[Table/Fig-3]:

Comparison of HA levels between Cases and Controls in different KL-Grades

KL-Grade	Cases (n=100)			Controls (n=50)			Significance of Difference
	No.	Mean	SD	No.	Mean	SD	"t"-test	"p" value
0	0	.	.	12	1.06	1.15	-	-
I	5	8.64	3.79	38	4.21	2.27	3.780	<0.001
II	39	14.77	7.08	–	–	–	–	–
III	43	38.28	41.34	–	–	–	–	–
IV	13	148.41	133.06	–	–	–	–	–
	F=20.39; p<0.001			F=3.64; p=0.063