Biportal Endoscopic Lumbar Fusion

Most people with back and leg pain never need a fusion, and I only recommend it when a segment is genuinely unstable — such as a degenerative slip — or when thoroughly freeing a trapped nerve would leave the level unstable. The question is then how to fuse with the least collateral damage. The biportal approach is attractive because the two-portal set-up separates seeing from working: the endoscope in one portal gives a continuously irrigated, high-magnification view of the nerves and disc space, while the second portal allows the use of ordinary, strong instruments with a full range of movement. This makes the decompression and disc preparation efficient and thorough, while still sparing much of the muscle that a traditional open fusion would strip away.

Two small incisions are made on one side of the spine. Through them, under continuous saline irrigation, I introduce the endoscope and the working instruments, decompress the trapped nerve, remove the worn disc and prepare the endplates, and then insert an interbody cage packed with bone graft to restore height, open the nerve channels and provide a scaffold for fusion. The construct is typically supported with percutaneous pedicle screws placed through small incisions. Because the technique uses conventional instruments under clear endoscopic vision, it combines a thorough, controlled decompression and disc clearance with the muscle-sparing advantages of a minimally invasive approach.

The biportal endoscopic approach to lumbar fusion has been studied increasingly, including in systematic reviews and meta-analyses that compare it directly with minimally invasive and open transforaminal interbody fusion. These analyses report comparable fusion and clinical outcomes with, in several studies, advantages in early recovery, blood loss and tissue trauma, while also acknowledging a learning curve and the usual risks of any fusion. Technical descriptions set out how the operation is performed and refined. The balanced view is that biportal endoscopic fusion is an effective, well-tolerated, minimally invasive option for well-selected patients, delivering the goals of a traditional fusion with less muscle disruption when performed by an experienced endoscopic surgeon.

Biportal endoscopic lumbar fusion is carried out under anaesthetic, and because the muscle disruption is much less than an open fusion, the hospital stay is often short and early mobilisation is encouraged. The cage and screws give immediate stability while the fusion consolidates over the following months, supported by a graded return to activity and rehabilitation. As with any fusion there are risks, and the technique is demanding and has a learning curve, so careful selection matters; all of this is discussed fully beforehand, and whether a biportal endoscopic fusion — as opposed to another technique — is right for you is decided together.

• —Yang H, et al. Unilateral biportal endoscopic lumbar interbody fusion enhanced recovery compared with conventional posterior procedures: a systematic review and meta-analysis. Front Neurol 2022. (PMID 36703632)
• —Yu Q, et al. Unilateral biportal endoscopic transforaminal lumbar interbody fusion versus conventional interbody fusion for degenerative lumbar spine disease: a systematic review and meta-analysis. BMC Musculoskelet Disord 2023. (PMID 37875873)
• —Luan H, et al. Comparing unilateral biportal endoscopic TLIF and MIS-TLIF in lumbar degenerative diseases: a systematic review and meta-analysis. J Orthop Surg Res 2023. (PMID 37993948)
• —Wang Q, et al. Unilateral biportal endoscopic fusion versus minimally invasive fusion for lumbar degenerative diseases: a systematic review and meta-analysis. Eur Spine J 2023. (PMID 36867251)
• —Kim JE, et al. Biportal endoscopic transforaminal lumbar interbody fusion with arthroscopy. Clin Orthop Surg 2018. (PMID 29854350)
• —Kang MS, et al. Biportal endoscopic technique for transforaminal lumbar interbody fusion: review of current research. Int J Spine Surg 2021. (PMID 35027471)