Table 1. Description of the involvement side and Kellgreen & Lawrence classification according to groups and result of the statistical tests.

	Group
Variable	1x6mL		3x2mL		Total		p
	N	%	N	%	N	%
Side							0.710*
Right	4	7.5	3	5.8	7	6.7
Left	5	9.4	3	5.8	8	7.6
Bilateral	44	83.0	46	88.5	90	85.7
Total	53	100	52	100	105	100
Kellgreen & Lawrence's radiological classification of the R knee							0.503**
I	5	9.4	6	12.0	11	10.7
II	22	41.5	24	48.0	46	44.7
III	20	37.7	13	26.0	33	32.0
IV	6	11.3	7	14.0	13	12.6
Total	53	100	50	100	103	100
Kellgreen & Lawrence's radiological classification of the L knee							0.487**
I	6	11.5	3	5.8	9	8.7
II	22	42.3	30	57.7	52	50.0
III	15	28.8	14	26.9	29	27.9
IV	9	17.3	5	9.6	14	13.5
Total	52	100	52	100	104	100

^* Result of the likelihood ratio test

^** Result of the Mann-Whitney test