Intramedullary pressure in canine long bones.

Intramedullary pressure was measured bilaterally in 36 dogs: in the diaphysis and distal metaphysis of the femur, in the proximal metaphysis of the tibia and humerus, and in the diaphysis of the radius. Pressure measurements were repeated in 5 dogs, 14 days after the initial recordings. Mean (+/- SD) pressures in the femoral diaphysis and distal metaphysis were 27.6 (+/- 15.4) mm of Hg and 17.6 (+/- 10.5) mm of Hg, respectively. Mean (+/- SD) pressures in the tibial diaphysis and proximal metaphysis were 26.4 (+/- 13.0) mm of Hg and 17.9 (+/- 11.8) mm of Hg, respectively. Mean (+/- SD) pressures in the humeral diaphysis and proximal metaphysis were 26.2 (+/- 15.8) mm of Hg and 13.4 (+/- 7.7) mm of Hg, respectively. The mean (+/- SD) pressure in the radial diaphysis was 15.4 (+/- 18.9) mm of Hg. Metaphyseal pressure was significantly (P less than 0.05) lower than diaphyseal pressure. Repeated pressure measurements in 5 dogs did not vary significantly from initial values, suggesting that the wide range of pressure was real not artifactual.