Contribution of the xenograft bone plate-screw system in lumbar transpedicular stabilization: An in vivo study in dogs

OBJECTIVES Xenograft bone plate-screws (XBPSs) can be alternative tools in lumbar transpedicular stabilization (TS). The aim of this study was to show biomechanical and histopathological contribution of the XBPSs system in lumbar TS. MATERIALS AND METHODS Fifteen (n = 15) hybrid dog and ten (n = 10) L2-4 cadaveric specimens were included in the study. The dogs were separated according to surgical techniques: L3 laminectomy and bilateral facetectomy (LBF) in Group I (experimental group [EG I] (n = 5), L3 LBF plus TS with metal plate-screws (MPSs) in Group II (EG II) (n = 5), and L3 LBF plus TS with XBPSs in Group III (EG III) (n = 5). The cadaveric specimens were separated to L2-4 intact in Group I (CG I), (n = 5), and L3 LBF in Group II (CG II), (n = 5). The dogs were sacrificed at the end of 3rd month, and their L2-4 spinal segments were en bloc removed and prepared as in control groups. Flexion, extension, left-right bending, rotation, and compression tests were applied to all segments. Stiffness values were calculated and analyzed statistically. All dog segments were evaluated histopathologically. RESULTS XBPS system showed a higher average stiffness values for left bending, extension, flexion, and compression compared to MPS, but these differences were not statistically meaningful. XBPS system had superiority to the fusion formation, as well. CONCLUSIONS XBPSs provide stability and help the fusion formation, but this system does not have a biomechanical advantage over MPS system in TS.