Table 1.

General data of this study

	Group A (n)	Group B (n)	Group C (n)	P value (P A–B/P A–C/P B–C)
Number of patients	20	18	21
Male to female ratio	11:9	10:8	13:9
Age in years (range)	53.4 ± 5.2 (19–70)	48.5 ± 4.3 (30–65)	55.1 ± 6.3 (20–73)
Operation time (min)	170.5 ± 50.4	231.0 ± 30.2	190.4 ± 24.2	<0.05/>0.05/<0.05
Amount of bleeding (ml)	350.3 ± 99.3	448.3 ± 50.5	380.2 ± 44.5	<0.05/>0.05/<0.05
Hospitalization day (days)	8.2 ± 5.8	18.4 ± 8.7	12.4 ± 4.0	<0.05/<0.05/<0.05
Follow-up in months (range)	45.5 ± 6.1 (24–50)	42.6 ± 5.2 (26–60)	40 ± 3.8 (24–58)	>0.05/>0.05/>0.05
Mean fusion level (range)	3.8 (3–5)	4.8 (3–7)	4.0 (3–7)	<0.05/>0.05/<0.05

PA _– B, PA _– C, and PB _– C P value of comparison between groups A and B, A and C, B and C, by chi-square test, respectively