IE-LRD — Interlaminar Endoscopic Lateral Recess Decompression

Within the spinal canal, before a nerve reaches its own exit foramen, it passes through the lateral recess — a shallow corner bounded by the facet joint behind, the vertebral body in front, and the pedicle to the side. Degenerative change here, chiefly an overgrown superior facet and thickened ligament, can narrow this corner and trap the travelling nerve root just as it turns down. This produces leg pain, often with a clear nerve pattern, and it is a distinct problem from central stenosis, though the two frequently coexist.

The interlaminar endoscopic lateral recess decompression targets exactly that corner. Working through the interlaminar window from behind, under continuous irrigation and magnified vision, the ligamentum flavum is opened and the overgrown medial part of the superior facet — the bone crowding the recess — is carefully trimmed with a fine burr and punches until the travelling nerve is freed and has room to move. The nerve is followed along its course into the recess to confirm it is decompressed all the way to its exit. Because the approach is a targeted keyhole rather than a wide opening, the facet joint is only partly trimmed, the muscles are spared, and the segment's stability is preserved. Decompression is confirmed when the nerve lies free and the dural sac pulses normally.

The skill lies in removing precisely the bone that is trapping the nerve — the medial edge of the superior facet — while leaving enough of the joint and the pars intact to keep the segment stable, and in working confidently right beside the nerve and its covering through a small window. Judging the extent of decompression, and recognising when lateral recess stenosis sits alongside central or foraminal narrowing that also needs addressing in the same sitting, is exactly the kind of targeted, anatomy-led decision-making that endoscopic subspecialisation is built on.

The evidence here is particularly strong. The landmark randomised controlled trial by Ruetten and colleagues compared full-endoscopic interlaminar decompression with conventional microsurgery for lumbar lateral recess stenosis and found equivalent clinical results with less trauma, less pain and faster rehabilitation from the endoscopic approach — one of the highest-quality pieces of evidence in the field. Subsequent case series and outcome studies report excellent improvements in disability and leg pain, with high proportions of good and excellent results, and confirm that the targeted endoscopic approach decompresses the recess reliably while preserving the facet and the muscles. This robust evidence base is a large part of why I favour the endoscopic route for this problem.

Because the operation is a targeted keyhole that spares the muscles and most of the joint, recovery is usually quick — many people go home the same day or the next, walking, with early relief of the leg pain. Some temporary nerve sensitivity can occur in the first weeks and usually settles; numbness and long-standing weakness may take longer to recover and do not always resolve fully. Activity is built back up over the following weeks, and the spine is followed up over the longer term.

• —Ruetten S, et al. Full-endoscopic interlaminar versus conventional microsurgical decompression for lateral recess stenosis (RCT). (PMID 19929343)
• —Interlaminar endoscopic lateral recess decompression: surgical technique and early clinical results. (PMID 28744491 / PMC5506307)
• —Surgical outcomes of full-endoscopic interlaminar lateral recess decompression. (PMID 39993943 / PMC11962290)
• —Full-endoscopic interlaminar approach for lateral recess stenosis: technique and outcomes. (PMID 36912548)
• —Endoscopic interlaminar standalone decompression for lateral recess stenosis with subligamentous disc herniation. (PMID 40448447 / PMC12214423)
• —Uniportal endoscopic interlaminar decompression in lumbar stenosis: comprehensive review. (PMC9421280)