubMed ID
37141463
Digital Object Identifier (DOI)
10.1097/BRS.0000000000004698
Recommended Citation
Wangsawatwong, Piyanat; de Andrada Pereira, Bernardo; Lehrman, Jennifer N.; Sawa, Anna G.; O'Neill, Luke K.; Turner, Jay D.; Uribe, Juan S.; and Kelly, Brian P., "Biomechanical Effects of Facet Joint Violation after Single-level Lumbar Fusion with Transpedicular Screw and Rod Instrumentation" (2023). Translational Neuroscience. 2240.
https://scholar.barrowneuro.org/neurobiology/2240