Abstract
This meta-analysis aims to determine the clinical outcomes, complications, and fusion rates in endoscopic assisted intra-foraminal lumbar interbody fusion (iLIF) and minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) for lumbar degenerative diseases. The MEDLINE, Embase, and Cochrane Library databases were searched. The inclusion criteria were: five or more consecutive patients who underwent iLIF or MI-TLIF for lumbar degenerative diseases; description of the surgical technique; clinical outcome measures, complications and imaging assessment; minimum follow-up of 12 months. Surgical time, blood loss, and length of hospital stay were extracted. Mean outcome improvements were pooled and compared with minimal clinically important differences (MCID). Pooled and direct meta-analysis were evaluated. We identified 42 eligible studies. The iLIF group had significantly lower mean intra-operative blood loss, unstandardized mean difference (UMD) 110.61 mL (95%CI 70.43; 150.80; p value < 0.0001), and significantly decreased length of hospital stay (UMD 2.36; 95%CI 1.77; 2.94; p value < 0.0001). Visual analogue scale (VAS) back, VAS leg and Oswestry disability index (ODI) baseline to last follow-up mean improvements were statistically significant (p value < 0.0001), and clinically important for both groups (MCID VAS back > 1.16; MCID VAS leg > 1.36; MCID > 12.40). There was no significant difference in complication nor fusion rates between both cohorts. Interbody fusion using either iLIF or MI-TLIF leads to significant and clinically important improvements in clinical outcomes for lumbar degenerative diseases. Both procedures provide high rates of fusion at 12 months or later, without significant difference in complication rates. iLIF is associated with significantly less intraoperative blood loss and length of hospital stay. Study registration: PROSPERO international prospective register of systematic reviews: Registration No. CRD42020180980, accessible at https://www.crd.york.ac.uk/prospero/ April 2020.