Table 2.

Differences in Z-scores between SOS and BMD, taken in pairs

	n=95	SOS-R SOS-L	SOS-R LS-BMD	SOS-L LS-BMD	P
GP	Advanced n= 20	0.03 ± 0.74 −1.6 to 1.0	0.99 ± 1.37 −0.3 to 4.7	0.95 ± 1.39 −0.6 to 3.8	NS
	Normal n= 36	0.18 ± 1.07a −2.3 to 2.9b	0.22 ± 1.4 −2.5 to 3.6	−0.05 ± 1.26 −2.1 to 3.0	NS
	Delayed n= 39	0.19 ± 1.09 −1.7 to 2.5	−0.82 ± 1.7 −5.2 to 2.4	−1.02 ± 1.89 −4.0 to 2.7	0.03
	P	NS	0.001	0.001
TW	Advanced n= 19	−0.09 ± 0.68 −1.6 to 0.8	0.35 ± 0.8 −1.0 to 2.0	0.45 ± 1.33 −1.8 to 2.9	NS
	Normal n= 36	0.07 ± 0.91 −2.3 to 1.7	0.23 ± 1.95 −4.6 to 4.7	0.28 ± 1.64 −3.7 to 3.8	NS
	Delayed n= 40	0.32 ± 1.18 −1.7 to 2.9	−0.59 ± 1.55 −5.2 to 1.9	−0.95 ± 1.75 −4.0 to 2.7	0.001
	P	NS	NS	0.004
	Total	0.19 ± 1.02 −2.3 to 2.9	−0.07 ± 1.67 −5.2 to 4.7	0.25 ± 1.73 −4.0 to 3.8	NS

Age and gender matched standard deviations scores, (Z), of ultrasound-speed of sound (SOS)- m/sec, of the right (R) and left (L) radii, and bone mineral density (BMD)-g/cm², of the lumbar spine (LS, L2-4).

Bone age interpreted from the left hand and wrist radiographs with the Greulich and Pyle (GP) and Tanner and Whitehouse (TW) methods. Normal, delayed and advanced bone ages were based on the measurements by author BM: normal bone age (< ± 1 year from the chronological age), delayed bone age (≤ −1 year) and advanced bone age (≥ +1 year)

^aMean of difference between measurements ± standard deviation/years

^bRange of differences/years

P- value (one way analysis of variance)