(a)
(b)
(c)
(d)
Figure 2: Finite-element model of ELIF and TLIF under different internal fixation modes. (a) ELIF + UPS. (b) TLIF + UPS. (c) ELIF + UPS + TLFS. (d) TLIF + BPS. ELIF: extraforaminal lumbar interbody fusion; TLIF: transforaminal lumbar interbody fusion; UPS: unilateral pedicle screw fixation; BPS: bilateral pedicle screw fixation; TLFS: translaminar facet screw.