Lumbar Microdiscectomy

When a lumbar disc herniates, a fragment of the soft inner disc pushes out through a tear in its tough outer ring and presses on a nerve root as it leaves the spine. That pressure and the inflammation around it produce sciatica — pain, pins and needles, numbness or weakness running down the leg in the territory of the nerve. Most disc herniations settle with time and non-operative care. When they do not, or when there is significant or progressive weakness, surgery is offered. The operation removes the offending fragment and frees the nerve. A traditional microdiscectomy does this through a small incision under the microscope, retracting the muscle off the bone; my preferred approach does the same through an endoscope, with even less disturbance to the tissues.

My reasoning is the same as for any decompression. The operation is defined by what happens at the nerve — clearing the fragment that is compressing it and making sure the nerve is free. It is not defined by the size of the wound. The endoscopic approach lets me reach the disc through a tiny portal under continuous magnified irrigation, removing the fragment while sparing the muscles and ligaments almost entirely. The result at the nerve is the same, but the insult to the body is smaller: less muscle injury, less bleeding, less post-operative pain, and often a faster, more comfortable return to normal life. For a problem where the whole aim is to relieve the leg with as little collateral damage as possible, the endoscopic route fits that aim beautifully, which is why it is my default.

There are two full-endoscopic corridors to a lumbar disc, and I choose between them according to the level and the position of the fragment. The transforaminal route reaches the disc from the side, through the natural window where the nerve exits, and is often ideal because it avoids the back of the spine altogether. The interlaminar route reaches the disc from behind, through the small gap between the laminae, and is particularly useful at the lowest level of the spine. In addition, the biportal endoscopic technique — using two tiny portals, one for the camera and one for the instruments — offers a familiar, well-illuminated view with a little more room to work. All of these share the same goal and the same low-insult philosophy; the art is matching the corridor to the individual's anatomy.

Honesty matters here. I said I seldom operate open, and there are genuine exceptions. Certain migrated fragments, very large central herniations causing severe compression, difficult anatomy, or a fragment sitting in a position that the endoscopic corridors cannot safely reach may be better and more safely dealt with through an open microdiscectomy. Open microdiscectomy remains an excellent, reliable operation, and I am entirely comfortable performing it when it is the right choice. The point is simply that, for the majority of straightforward disc herniations, the endoscopic route achieves the same relief with less disturbance to the body — and where it does not fit, I choose the approach that is safest for that person.

No honest account of disc surgery is complete without mentioning recurrence. Whatever the technique, once a disc has herniated and a fragment has been removed, there remains a defect in the outer ring, and in a minority of people a further fragment can herniate through it at some point in the future — a recurrent disc herniation. This happens in a small but real percentage of cases and is not a reflection of the operation being done poorly; it is a feature of the disc itself. Certain factors, such as smoking, a large defect in the disc wall and diabetes, raise the risk. I discuss this openly, because managing expectations honestly is part of good care, and recurrence, if it happens, has its own well-established treatments.

The evidence is strong and supports both the operation and the endoscopic route. The landmark SPORT trial showed that discectomy gives faster and greater relief of sciatica than continued non-operative care, with benefits maintained at long-term follow-up. On technique, a landmark randomised trial by Ruetten and colleagues and a large multicentre randomised trial published in the BMJ both found full-endoscopic discectomy to be at least as effective as open microdiscectomy for relieving sciatica, with less tissue trauma and quicker recovery; multiple meta-analyses reach the same conclusion, and biportal endoscopic discectomy performs comparably. Direct measures of muscle injury — blood markers and imaging of the muscles — confirm less damage with the minimally invasive routes. In the interest of balance, it is worth saying that a well-conducted trial of tubular minimally invasive discectomy did not show a clear clinical advantage over conventional microdiscectomy at one year, which tells us that the long-term relief of the leg is broadly similar whichever careful technique is used. That is honest, and it is exactly why I frame the endoscopic advantage as one of a gentler approach and recovery rather than a better nerve result. There is a real learning curve to these techniques.

Relief of the leg pain is often immediate or very early, which is one of the most gratifying things about this operation. Because the tissues are spared, most people go home the same day or the next with a small dressing, walking, and build activity back up over the following days and weeks. Numbness and long-standing weakness can take longer to recover and occasionally do not fully resolve. Care is taken early on to avoid heavy lifting and repeated bending while the disc settles, and physiotherapy supports a graded return to full activity. The spine is followed up over the longer term.

• —Weinstein JN, et al. Surgical versus nonoperative treatment for lumbar disc herniation: eight-year SPORT results. (PMID 24153171 / PMC3921966)
• —Ruetten S, et al. Full-endoscopic versus conventional microsurgical discectomy (RCT). (PMID 18427312)
• —Gadjradj PS, et al. Full-endoscopic versus open discectomy for sciatica (PTED): multicentre RCT. (PMID 35190388 / PMC8859734)
• —Gadjradj PS, et al. Full-endoscopic transforaminal versus open microdiscectomy for sciatica: systematic review. (PMID 35867477)
• —PTED versus open lumbar discectomy: systematic review and meta-analysis. (PMID 36439526 / PMC9691761)
• —Percutaneous endoscopy versus traditional open surgery for disc herniation: meta-analysis. (PMID 35340255)
• —Percutaneous endoscopic lumbar discectomy versus open microdiscectomy: meta-analysis. (PMID 30205219)
• —Muthu S, et al. Unilateral biportal endoscopic discectomy versus microdiscectomy: systematic review and meta-analysis. (PMID 38388729)
• —Single-level biportal endoscopic versus tubular microdiscectomy: outcomes and opioid use. (PMID 39304409)
• —Arts MP, et al. Tubular diskectomy versus conventional microdiskectomy for sciatica (SIPS RCT). (PMID 19584344)
• —Arts M, et al. Does minimally invasive lumbar disc surgery cause less muscle injury? (RCT). (PMID 20556439)
• —Serum CPK as an indicator of muscle injury: full-endoscopic versus microdiscectomy. (PMID 27101087)
• —Akmal S, et al. Risk factors for recurrent lumbar disc herniation: systematic review and meta-analysis. (PMID 26765413 / PMC4718239)
• —Long-term reoperation rates after single-level lumbar discectomy: nationwide cohort. (PMID 40085443)