Tibial speed of sound in term and preterm infants.

The tibial speed of sound (SOS) was measured in 91 healthy singleton infants between 31 and 42 weeks of gestation and 12 sick preterm infants. In healthy infants, the tibial SOS was associated with corrected gestational age (r = 0.40, p < 0.001) but not birth weight. The median tibial SOS in 12 sick preterm infants (2,772, range 2,566-2,934 m/s), whose corrected gestational age was between 31 and 42 weeks, was lower (p < 0.001) than that of 69 healthy gestation-matched healthy infants (3,100, range 2,870-3,381 m/s). Tibial SOS measurements may allow radiation-free assessment of metabolic bone disease of prematurity.