Surgery for Spondylolisthesis, Stenosis and Spine Fractures

Surgery for spondylolisthesis, lumbar stenosis and spinal fractures now rests on three minimally invasive operations: a transforaminal lumbar interbody fusion (TLIF) through tubes and percutaneous screws for an unstable slip, a decompression that preserves the facet joints for stenosis, and cement augmentation, with or without screw fixation, for a collapsing vertebra. Each matches a specific indication.

Dr. Puneet Girdhar, then Vice Chairman & Head, Spine Surgery at BLK-Max Super Speciality Hospital, New Delhi, India, has treated thousands of patients with spondylolisthesis by minimally invasive technique, and for him a TLIF is almost always minimally invasive. This article sets out how he chooses between these operations and what each involves, using the cases he presented. Which patients need surgery in the first place is covered in the complete guide to indications for spine surgery, and when to refer them in when back and neck pain needs a spine surgeon.

Spondylolisthesis surgery: reduce, decompress, fuse

Spondylolisthesis is the forward slip of one vertebra on the one below. It is graded by how far the vertebra has slipped, from grade 1 (a small slip) to grade 4 and beyond. A slip compresses the exiting nerves in the foramina, the openings at the side of the spine through which nerve roots leave the canal, and the resulting leg pain is what usually brings the patient to surgery.

A high-grade slip in a young woman

Dr. Girdhar presented a woman in her mid-thirties with a grade 3 to grade 4 slip. She had six months of pain radiating into the leg, with an acute worsening over the previous month, and no therapy had helped. Her imaging showed a lytic slip (one caused by a defect in the bony arch) of L4 on L5, with L5 sacralised (partly fused to the sacrum), and clear compression of the nerve in the foramen.

Several options exist today for such a patient, including endoscopic decompression and stabilisation. For Dr. Girdhar, the operation is almost always a minimally invasive TLIF. The result he showed from a patient operated in early 2026 was a complete reduction of L4 on L5, from grade 3 back to normal alignment, with the cage sitting centrally in the disc space. The entire operation was done through four small incisions. There was no midline incision, no muscle stripping and no blood transfusion.

How a minimally invasive TLIF is done

A TLIF fuses two vertebrae by inserting a cage into the disc space from one side, through the foramen, and fixing the segment with screws. In the minimally invasive version (MIS TLIF), Dr. Girdhar works through tubes of 18 to 20 mm with the operating microscope locked on top:

1. Pedicle screws are placed percutaneously, through the skin, over guidewires.
2. Through the tube, the surgeon starts at the junction of the lamina and the facet joint and removes the facet (a facetectomy), decompressing the exiting nerve.
3. The surgeon identifies Kambin's triangle, the safe working corridor into the disc space bounded by the exiting nerve root, the traversing nerve root and the vertebra below, and passes the cage through it.
4. Screw extenders allow the slip to be reduced and the rods to be placed without opening the back.

He described the technique as one that needs a full workshop to learn properly, but the principle is simple: everything an open TLIF does, done without detaching the paraspinal muscles. His answer on how surgeons whose setting does not yet perform minimally invasive surgery can adopt it is recorded in the Live Discussion.

Why he avoids posterolateral fusion alone

Dr. Girdhar performs open TLIF very rarely, and opens a patient mainly in revision surgery, where the new construct has to be connected to an existing rod. Even then, decompression at new levels can be done by minimally invasive technique. He avoids posterolateral fusion on its own, without an interbody cage, because it can lead to implant failure. The spine needs anterior support: his standard is 360-degree stabilisation and fusion, with a cage in front and screws behind.

The second principle is sagittal correction. A fusion must restore lumbar lordosis, the normal inward curve of the lower back, to reduce the stress on the levels above. Expandable cages help restore both disc height and lordosis, and the newer designs carry 12 degrees of built-in lordosis.

When the slip spans two levels

A second case showed the same approach at greater scale. A patient who had travelled from overseas with a dysplastic spondylolisthesis, a slip caused by a congenital malformation of the facet joints, was in severe pain from stenosis of the foramina on both sides. Dr. Girdhar performed a two-level TLIF with bilateral minimally invasive decompression. The patient was walking from the next day and was discharged within days of the operation.

Robotic pedicle screw placement

Minimally invasive screws can be placed with X-ray guidance alone, but Dr. Girdhar described robotics as giving an extraordinary gain in accuracy and safety, saving operating time and, above all, cutting the repeated X-ray exposure that minimal access surgery otherwise entails. His centre acquired its spinal robot about three and a half years before the masterclass and has since performed more than 500 robotic procedures.

The workflow has four steps:

1. Imaging and registration. A reference frame is fixed to the spine and a 3D scan is taken in theatre, so that the robot's software knows exactly where the spine is.
2. Planning. On the 3D images, the surgeon places each virtual screw: the level, entry point, trajectory, length and diameter. Each screw is checked on axial, sagittal and coronal views to confirm it stays clear of the canal and the nerve roots and away from the facet joint, and on the 3D image to confirm it has good bone purchase, which matters especially in osteoporotic bone.
3. Alignment. The robotic arm moves itself to the planned trajectory and guides the skin incision.
4. Execution. The surgeon drills and inserts the screw through the arm while watching the screen, where the planned screw and the screw being inserted are shown in different colours. In the case Dr. Girdhar showed, the two overlapped completely on every view.

Robotics is most useful where the anatomy is distorted. In revision surgery after a laminectomy, with a collapsed disc or a slip that makes freehand landmarks unreliable, the robot allows precise, medially placed screws, after which facetectomy, decompression and a cage can follow through two small incisions. Dr. Girdhar also uses the robot for C1-C2 fixation, where the bony elements are small and a screw passes from C2 into C1. With the arm holding the planned trajectory, he uses a power drill to place these screws.

Lumbar canal stenosis: decompression without fusion

Lumbar canal stenosis is a narrowing of the spinal canal, usually from thickened ligament, enlarged facet joints and a bulging disc. It causes neurogenic claudication: leg pain, numbness or heaviness on walking, relieved by sitting or bending forward.

The traditional operation was a laminectomy, removing the roof of the canal. Dr. Girdhar pointed out that this leads to considerable additional instability. His centre now treats stenosis through a tube with an over-the-top decompression, technically a unilateral laminotomy for bilateral decompression:

• The surgeon enters on one side at the junction of the spinous process and lamina and removes the ligamentum flavum on that side.
• The dura is gently retracted and the drill is angled across, under the base of the spinous process, to the opposite lamina.
• The ligamentum flavum on the far side is removed last, freeing the dural sac and both nerve roots.

The facet joints on both sides are preserved, so the spinal canal is widened significantly without the need for fixation.

The same over-the-top decompression can be done with a uniportal endoscope, a biportal endoscope or the microtubular technique that Dr. Girdhar uses every day. His centre does not treat one or two level stenosis with open surgery. The decision rule is straightforward:

Biportal endoscopy for decompression and fusion

Biportal endoscopy is the newest technique in Dr. Girdhar's practice, which adopted it in the year before the masterclass. Two small ports are made on the same side of the spine, one for the endoscope and one for instruments, so the operation resembles a knee arthroscopy. The working medium is saline rather than air, and the view comes through the endoscope rather than the microscope. Radiofrequency energy clears soft tissue, and a high-speed burr performs the laminotomy so that the ligamentum flavum can be released.

In the video he showed, the dural sac and both nerve roots were fully decompressed through two small cuts, with the ligamentum flavum removed from the opposite side by the over-the-top route. Compared with a single-port endoscope, the biportal technique, in his description, makes it possible to insert cages, so discectomies and TLIFs can both be performed this way.

Spine fractures: when cement is enough and when fixation is needed

Vertebral cementing is close to a daily procedure in Dr. Girdhar's practice. The patients are mostly elderly, with osteoporotic fractures or with vertebrae weakened by secondary disease such as metastasis or myeloma, which leads to collapse and severe back pain. In balloon kyphoplasty, a balloon is inflated inside the fractured vertebra and the cavity is filled with bone cement.

Cement stabilises the vertebra immediately. The procedure is done under local anaesthesia as a day-care operation: a patient who arrives at the clinic or emergency department in severe pain can walk out of the hospital the same day.

Cement alone, however, has limits. Where there is a burst fracture, with the edges of the vertebra broken on all sides, or involvement of the posterior ligamentous complex, or a pathology that makes the whole vertebra unstable, cement cannot hold the spine. These patients need minimally invasive screw fixation, with cement delivered through the fixation. Fractures in patients with ankylosing spondylitis, including Andersson lesions (destructive lesions through the disc and vertebra in a rigid, fused spine), are operated under neuromonitoring.

The safety tools behind every operation

Dr. Girdhar gives much of the credit for modern outcomes to technology rather than technique alone:

• Multimodal neuromonitoring tracks motor and somatosensory evoked potentials (signals that test the motor and sensory pathways of the spinal cord) and free-running and triggered electromyography (EMG, the electrical activity of the muscles) throughout surgery. It is used in every deformity correction and allows the surgeon to locate the step responsible if any signal changes.
• Intraoperative 3D imaging behaves like a CT scanner in the operating theatre.
• The operating microscope gives a magnified, illuminated view, and Dr. Girdhar rarely operates without one.
• Ultrasonic bone osteotomes make precise cuts close to the spinal cord and preserve the removed bone for use as graft.
• Pain interventions such as radiofrequency ablation of the facet joint nerves are used by the pain team for selected patients with back pain, and spinal cord stimulators are used sparingly for neuropathic pain.
• Cervical disc replacement remains an option for younger patients with cervical disc disease.

Treatment-cost guidance for these operations is on the pages for TLIF, spinal decompression and fixation and discectomy. For a closer comparison of minimally invasive and open surgery from Dr. Girdhar's August 2025 masterclass, see minimally invasive vs open spine surgery. Deformity and revision surgery are covered in revision spine surgery and neglected spinal deformity.