Surgical management of isthmic spondylolisthesis: A comparative study of postoperative outcomes between ALIF and TLIF

Circumferential fusion by the anterior (ALIF) or transforaminal (TLIF) approach combined with posterior instrumentation is currently used for the surgical treatment of low-grade isthmic spondylolisthesis. But few studies have compared the clinical and radiological outcomes of various interbody fusion techniques. The objective of this study was to compare the clinical and radiological results at 2 years postoperative of two fusion techniques-TLIF versus ALIF plus posterior instrumentation-for low-grade isthmic spondylolisthesis in adults.This was an observational multicenter study done at nine French healthcare facilities specialized in spine surgery. The inclusion criteria were minimum age of 18 years, grade 1-3 isthmic spondylolisthesis, ALIF+posterior fixation (ALIF+PS) or TLIF, minimum follow-up of 2 years. Clinical and radiological evaluations were done preoperatively and at 2 years of follow-up. A lumbar CT scan was done at 1 year postoperative to evaluate fusion.The cohort consisted of 89 patients (50 women, 39 men) with a mean age of 47.7±12.3 (18-79) years. The patients in the ALIF groups (n=71) had a significantly longer hospital stay than those in the TLIF group (n=18): 5.7 days versus 4.6 days (p=.04). However, their medical leave from work was significantly shorter: 31.0 weeks versus 40.7 (p=.003). Lumbar pain VAS diminished faster in the ALIF groups, with a significantly larger drop than the TLIF group in the first 3 months postoperative. Only the increase in lumbar disc lordosis was larger in the ALIF group: 11.7°±12.0° versus 6.0°±11.7° (p=.036). There was a significant correlation between the increase in global lordosis and reduction in lumbar VAS at 2 years postoperative (ρ=-0.3295; p=.021).ALIF+PS provides a faster relief of postoperative low back pain than TLIF but there are no significant clinical differences between techniques at 2 years of follow-up. Despite better restoration of disc lordosis in the ALIF+PS group, there was no difference in the restoration of global lordosis.III; multicenter comparative study.