Advances in Spinal Surgery

The main advances in spinal surgery are the move from open incisions to microscopic tubular surgery and biportal endoscopy, supported by intraoperative 3D imaging, robotics, neuromonitoring and ultrasonic bone cutting. The principles of spine surgery have not changed: decompress the neural elements, stabilise what is unstable, restore balance. What has changed, almost completely, is how those goals are reached.

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, has performed more than 16,000 spinal operations, and he describes the surgery he was trained in and the surgery he performs today as two different poles of the same discipline. At BLK-Max, a 650-bed hospital with 24 operating theatres, he has run the spine service for 16 years and built it into a centre for orthopaedic spine surgery, robotic spine surgery and spinal deformity correction.

This guide sets out how the field has moved, the technology that now surrounds a spinal operation, the signals that should prompt a referral, and what it takes to deliver complex spinal care safely.

Advances in spinal surgery: from the open incision to the keyhole

Spine surgery has moved through five stages: open surgery, loupes, the operating microscope, tubular surgery and endoscopy. Dr. Girdhar belongs to the generation of spine surgeons who lived through every one of them, and the sequence explains why modern outcomes look so different.

Open surgery. During his postgraduate training, the standard approach was to open the entire back. Long midline incisions stripped the paraspinal muscles from the bone to give the surgeon a view. He now does this very rarely.

Loupes. The first step towards magnification was surgical loupes. Their limitation is ergonomic and optical at once: loupes do not give a static image, so the surgeon keeps moving the neck throughout the operation to hold focus on the area of interest. Dr. Girdhar recalls worrying about his own neck in that era.

The operating microscope. The microscope is now his everyday workhorse. It gives illumination, magnification and coaxial vision, and he regards it as a mandatory part of any spine surgery training programme today. He trained through a period when a microscope was not part of postgraduate training at all.

Tubular surgery. After returning from training in the United States with Dr. Kevin Foley, a pioneer of microscopic tubular techniques, he began performing tubular surgery, in which the operation is done through a narrow tube passed between the back muscles, in 2012. For 12 to 13 years he has done every operation he can through a minimally invasive microtubular approach.

Endoscopy. The most recent step is endoscopic surgery, performed with a small camera passed into the spine. Dr. Girdhar is clear about the limits: an endoscope cannot take care of every pathology at all times. Biportal endoscopy, the newest addition, changes that calculation. In his assessment it can take care of around 90 per cent of spinal work.

How biportal endoscopy works

Biportal endoscopy behaves less like the familiar single-channel spinal endoscope and more like arthroscopy of the knee or shoulder. It works in a fluid medium of normal saline rather than in a gas-filled cavity, as laparoscopy of the abdomen does. Two ports are placed. One carries the camera and the light source. The other admits the surgeon's normal spinal instruments, the same instruments used in open or tubular surgery. Separating the optics from the working channel is what gives the technique its range: the surgeon is not confined to instruments threaded down the scope, and the saline keeps the field clear.

The practical result is what the patient sees: two small ports, a couple of sutures, and in many cases a return home the next day. The degenerative operations performed this way, from disc removal to decompression and stabilisation, are covered in the minimally invasive surgery article.

The technology stack around a modern spinal operation

Modern spine surgery relies on a stack of technologies, each with a defined job. Dr. Girdhar's position is that technology exists to make spine surgery not only safe but precise, accurate and as minimally invasive as the pathology allows. His department works with a broad set of tools:

• Microscopic tubular surgery for almost all degenerative cases. Open approaches are reserved for multi-level disease or large scoliotic and kyphotic deformities that require removal of an entire vertebra, and even then the microscope often remains in use.
• Endoscopic surgery, including biportal endoscopy.
• Intraoperative 3D imaging, which feeds the navigation and robotic systems.
• Multimodal intraoperative neuromonitoring, which he treats as a workhorse in every deformity case.
• Ultrasonic bone cutters in place of hammer and chisel.
• Robotics, used on an everyday basis for three years for implant work: screws and cages.
• Cementing procedures such as kyphoplasty, in which a collapsed vertebra is lifted and filled with bone cement, and cervical disc replacement.
• Interventional pain techniques, including nerve blocks, facet joint blocks and radiofrequency ablation performed with the pain management team.
• Spinal cord stimulators for neuropathic pain.

The last item carries an ethical boundary that Dr. Girdhar states plainly. Spinal cord stimulation is used for neuropathic pain. It is not used to promise recovery from paralysis.

Why ultrasonic bone cutting matters

An ultrasonic bone cutter, or osteotome, makes spine surgery safer by cutting bone precisely while sparing nerves. It illustrates how a single tool can change the risk profile of an operation. It cuts bone by ultrasonic vibration rather than by rotation or impact. Dr. Girdhar describes three advantages. It cuts precisely, almost like a pen, so the surgeon does not chisel or destroy bone. It works at a lower temperature than a high-speed drill, so the bone it removes stays healthy enough to be used as autograft, which spares the patient a separate graft harvest. And it cuts mineralised bone selectively: the moment it touches a neural element such as the dural sac, it stops, protecting nerves and the pedicles that later hold the screws. In the most demanding deformity corrections, where an entire vertebra must be removed around the spinal cord, these properties are central to the operation rather than incidental.

Neuromonitoring as a safety record

Intraoperative neuromonitoring tracks the function of the spinal cord and nerves throughout an operation. In deformity surgery Dr. Girdhar monitors somatosensory evoked potentials, free-running and triggered electromyography, and motor evoked potentials throughout the operation. Multimodal neuromonitoring is widely regarded as standard practice in spinal deformity surgery, and it serves two purposes. It keeps the surgeon alert to any potential neural injury as it develops, and it guides the reversible steps if a change occurs. It also creates a medico-legal record of what happened during the operation and how any problem was handled. Most cases pass without a significant event, but the record exists for every case.

Technology versus freehand feel in spine surgery

Many surgeons believe that placing screws freehand gives them more control. Dr. Girdhar compares this to the common perception that driving a car feels safer than flying, when air travel is in fact far safer, precisely because aviation relies on navigation systems and air traffic control rather than on individual feel. In his view, data on spinal navigation and robotics point the same way: an objective, technology-supported approach, backed by a good team, produces consistently safe implant placement, and does so across a surgical team regardless of each surgeon's years of experience.

Technology does not replace judgement: decompression, reduction and the restoration of balance remain the surgeon's work. The navigation and robotics article sets out where that line falls, along with the robotic workflow and the accuracy he reports.

When to refer a patient to a spine specialist

Refer a patient with back pain when four to six weeks of medical management has failed, when symptoms progress sooner, when severe pain accompanies MRI changes, or before a neurological deficit such as foot drop develops. Backache is ubiquitous. Dr. Girdhar points out that it reaches every specialty: a gastroenterologist may see a patient with liver disease whose back pain stems from secondary osteoporosis, and poor musculature alone can cause it. Most patients are managed conservatively and well at their local centres. The question for the treating doctor is when that stops being enough. His referral thresholds are specific:

• Failure of medical management. A patient who has had four to six weeks of medical management without any response should be referred.
• Progression before six weeks. If new or advancing symptoms appear while conservative treatment is under way, such as numbness, weakness, gait disturbance or pain the patient cannot bear, referral should be early, without waiting for the six weeks to elapse.
• Severe pain with MRI changes. When a patient whose MRI shows changes reports severe, pronounced back pain, Dr. Girdhar asks for lateral X-rays taken bending forward and backward to test whether the spine is stable, an approach illustrated by a case in the companion article on minimally invasive surgery.
• Neurological deficit. He prefers to intervene before a foot drop (weakness that stops the patient lifting the front of the foot) develops, not after.

Specific conditions carry their own thresholds. Neurogenic claudication from lumbar canal stenosis that has not responded in two to three months, cervical disc disease with loss of grip or pinch, osteoporotic collapse in a postmenopausal woman, and any hemivertebra in a young child each have a defined point for referral, set out in the companion articles.

Addressing the patient's fear

Patients often arrive afraid of surgery. Many have seen relatives or friends go through large open spine operations that were debilitating, with damage to normal muscles and to the facet joints and other structures that give the back its strength and allow upright posture. They worry about paralysis, about whether a foot drop will recover, and about needing further operations. Dr. Girdhar's answer is that the options have changed. For one-level and two-level disease with instability, stenosis or disc problems he no longer performs the open procedure at all; he uses minimally invasive surgery, and he manages slips of grade two and grade three, and even severe deformities, the same way.

What complex spinal care requires: volume, team and training

High-volume practice underpins these outcomes. Dr. Girdhar performs about 1,100 spinal operations a year, 90 to 100 a month, with a minimum of four to six cases on each list and more than 20 operating days a month. His department includes associate and attending spine surgeons, a dedicated spine operating suite and a Diplomate of National Board fellowship programme, which trains two fellows at a time over two years.

The most complex operations depend on more than the surgeon. The largest deformity corrections run to many hours and require intensive care, anaesthesia and a theatre team built around them; the deformity article sets out why Dr. Girdhar insists they belong only at a dedicated high-volume centre.

Training reflects the same demand. Dr. Girdhar observes that in 13 or 14 years of training orthopaedic fellows, none has chosen spine surgery as a career. Through a scope everything is tiny, the learning curve is steep, and the margin for error is close to nil. Since starting his dedicated spine fellowship four years ago, his fellows work only in spine theatres, and responsibility for every outcome remains with him.

Spine surgery for patients who travel from abroad

Minimally invasive surgery suits patients who travel. Most walk the day after surgery, wounds are small, and sutures or staples can be removed in the patient's home town or home country.

Dr. Girdhar has, by his estimate, operated on a few hundred patients from Africa, including more than a dozen from Congo since the previous winter. One recent patient, a woman referred by her doctor in West Africa, had a slip of L4 over L5 beyond grade two with a completely collapsed disc, excruciating buttock pain and numbness in both legs that forced her to sit down when she walked. Through small incisions, with robotic placement of percutaneous screws, decompression and a cage, the slip was reduced and the disc height restored. She went home one week after surgery.