Spinal specimens are commonly sprayed with saline solution during mechanical testing to ensure adequate hydration. However, potting ofvertebrae inhibits physiological fluid exchange through the porous endplates during loading. This un-physiological flow regime may influencemechanical properties of intervertebral discs and therefore of the whole spinal unit.The objective of this study was to evaluate a new method of spinal specimen hydration through the vertebral body during in vitro testing inorder to improve consistency of mechanical behaviour. Ovine lumbar anterior column units were prepared for testing. Half of the specimenswere sprayed with Ringer’s solution and wrapped in plastic foil. The remainder received an additional saline infusion into the centre of eachvertebral body. Three consecutive compression steps were applied by a hydraulic testing machine. Average forces within four sectors of therelaxation curves were compared.Applying saline infusion improves the consistency of consecutive relaxation curves. Differences between consecutive relaxation curveswere less than those for standard hydration. The forces at the beginning of the relaxation curve were also lower for the infusion method.The standard deviation between specimens of each group was lower for saline infusion of vertebrae. Hence, the new method leads to moreconsistent in vitro testing conditions.