When Does a Herniated Disc Need Surgery? Surgical Options

A herniated disc needs early surgery when red flags appear, namely bladder or bowel involvement, gross limb weakness or foot drop. Surgery is also worth considering when conservative care is failing, for example when a patient still needs two or three painkillers a day or cannot walk 500 metres. Most patients improve on physiotherapy, painkillers and rest, and the operation, when it is needed, is chosen to fit the disc.

Spine surgery has moved in one direction: less exposure, less muscle disruption and faster return to normal movement. Dr. Anil Kumar Kansal, Vice Chairman & HOD - Neuro Surgery & Neuro Spine, BLK-Max Super Speciality Hospital, New Delhi, India, covers the full sequence in his neuro spine surgery practice, from a percutaneous procedure for a contained disc to robot-guided screw placement. What gives his approach its shape is not the technology but the selection: each technique is matched to a specific anatomical situation, and conservative treatment is given a defined place before any of them.

Herniated disc symptoms and MRI diagnosis

A herniated disc, in which part of a spinal disc pushes out of place and presses on a nerve, is recognised clinically and confirmed by MRI.

The clinical picture

A disc herniation typically announces itself as neck or back pain that starts localised to the affected level and then spreads into a limb, on the right or the left. Numbness and tingling follow, and then weakness. In some patients bladder and bowel function is involved. Dr. Kansal's working rule is that pain which radiates, combined with a neurological deficit, calls for imaging.

MRI is the investigation

X-rays and other tests can be done first, but MRI is the investigation that settles the question. It distinguishes a minor bulge from a major one and shows which side and which nerve root is compressed. In one of the scans he presented, a prolapsed disc was pressing on the nerves on the right side.

When does a herniated disc need surgery? Red flags and thresholds

Conservative treatment comes first, and three red flags override it. Most patients begin with physiotherapy, painkillers, muscle relaxants and rest, with physiotherapy modalities such as ultrasonic diathermy and TENS (transcutaneous electrical nerve stimulation). A period of bed rest can be added. In Dr. Kansal's experience most patients are relieved by these measures, and treatment simply continues.

The red flags that change the plan are specific:

• Bladder or bowel involvement, meaning difficulty passing urine or opening the bowels.
• Gross weakness in the limb.
• Foot drop, an inability to lift the front of the foot.

Any of these moves the patient towards early surgery rather than a further trial of conservative care.

A threshold for the patient who is managing, but only just

The harder decision is the patient without red flags who is coping on tablets. Consider a woman of 65 with nerve compression who could continue on physiotherapy and medication, but whose remaining years might be pain-free after an operation. Dr. Kansal uses two tests.

1. How much pain, measured in tablets and distance. If the patient needs two or three painkillers a day, cannot carry out daily activities or cannot walk 500 metres, surgery is worth considering.
2. Whether there is a neurological deficit. Weakness of the limbs or bladder and bowel involvement leads him to advise surgery.

When either applies, his view is that the long-term result and the finances are both better with surgery, because long-term medication will cost the same or more after some time.

Percutaneous vs endoscopic discectomy: matching the operation to the disc

The type of disc decides the operation: a contained disc can be treated percutaneously, while other discs that need surgery are removed through a small incision under the microscope.

Percutaneous surgery for the contained disc

For a contained disc, where the herniated material remains within the disc, a percutaneous approach is possible. The patient lies on the side and the instrument is passed into the disc through the skin under imaging guidance to remove the fragment and free the nerve. Percutaneous discectomy is usually performed under fluoroscopic X-ray control, a live X-ray image. Dr. Kansal is explicit that this procedure is only for contained discs.

Endoscopic and minimally invasive discectomy

When surgery is needed, his preference is a minimally invasive operation through a small incision. Sequential dilators open a narrow corridor, soft tissue at the base is cleared with cautery, and the rest of the operation is done under the microscope. The steps he showed on video are the standard ones performed through a much smaller window:

• the ligamentum flavum, the ligament lining the back of the spinal canal, is cut to reach the canal;
• a nerve root retractor moves the root aside;
• the annulus, the tough outer ring of the disc, is opened and the compressing disc removed;
• the extruded fragment that has migrated below the nerve root is retrieved.

Once the compressing material is out, patients usually do well. Quotations from Indian hospitals for this operation are summarised under microdiscectomy and discectomy cost.

Kyphoplasty for osteoporotic compression fractures

Kyphoplasty is a small procedure that places cement inside a fractured vertebra, and it suits osteoporotic fractures in which the back wall of the vertebral body is intact. Vertebral compression fractures are common in osteoporotic bone, particularly in older patients, and can also occur secondary to other disease. The vertebral body collapses, which is visible on X-ray and MRI.

The traditional management was bed rest with calcium and vitamin D, and drugs to strengthen bone such as parathyroid hormone or calcitonin. Dr. Kansal's objection to relying on this alone is twofold. Osteoporotic and osteopenic fractures heal with difficulty, and they are painful. And if the patient walks regularly before the fracture has healed, the vertebra can collapse further and compress the nerves, producing a neurological deficit.

Kyphoplasty addresses both problems. He describes two advantages:

• Rapid pain relief. About 90 percent of the fracture pain goes immediately after the cement is placed.
• Next-day mobilisation. The patient can be up from the following day and return to normal daily activities.

The selection criterion is anatomical. Kyphoplasty works best in an osteoporotic fracture where the posterior margin of the vertebral body is intact and there is no compression of the spinal cord or nerve roots.

Cervical disc replacement: surgery that preserves neck movement

Artificial cervical disc replacement removes a damaged neck disc and replaces it with an implant that keeps the level mobile, so the patient can move the neck from the first day. A cervical disc that compresses the spinal canal can cause neck pain and radiating arm pain, then weakness in both the arms and the legs, difficulty walking and sometimes bladder and bowel involvement. Conservative treatment is tried first.

Where surgery is needed, artificial disc replacement is Dr. Kansal's latest approach for suitable patients. Through an incision in the front of the neck, the disc is removed, retractors hold the space open, the last of the disc material is cleared and the artificial disc is placed in the space created. X-ray then confirms movement at the replaced level.

The case for replacement is functional:

• the patient can move the neck from the first day;
• there is no need to wear a collar for a long period;
• neck mobility returns early, and with it an early return to work.

Odontoid fracture fixation with a single screw

A fracture of the odontoid, the peg of the second cervical vertebra (C2), can be fixed with one screw while preserving neck movement. The fracture causes severe neck pain. Dr. Kansal's technique is a single screw passed from the front through the body of C2, across the fracture line and into the odontoid. One screw fixes the fracture and the patient's spinal movement is preserved. That matters at this level in particular: the joint between the first and second cervical vertebrae provides roughly half of the neck's rotation, which a posterior fusion would sacrifice.

Robotic spine surgery: accuracy, cost and limits

Robotic assistance in spine surgery places screws exactly where they are planned, and Dr. Kansal reports that it brings screw misplacement under 1%.

What the robot does

Robotic assistance has entered spine surgery for one purpose: placing screws and fixation exactly where they are planned. It also reduces intraoperative radiation exposure for the patient, the surgeon and the theatre staff.

The workflow at BLK-Max, as Dr. Kansal showed it, runs in four steps:

1. The patient's imaging data, a CT scan and 3D X-rays, are loaded into the system and matched to each other.
2. The surgeon plans each screw on the images, including the angle of approach.
3. The robotic arm moves into position and guides the trajectory.
4. Screws are inserted with continuous 3D visualisation of where each one is going.

The post-operative images he showed had the screws sitting in the positions planned before surgery.

What it changes for the patient

The screws are not absorbable. They stay in place for life, which is why their position matters. With robotic guidance, Dr. Kansal reports that screw misplacement falls to under 1%. His argument for the technology rests on that figure: an operation can be technically good in every other respect, but one misplaced screw can cost the whole procedure its value. With accurate placement he sees no screw-related nerve pain and no complication from the hardware.

At his centre, robotic assistance adds about USD 1,000 to 2,000 to a spine operation that costs around USD 7,000. Given what it protects against, he does not regard the difference as significant. His answers to audience questions on screws, success rates and cost are in the masterclass Live Discussion.

Where it stops

At present the robot only places screws. The rest of the operation remains in the surgeon's hands. As the technology matures, Dr. Kansal expects it to help with other parts of the operation as well. Its use for electrode placement in the brain is covered in brain tumour surgery techniques, from navigation to Gamma Knife.

For the contraindications, timing principles and costs that apply across all of these procedures, see the complete guide to recent advances in neurosurgery.