An experimental study was designed to investigate the development of compartment syndrome with the use of an intraosseous line in dogs. We used an open technique for insertion of a 20-gauge spinal needle to the tibia. The needle was secured to the tibia with bone cement. Throughout the intraosseous infusion of saline with radio-opaque dye (rate, 480 mL/h), serial radiographic examination and pressure monitoring of the anterolateral compartment of the leg was performed. Although there was no change up to approximately 350 mL of fluid infusion, the radio-opaque dye was detected in the soft tissues and compartment pressure increased to more than 35 mm Hg. Compartment pressure continued to increase in direct proportion to the amount of dye infused. In the present study, the possible technical errors, which may cause compartment syndrome. have been eliminated. However, compartment syndrome developed because of the failure of microvasculature within a muscle adjacent to bone. We suggest that there is a need for a dose- and time-dependent scala for safe intraosseous infusion. Copyright (C) 1996 by W.B. Saunders Company.