Table 2. The data of clinical outcomes from baseline to two years follow-up.

Clinical parameters	L4–5 TLIF (N=191)	L4–5 & L5–S1 TLIF (N=18)
VAS of low back pain
Baseline	6.3±1.8	6.4±2.3
3 months after operation	1.7±1.0*	1.9±1.2*
24 months after operation	1.5±1.0*	1.7±1.4*
VAS of leg pain
Baseline	6.9±1.4	6.8±1.4
3 months after operation	1.9±1.2*	1.8±1.1*
24 months after operation	1.7±1.0*	1.6±1.0*
ODI
Baseline	63.2±11.5	61.1±8.5
3 months after operation	31.1±5.9*	32.6±6.8*
24 months after operation	29.8±7.5*	29.3±6.0*

*, P<0.05 compare to baseline data. TLIF, transforaminal lumbar interbody fusion; VAS, visual analog scale; ODI, Oswestry Disability Index.