Table 2.

VAS (back and leg pain), ODI and SF-36 test results

Test	Preoperative	6 months	12 months	24 months
VAS back
Unilateral	7.8 ± 0.8	2.3 ± 0.9	2.1 ± 1.8	2.1 ± 0.8
Bilateral	8.1 ± 0.7	2.3 ± 0.7	2.4 ± 2.6	2.0 ± 1.8
VAS leg
Unilateral	7.4 ± 2.8	2.1 ± 1.7	2.2 ± 1.1	1.9 ± 1.4
Bilateral	7.1 ± 1.3	2.2 ± 0.9	2.0 ± 1.5	2.0 ± 1.3
ODI
Unilateral	42.4 ± 16	20.6 ± 15.1	18.6 ± 5.7	18.8 ± 3.2
Bilateral	44.3 ± 18.2	21.8 ± 16.4	19.8 ± 8.3	17.9 ± 7.6
SF-36
PF
Unilateral	16.7 ± 6.2	–	45.6 ± 9.0	47.2 ± 15.2
Bilateral	15.8 ± 2.5	–	44.1 ± 11.0	46.1 ± 12.7
GH
Unilateral	49.6 ± 13.4	–	58.4 ± 10.4	57.8 ± 16.5
Bilateral	51.8 ± 8.3	–	57.6 ± 11.0	58 ± 13.3
MH
Unilateral	51.3 ± 16.2	–	69.1 ± 15.5	71.5 ± 18
Bilateral	50.4 ± 11.8	–	69.9 ± 17.4	72.6 ± 21.2

PF physical function, GH general health, MH mental health

Data presented as mean±SD. Difference significant (P < 0.01) pre- and postoperatively in both groups. Difference not significant between outcomes at 12- and 24-months follow-up for each subscale