Table 1.

Correlation of Ultrasound-SOS to LS-BMD

	r
		Bone Age-GP			Bone Age-TW
Measurement pairs	Total n= 95a	Advanced n= 20	Normal n= 36	Delayed n= 39	Advanced n= 18	Normal n= 36	Delayed n= 40
SOS-R(Z) SOS-L(Z)	0.78	0.86	0.71	0.81	0.91	0.83	0.72
SOS-R(Z) LS-BMD(Z)	0.08*	0.24*	0.16*	0.1*	0.65	0.34*+	0.14*
SOS-L(Z) LS-BMD(Z)	0.3*	0.39*	0.11*	0.06*	0.43*	0.03*	0.12*

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

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 blinded measurements by author BM: normal bone age (< ± 1 year from the chronological age), delayed bone age (≤ −1 year) and advanced bone age (≥ +1 year)

Correlation coefficient (r)

^a(n) number of individuals who had undergone a bone age measurement.

All the correlations were statistically significant to P=0.00, apart from those indicated by*

⁺Inverse relationship