Endoscopic Spine Surgery for Slipped Disc and Stenosis

Endoscopic spine surgery treats a slipped (herniated) disc or spinal stenosis through a small keyhole incision, using a camera and fine instruments passed through a narrow tube to free the compressed nerves. It is the last step of a ladder that starts with medicines, physiotherapy and a nerve block injection, and many patients walk and go home on the day of the operation.

Dr. Puneet Girdhar, then Principal Director & Head, Ortho Spine, MIS & Robotic Spine Surgery at BLK-Max Super Speciality Hospital, New Delhi, India, set out this pathway in his 2024 masterclass on spinal surgery technology. This article covers the conditions behind most spine operations, the decision to operate, the two keyhole routes, the other minimally invasive options and the recovery after fusion. It forms part of the spinal surgery technology guide.

The conditions behind most spine operations

Back pain is close to universal: almost everyone will have it at some point in life. Fewer than 1% of people with back pain need surgery, in Dr. Girdhar's estimate, and most are managed with medicines and physiotherapy. The common spine ailments he described fall into four groups.

Spinal stenosis is a narrowing of the spinal canal that compresses the nerves running through it. Its signature is walking intolerance: the patient cannot walk a long distance and has to sit down to relieve the symptoms. One of Dr. Girdhar's patients could not walk for more than five minutes without having to sit down, and had numbness in the legs.

Disc herniation, commonly called a slipped disc, occurs when part of the disc between two vertebrae bulges or ruptures and presses on a nerve. In the lower back it causes sciatica, a shooting pain down the leg; in the neck it causes pain radiating into the arm.

Disc collapse is the end stage of disc degeneration, in which the disc loses its height and the space between the vertebrae narrows.

Spondylolisthesis is the slip of one vertebra forward on the one below. In some patients it follows a fracture of the bony arch at the back of the vertebra, which allows the front of the spine to slide.

The treatment ladder: medicines, nerve block, surgery

Dr. Girdhar's approach to disc disease and stenosis follows three steps, which he repeated when asked in the session how discopathy (degenerative disc disease) should be managed:

1. Medicines and physiotherapy. The first line for every patient.
2. Nerve block injection. If medicines and physiotherapy do not help, an injection is given around the affected nerve in the spine.
3. Surgery. If the injection also fails, surgery follows, and in his practice that usually means small keyhole endoscopic surgery.

The trigger for imaging is time. For a patient with sciatica who takes medicines and has no relief after two weeks, he advises an X-ray and an MRI. He illustrated this with a man of 65 with sciatic pain in the leg who had tried everything without relief. The MRI showed both a badly damaged facet joint (one of the small paired joints linking the back of adjacent vertebrae) and a damaged disc, with a flap of disc pressing on the nerve.

Measure symptoms, not millimetres

One question read out in the session tested this principle directly. It described a patient with a disc space of only 7 mm who was still working, had already had two operations and had a fusion from L4 to S1, and asked at what measurement surgery becomes necessary.

Dr. Girdhar's answer was unequivocal: do not measure the millimetres; measure the patient's symptoms. The decision to operate depends on the symptoms and on the treatment the patient has already had, not on a number on the scan. The 7 mm, he said, is not the problem; pain in the leg is. If that patient is not getting relief from medicines and physiotherapy, he will need surgery to extend the fusion.

The same logic governs every step of the ladder. Imaging confirms the cause of symptoms; it does not by itself decide treatment.

Endoscopic spine surgery or microscopic tubular surgery

When surgery is needed, there are two minimally invasive routes:

• Endoscopic surgery, in which a small camera and instruments are passed through a keyhole incision and the surgeon works from a video screen.
• Microscopic tubular surgery, in which a small tube is placed down to the spine and the surgeon works through it under the operating microscope, at five to ten times magnification.

According to Dr. Girdhar, about 90% of spinal surgeries are now performed through these small incisions. The benefits he listed are less pain, very quick recovery, discharge in about a day and walking again almost immediately. The safety layers behind these operations, including neuromonitoring, are explained in spine surgery paralysis risk and the technology that reduces it.

Case: lumbar canal stenosis decompressed in 40 minutes

The patient with lumbar canal stenosis had all the nerves compressed in the centre of the canal. He could not walk for more than five minutes, had numbness in the legs and had to sit down after that distance.

Through a small endoscopic hole, Dr. Girdhar's team removed all the pressure on the nerves in a 40-minute operation. The endoscopic video showed the spinal canal opened and every nerve checked and free by the end of the procedure. That evening the patient walked a kilometre and went home.

Case: a large disc removed through a small incision

In a second case, a large disc herniation was pressing on a nerve. Through a small incision, the whole herniated fragment was removed. The patient had immediate relief from both pain and numbness. With endoscopic technique, Dr. Girdhar said, every nerve is cleared without damage, and the patient walks and goes home on the same evening.

Other minimally invasive options

Keyhole decompression is not the only technology for degenerative and painful spinal conditions. Dr. Girdhar described three more.

Kyphoplasty for spinal fractures. For a vertebral fracture, a balloon is first inserted into the collapsed vertebra and inflated to restore its height, and the cavity is then filled with bone cement. Kyphoplasty is typically used for compression fractures, most often caused by osteoporosis, and is done through small punctures in the back.

Disc replacement. Where a herniated disc is pressing on the spinal cord, the damaged disc can be removed and replaced with an artificial metal disc that continues to move. Disc replacement preserves movement at that level, in contrast to fusion, which joins the two vertebrae permanently; it is most widely used in the neck.

Spinal cord stimulation. A spinal cord stimulator consists of an electrical lead placed inside the spinal canal, connected to a small battery implanted under the skin. It is used for chronic nerve pain that has not responded to other treatment, including persistent pain after earlier spine surgery.

Costs for these procedures are listed on the microdiscectomy and discectomy cost page and the spinal decompression and fixation cost page.

Spinal fusion: recovery timeline and the adjacent level

Where the spine is unstable, as in many cases of spondylolisthesis or disc collapse, decompression alone is not enough and the vertebrae are fused. Modern fusion uses pedicle screws and a titanium or PEEK (polyetheretherketone, a strong medical plastic) cage in the disc space; Dr. Girdhar's view of older plate systems is covered in severe spinal deformity surgery.

Asked how long a patient takes to regain full mobility after fusion, he gave a precise timeline for minimally invasive and robotic surgery:

The second question from the same doctor was more challenging: why is fusion still the technique of choice if many patients later develop a slip at another level? Surgeons call this adjacent segment disease, degeneration of the level next to a fusion. Dr. Girdhar's answer was that fusion remains by far the best solution science has produced. The patients who develop a problem at another level are not the majority; drawing on about 1,000 operations a year, he said it happens in some patients, not most, and that there is a solution for it when it does.

His broader argument was about proportion. The possibility that an operation may cause a problem many years later does not justify withholding its benefit today from a patient who is in severe pain, unable to walk or becoming paralysed. Some patients will need surgery at another level after many years. He compared it with liver transplantation: a transplant carries long-term risks and may need further treatment years later, yet it is still performed, because without it the patient is very sick and suffering now.

Does nutrition affect spine health?

Dr. Girdhar links spine health to modern life: back problems are increasingly common in the computer age, driven by heavy lifting and long hours at a computer. Asked whether nutrition affects the spine, he described its three components and what each needs:

• Bones: calcium, vitamin D and sunlight.
• Muscles and soft tissues: exercise and good protein in the diet.
• Nerves: exercise and vitamin B12.

A good lifestyle, a good diet and good exercise, he said, are what keep the spine healthy.

Related reading

Herniated disc surgery is also covered from a neurosurgeon's perspective in when does a herniated disc need surgery. Dr. Girdhar's 2025 masterclass compared minimally invasive and open spine surgery, and his 2026 session explained when back and neck pain needs a spine surgeon. The questions and answers from this session are on the Live Discussion page.