Endoscopic and Robotic Spine Surgery

Endoscopic and robotic spine surgery are two complementary advances. In biportal endoscopy, a surgeon removes disc and bone through two incisions of under 5 mm each, watching a magnified endoscopic view on a monitor. In robotic surgery, a CT scan is used to plan every pedicle screw before it is placed, and a robotic arm lines up the drill along that planned path.

Dr. Puneet Girdhar, Chairman - Max Institute of Robotics and Minimal Invasive Spine Surgery - Ortho Spine, MIS & Robotic Spine Surgery, BLK-Max Super Speciality Hospital, New Delhi, India, uses both, and reports that about 80% of his close to 20,000 spinal operations are minimally invasive.

What a high-volume spine unit looks like

Dr. Girdhar has spent two decades in orthopaedic spine surgery. His unit at BLK-Max Super Speciality Hospital, a 650-bed hospital that operates eight surgical robots across urology, cancer surgery, gynaecology, head and neck surgery, joint replacement and spine, performs 1,200 to 1,300 spinal operations a year. He performs seven or eight operations on a typical day. The spine team has eleven surgeons, including fellows in training.

The case mix explains why the unit leans on technology. More than half of the patients arrive with disc problems: herniated discs, including fragments that have migrated up or down the canal, in the lumbar, thoracic and cervical spine, usually with significant nerve compression. Dr. Girdhar treats at least 300 patients with spondylolisthesis (a vertebra slipping forward over the one below) every year, whether the cause is degeneration or a defect in the bony arch. The unit also treats spinal canal stenosis, cervical and thoracic myelopathy (damage to the spinal cord from compression), scoliosis and kyphosis, neglected fractures and deformity left by spinal tuberculosis.

A large share of the work is corrective. The unit performs 20 to 30 revision spinal operations every month, reoperating after failed laminectomies, implant loosening or fracture, infection, adjacent segment degeneration or proximal junctional kyphosis. The unit relies on navigation, robotics, multimodal neuromonitoring, microscopes and endoscopes together, and Dr. Girdhar says that without advanced technology it would be very difficult to deliver the outcomes the unit delivers.

From open anterior surgery to an all-posterior approach

Earlier in his career Dr. Girdhar did a great deal of anterior surgery, including anterior scoliosis work and transthoracic operations for spinal tuberculosis in which a vertebral body is removed (corpectomy) through the chest. In the last ten years he has hardly performed any open anterior spinal surgery, with lumbar disc replacement the exception. Fractures, infections, myelopathy, ankylosing spondylitis and severe deformity are now handled from behind, using a retropleural approach in the thoracic spine and an extracavitary approach in the lumbar spine.

His minimally invasive work has moved in stages. For 15 to 16 years he used microscopic, tubular retractors of 16 to 20 mm for discectomy, decompression and fusion. He stopped open transforaminal lumbar interbody fusion (TLIF) in 2012; one-, two- and three-level fusions are done through a microscopic tube. Over the last year and a half the unit has moved discectomy, decompression and even TLIF for spondylolisthesis to biportal endoscopy. In his words, the incision has gone from a couple of centimetres to a few millimetres, with the least possible muscle damage. The technique is described in full in Biportal endoscopic spine surgery (UBE): discs to TLIF.

Endoscopic and robotic spine surgery: which technique does which job

The session described four groups of operation:

• Biportal endoscopy: large or migrated disc herniations, lumbar canal stenosis (including removal of the ligamentum flavum), multilevel decompression in elderly patients, and TLIF for lumbar canal stenosis with degenerative facet joint disease.
• Microscopic tubular surgery: one- to three-level fusion through a tube, with cage and screws placed through two incisions each shorter than two inches.
• Robotic pedicle screw placement: fusions of any length, revision surgery, spondylolisthesis reduction and upper cervical fixation. See robotic spine surgery for revision and complex cases.
• Osteotomy-based correction: severe deformity, where bone must be cut and the spine reshaped. See ultrasonic osteotome and spinal osteotomy types.

Neither endoscopy nor robotics replaces surgical judgement about indication. The decision about whether an operation is needed at all is covered in Indications for Spine Surgery: A Complete Guide, from an earlier Jivo Masterclass by the same surgeon.

How quickly patients recover

Dr. Girdhar reports that most of his primary patients walk the day after surgery, whether the operation was a fusion or a discectomy, and that many leave without leg pain. His typical stay is one to two days for endoscopic surgery and microdiscectomy, and three to four days at most for minimally invasive fusion. Blood loss in endoscopic decompression is under 50 mL.

One case he presented shows the pattern. A woman had a large L5-S1 disc herniation after about six months of worsening pain, limping and numbness in the foot, and could not sit comfortably. She had a biportal endoscopic discectomy through two small cuts, was discharged within a week and returned to her work.

How safe is modern spine surgery?

A common fear is nerve injury or paralysis. Dr. Girdhar's position is that at an advanced centre, injuring a nerve or the spinal cord during surgery is very rare. In the last ten years he has not seen a patient paralysed by an operation. He describes transient problems, such as hoarseness of the voice after anterior cervical surgery, which usually settle within four to six weeks, and some patchy numbness, mostly in patients who ignored a problem for a long time or whose deformity was extreme. In his account the risk is higher in those technically challenging operations than in the straightforward decompressions and stabilisations the unit does routinely. Published complication data show that the risk of a new neurological deficit rises with the complexity of the operation and is higher in major deformity correction, particularly osteotomies and vertebral column resection, than in straightforward decompression, which is why monitoring and planning matter most in those cases.

He gives two reasons why endoscopic and robotic methods lower risk. A minimally invasive, targeted approach gives a magnified view of the nerves and ligaments, whereas open surgery carries the familiar risks of dural tear and nerve injury. Robotic planning replaces estimation by eye and hand with a measured trajectory, so the learning curve is short and fellows can follow the same objective path. He is also clear that every technology has a learning curve of its own.

What surgery cannot reverse

Safety and recovery are different questions. Surgery can relieve compression and prevent further injury; it does not repair a nerve that has been destroyed.

In spinal cord injury, Dr. Girdhar says surgery has a role early on: it prevents secondary damage, stabilises the spine, relieves compression or haematoma and gives the cord the conditions in which it can recover. Partial injuries may improve over three to six months, and some patients stand and walk again. After a complete transection, with no power and no sensation, the possibility of recovery is dismal. Stabilisation still gives a patient sitting balance and makes rehabilitation possible, and rehabilitation reduces the risk of deep vein thrombosis and bedsores. A patient who asks whether robotic surgery can restore function six years after an injury that left no sensation, no power in the legs and no bladder or bowel control is given a plain no: robotic surgery makes screw placement accurate and prevents injury, it does not restore nerves.

Transverse myelitis, an inflammatory condition of the spinal cord, sits outside spine surgery altogether. In Dr. Girdhar's description it is a medical illness managed by neurologists, with cerebrospinal fluid assessment, immunotherapies, rehabilitation and, if breathing is affected, intensive care. There is no compressive lesion for a surgeon to remove.

Two procedures beyond keyhole spine surgery

Balloon kyphoplasty treats vertebral compression fractures, which are common in older patients. They occur with osteoporosis or when disease such as metastasis or myeloma weakens the bone, and often without any significant injury. Dr. Girdhar's unit performs it under local anaesthesia as a day-care procedure through two needles. A balloon is inserted into the fracture to create a cavity, so that bone is packed on all sides, and cement is then injected. The procedure takes about 20 minutes and patients walk home the same day.

Cervical disc replacement is his alternative to fusion for younger patients with a cervical disc herniation. Fusion removes motion at the operated level and shifts load to the neighbouring levels, which is the basis of concern about adjacent segment degeneration. Many of his patients ask for replacement because they want to keep full movement of the neck. He also performs lumbar disc replacement, and he removes failed prostheses placed elsewhere, as described in the article on revision and deformity surgery.

Where to go next in this series

• Biportal endoscopic spine surgery (UBE): discs to TLIF explains the technique, its instruments and the operations it now covers.
• Robotic spine surgery for revision and complex cases covers planning, accuracy and the cases where a robot adds most.
• Ultrasonic osteotome and spinal osteotomy types covers bone cutting, deformity and failed previous surgery.
• The Live Discussion records the questions put to Dr. Girdhar at the session.
• Dr. Girdhar's earlier Jivo Masterclasses are summarised in Spinal Surgery Technology: A Complete Guide and Advances in Spinal Surgery: A Complete Guide. His full profile is on the doctor page, and the orthopaedics hub lists related specialists.

For budgeting a minimally invasive fusion, see the cost guides for TLIF and microdiscectomy.