STUDY DESIGN: A biomechanical investigation using indentation tests in human cadaveric lumbar vertebrae. OBJECTIVES: To determine the effect of endplate removal on the structural properties across the lower lumbar vertebral bodies (L3-L5). SUMMARY OF BACKGROUND DATA: The structural properties of the vertebral endplates exhibit substantial regional variation. In addition, several recent studies of the endplate-implant interface have suggested that the endplate is not a significant structural element. METHODS: The bony endplates on the left or right side of seven intact human vertebrae (L3-L5) were removed with a high-speed burr. Indentation tests were performed at standardized test sites on both sides of the endplate using a 3-mm diameter, hemispherical indenter with a test rate of 0.2 mm/s to a depth of 3 mm. The failure load and stiffness at each site were determined from the load-displacement curves. Three-way repeated measures analyses of variance were used to analyze the resulting data for variation in the anterior-posterior and lateral directions, as well as to determine the effect of endplate removal. RESULTS: For the intact endplates, both the failure load and stiffness varied significantly across the endplate surfaces (P