Publication:

Low-grade spondylolisthesis: is transforaminal lumbar interbody fusion superior to posterolateral fusion

Background Spondylolisthesis is anterior translation of the cephalad vertebra relative to the adjacent caudal segment. Both posterolateral fusion (PLF) and transforaminal lumbar interbody fusion (TLIF) and have shown high fusion rates with good clinical outcomes. But it is not clear which treatment leads to better outcomes, as limited studies have been done to compare PLF and TLIF in low grade spondylolisthesis. Our objective is to determine whether PLF or TLIF was associated with better clinical and radiological outcomes in patients with low grade spondylolisthesis.

Methods Fourty patients were enrolled and assigned into PLF (n=20) or TLIF (n=20) group. The outcome measures were: clinical outcomes as assessed with a visual analogue scale and the modified Oswestry disability index, the fusion rate based on radiographs.

Results The improvement of visual analog score (VAS) of low back pain was greater in TLIF than in PLF (89.6% versus 88.7%, p=0.79). The improvement of VAS of leg pain was greater in TLIF than in PLF (96.5% versus 94.8%; p=0.27). The improvement of Oswestry disability index (ODI) was greater in TLIF than in PLF (71.7% vs 69.8%, p=0.32). The fusion rate was 85% in TLIF and 75% in PLF (p=0.43).  Overall outcome was excellent in 80% in TLIF compared to 65% in PLF (p=0.29).

Conclusions Fusion rates are higher in TLIF and average functional outcomes (VAS and ODI) were better in TLIF compared to PLF.  Larger and longer studies may provide a significant outcome. Based on our results and literature review, we conclude that TLIF is superior to PLF.