Biportal Endoscopic Fusion

A lumbar interbody fusion removes a worn or unstable disc and replaces it with a cage that restores height and holds the vertebrae until they fuse into one. In a biportal endoscopic fusion, this is done through two small portals rather than an open incision: one carries the endoscope, giving a magnified, continuously irrigated view of the disc space and the nerves, while the other carries the instruments used to decompress the nerves, clear the disc and place the cage. Percutaneous screws and rods are added through separate stab incisions to hold the segment while it fuses. The two-portal set-up gives the surgeon a degree of freedom and a field of view that many find close to open surgery, delivered with the tissue preservation of an endoscopic approach.

The appeal of the biportal technique is that it combines much of the visibility and instrument freedom of open surgery with the muscle-sparing, low-insult benefits of endoscopy — the same low-demand, low-insult principle I apply across my practice. Separating the camera from the instruments means the tools can be angled independently, which makes decompressing the nerves and preparing the disc for fusion more straightforward than through a single channel. I use it, like full-endoscopic fusion, for selected lower-demand problems — a single unstable or degenerate segment causing nerve compression — where the aim is a solid, well-aligned fusion achieved with as little muscle disruption as possible. Which endoscopic fusion technique suits a given patient is a judgement I make case by case.

Biportal fusion still asks a great deal of the surgeon: coordinating two portals, maintaining a clear irrigated field, decompressing the nerves safely and placing the cage accurately to restore height and alignment. There is a genuine learning curve, and success depends on careful case selection and refined technique. Having both the uniportal full-endoscopic and the biportal techniques at my disposal, and knowing which fits a given segment and patient, is exactly the kind of subspecialty flexibility that I have built my endoscopic practice around.

The evidence for biportal endoscopic fusion is robust and growing. Multiple systematic reviews and meta-analyses comparing biportal endoscopic TLIF with minimally invasive open TLIF find comparable fusion rates and clinical outcomes, with the biportal approach showing less blood loss, less postoperative drainage, shorter hospital stays and faster early functional recovery. Comparisons with uniportal endoscopic fusion show broadly similar results, and a large network meta-analysis of minimally invasive, full-endoscopic and biportal fusion supports equivalent fusion and outcomes across the techniques with reduced surgical insult. Studies applying enhanced-recovery pathways to biportal fusion report particularly quick early recovery. This is the evidence base I rely on in offering it selectively.

Because the muscles are largely spared, recovery from a biportal endoscopic fusion is often quicker than from a traditional fusion, with less early pain and blood loss — many people are up and moving soon afterwards and home within a few days. There is still a period of weeks to months during which the bone is knitting and heavy activity is limited, with physiotherapy supporting a graded return. The fused level is now stiff because it is joined, while the rest of the spine continues to move. The spine is followed up over the longer term to confirm the fusion is solid.

• —Luan H, et al. Biportal endoscopic versus MIS-TLIF for lumbar degenerative disease: systematic review and meta-analysis. (PMID 37993948 / PMC10664638)
• —Yu, et al. Biportal endoscopic TLIF versus conventional interbody fusion: systematic review and meta-analysis. (PMID 37875873 / PMC10594799)
• —Ding, et al. Biportal versus uniportal endoscopic TLIF: systematic review and meta-analysis. (PMID 39702176 / PMC11660777)
• —Lin GX, et al. Biportal endoscopic interbody fusion versus conventional fusion: systematic review and meta-analysis. (PMID 35085805)
• —Kim JE, et al. MIS-TLIF versus biportal endoscopic TLIF for single-level lumbar disease. (PMID 33633061 / PMC8035997)
• —Heo DH, et al. Technique of biportal endoscopic transforaminal lumbar interbody fusion. (PMID 32746526)
• —Comparative efficacy of minimally invasive, full-endoscopic and biportal TLIF: network meta-analysis. (PMID 41420307)