In Vivo Quantitative Ultrasound Image Analysis of Femoral Subchondral Bone in Knee Osteoarthritis

Table 2

Spearman’s rank correlations (𝑟) between ultrasound femoral (FB) bone depth level intensities and intensity slope and radiographic K-L grading or femoral arthroscopic scoring 1 (FAS1).

	K-L grading			FAS1
	𝑛	𝑟	95% CI	𝑛	𝑟	95% CI
FB level 1	31	0.491**	0.165–0.720	39	0.139	−0.185–0.435
FB level 2	31	0.600***	0.312–0.787	39	0.332*	0.018–0.586
FB level 3	31	0.310	−0.050–0.598	39	0.195	−0.128–0.481
FB level 4	31	0.378*	0.027–0.646	39	−0.016	−0.330–0.301
FB level 5	31	0.238	−0.127–0.547	39	0.053	−0.267–0.362
FB level all	31	0.464**	0.131–0.703	39	0.161	−0.163–0.453
FB slope	31	0.486**	0.159–0.717	39	0.335*	0.022–0.588

^∗𝑃<0.05.
^∗∗𝑃<0.01.
^∗∗∗𝑃<0.001.