Radiographic Analysis of Minimally Invasive Transforaminal Lumbar Interbody Fusion versus Conventional Open Surgery on Sagittal Lumbar-Pelvic Alignment for Degenerative Spondylolisthesis

To compare the impact of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) with open posterior lumbar interbody fusion (PLIF) on sagittal lumbar-pelvic radiographic parameters for degenerative spondylolisthesis (DS).Of 48 patients with L4 single segmental DS, 25 underwent MIS-TLIF with Quadrant system and 23 underwent conventional open PLIF. Comparisons of data from the preoperative and final follow-up standing lateral lumbar x-rays, with the bilateral femoral heads, of the 2 groups were conducted using the following parameters: slip percentage (SP), lumbar lordosis (LL), pelvic incidence, pelvic tilt (PT), sacral slope, lumbosacral angle, slip angle (SA), and the L1 axis and S1 distance (LASD).The slip reduction rate (ΔSP) in the OPEN group was significantly higher than in the MIS group (67 ± 34% vs. 37 ± 51%, P = 0.018). The change of SA (ΔSA) in the OPEN group was significantly higher than in the MIS group (3 ± 7° vs. -3 ± 5°, P = 0.003). The change of LASD (ΔLASD) in the OPEN group was significantly lower than in the MIS group (-4 ± 15 mm vs. 4 ± 9 mm, P = 0.033). There were positive correlations between the preoperative SP and LASD, and ΔSA and the change of LL (ΔLL), and a negative correlation between ΔLL and the change of PT (ΔPT).For low-grade DS, open PLIF has a higher rate of slip reduction compared to MIS-TLIF, and significantly reduces LASD, therefore, it is more conducive to improving lumbar sagittal balance.