Figure 2.

Transverse section of proximal tibia. The original plug protruded 0.1 mm deeper than the piston (the black line). The lowest position for the piston is 0.6 mm from the bone surface (the middle dotted line). The highest position is 1.4 mm from the bone surface, (the upper dotted line). Thus, a total volume of 8.6 mm³ under the piston, reduced to 4.5 mm³ when the piston is moved to the lower position during a pressure cycle.