Table 2. Comparison of general data.

Roussouly classification [n]	Gender, n			Segment, n				Direction of herniated disc, n				Pfirrmann classification, n				Epiphyseal separation, n
	Male	Female		L3/4	L4/5	L5/S1		Left	Right	Central		Level 3	Level 4	Level 5		With	Without
Type 1 [21]	14	7		1	2	18		12	8	1		2	15	4		5	16
Type 2 [56]	43	13		3	28	25		26	21	9		15	27	14		14	42
Type 3 [32]	21	11		0	27	5		17	13	2		5	16	11		10	22
Type 4 [4]	2	2		0	1	3		3	1	0		1	3	0		2	2
Type 3-AP [13]	8	5		0	5	8		6	6	1		2	5	6		4	9
χ2 value	2.826			32.623				4.796				9.429				1.615
P value	0.587			<0.001				0.779				0.307				0.806

For χ² test, P<0.05. Data have been adjusted using the Bonferroni method.