Outcomes of surgical intervention for degenerative lumbar spondylolisthesis: a comparative analysis of different surgical fixation techniques

BACKGROUND: Debate regarding effectiveness of surgical modalities contributes to a lack of consensus of decision making for surgical interventions. Furthermore, data regarding cost effectiveness, surgical operative time, resources, patient hospital stay and recovery is limited, particularly in the medium term for degenerative lumbar spondylolisthesis. The objective was to compare clinical outcomes following different fixation interventions treating degenerative lumbar spondylolisthesis. METHODS: A retrospective cohort study using the British Spine Registry (BSR) of 1,838 patients aged ≥18 years. Five hundred and five patients undergoing posterior lumbar interbody fusion (PLIF) and 1,333 undergoing transforaminal lumbar interbody fusion (TLIF) with 6 months follow-up, were compared. Demographics, Oswestry Disability Index (ODI), Numerical Rating Scale (NRS) [back and leg], quality of life, complications and cost effectiveness were analysed. RESULTS: NRS (back and leg) demonstrated a statistically significant difference favouring TLIF at 6 months (P=0.04) and (P<0.05) respectively. There was no difference in ODI improvement at 6 months between PLIF and TLIF (P=0.620), but there was a statistically significant difference in ODI scores preoperatively between PLIF and TLIF (P<0.001). EQ-5D-5L–Health VAS (P=0.136) and EQ-5D-5L (P=0.655) did not show a statistically significant difference in improvement between PLIF and TLIF. Dural tear was the most common complication and was higher in the PLIF group (5.7%) but not statistically significant. Estimated blood loss was greater for PLIF (P=0.041). Implant cost (P<0.001) was higher for TLIF whereas theatre time was higher for PLIF (P=0.031). CONCLUSIONS: Both PLIF and TLIF result in clinically significant improvements in ODI, NRS back pain and NRS leg pain, with superiority of TLIF for improvements in back and leg pain. Surgeons appeared to use ODI preoperatively to decide intervention with comparable improvements for both approaches. Average theatre time and blood loss volume was higher for PLIF. Factors like implant costs and costs of consumables were higher for TLIF. Costs merit further evaluation.