Spondylolysis and spondylolisthesis

Endoscopic treatment of spondylolisthesis: nerve decompression and spinal stability

My specialty is endoscopic spine surgery. For spondylolisthesis, I plan treatment around two aims: relieving compression of the neural structures and, when necessary, stabilizing the affected segment.

The endoscope provides a magnified view of the surgical area and allows work through small approaches. When interbody fusion is needed, I use endoscopic cage placement through a posterior approach and percutaneous screw fixation. Another option for cage placement is the anterior ALIF approach, selected according to anatomy and the aims of surgery.^[3]

At your consultation, you will receive an explanation of which structures are causing symptoms, why each stage of treatment is needed and how recovery will be organized.

Spondylolysis and spondylolisthesis: what is the difference?

Spondylolysis is a defect in the part of the vertebral arch also called the pars interarticularis. It can develop as a result of repetitive loading and a stress injury to bone. The arch defect can exist without vertebral slippage.

Spondylolisthesis is the displacement of one vertebra relative to its neighbour. It may be associated with spondylolysis or have another cause. These diagnoses therefore do not imply the same treatment.^[1]

Isthmic spondylolisthesis

Associated with a defect in the vertebral arch. Planning depends on the degree of slippage, disc condition and the openings through which the nerve roots exit.

Degenerative spondylolisthesis

Associated with changes in the disc, joints and ligaments. It often occurs together with spinal canal stenosis. Nerve compression and movement at the segment are assessed separately.^[2]

When to discuss surgery

Consult a spine surgeon if pain interferes with work, walking or sleep, numbness or weakness develops in a leg, and treatment has not provided enough relief. During examination, we check strength, sensation and reflexes and compare them with the images.

The decision depends on the cause of symptoms, changes over time and the impact of the condition on your life. The grade of slippage on an X-ray helps describe the condition, but does not determine the entire surgical plan by itself.^[2]

Which investigations are needed for a slipped vertebra?

For preliminary review, send existing MRI/CT studies and X-rays, their reports and a brief description of symptoms. State where it hurts, whether you have leg pain and how far you can walk without stopping.

• MRI shows the neural structures, discs and areas of narrowing.
• Standing X-rays help assess vertebral position under load. Flexion and extension views are needed when indicated.
• CT clarifies the bone defect and anatomy for surgical planning.
• Assessment of bone quality may be necessary before implant placement.

We determine the need for additional investigations after consultation.^[2] Send complete MRI/CT series in DICOM, rather than photographs of the images alone. After previous surgery, include the discharge summary and implant details.

Step-by-step instructions: preparing and sending MRI/CT studies in DICOM format

Endoscopic decompression: when nerves can be released without fixation

If leg pain and limited walking are caused by nerve compression, decompression removes the tissue creating that pressure. The BESS/UBE biportal endoscopic approach allows this work to be performed under camera guidance through small approaches.

Not everyone with degenerative spondylolisthesis needs stabilization. We assess instability, deformity and how much tissue must be removed to fully release the nerves.^[4]

In the Nordsten-DS study, decompression without fusion was non-inferior to combined surgery after five years in the studied group of patients with degenerative slippage. Isthmic spondylolisthesis with an arch defect was not included in this group. The result cannot automatically be applied to every type of slippage.^[5]

Endoscopic fusion: a cage and percutaneous screws

When stabilization is needed, we combine nerve decompression with interbody fusion. The aim of this operation is to achieve bony union between the selected vertebrae.

• Decompression releases the neural structures.
• An interbody cage provides support between the vertebral bodies and maintains the interbody space.
• Bone material creates the conditions for fusion to develop.
• Screws and rods hold the selected segment while this process takes place.

In my practice, posterior cage placement is performed endoscopically, and screws are placed percutaneously.^[3] The small approach limits muscle stripping. Fusion involves joining the selected segment: we discuss this stage separately from the method of access.

More about endoscopic fusion, cages and screw fixation

ALIF: when we consider anterior cage placement

ALIF is anterior lumbar interbody fusion. The disc is approached from the front, through the abdominal region. This approach may help restore interbody height and the lumbar profile. When necessary, we combine it with decompression and percutaneous fixation.

When considering ALIF, we take into account the level of slippage, vascular anatomy and previous operations. ALIF and posterior endoscopic cage placement are different approaches; at consultation, I will explain which fits your plan.^[3]

Is surgery always necessary for spondylolysis and spondylolisthesis?

No. For spondylolysis without significant slippage, particularly in young patients with a recent stress injury, adjusting activity, rehabilitation and monitoring healing are important. Return to sport is agreed after assessing the condition.^[1]

For slippage without significant symptoms, observation and selected treatment may be sufficient. If symptoms persist, we will discuss a surgical way to address their cause.

From initial contact to surgery

1. Send your investigations. Complete MRI/CT studies in DICOM format, X-rays, reports and a description of symptoms. Preliminary review is free.
2. Attend a consultation and examination. We clarify the cause of pain, the condition of the nerves and segmental stability.
3. Agree on a plan. Decompression, endoscopic fusion or ALIF, with an explanation of the extent required and the implants.
4. Prepare for the procedure. Receive a list of investigations, advice on medication and a pain management plan.
5. Return to activity. We agree on activity levels, follow-up examinations and rehabilitation.

Recovery after decompression and stabilization

We prepare a recovery plan for the extent of your surgery and your usual activity. After the procedure, the team helps you start moving, and before discharge you receive instructions for home.

• Walking and daily activities: gradually increasing activity and safe ways to perform everyday movements.
• Office work and driving: we agree on returning according to how you feel, your journey and medication use.
• Physical work and sport: a step-by-step activity plan and assessment of readiness.

After fusion, bony union develops over months. Early pain relief and return to full activity are therefore different stages. Follow-up examinations help increase activity at the appropriate time.^[2]

Questions about surgery for spondylolisthesis

Are screws always necessary for a slipped vertebra?

Not always. If decompression is sufficient and there are no indications for stabilization, surgery without fixation can be discussed. In fusion, screws have a different role: holding the segment that needs to unite.

Must the slippage be completely corrected on the images?

The extent of correction is planned according to vertebral position, the condition of the nerves and spinal balance. The priority is to achieve the treatment goals while taking your anatomy into account.

Is MRI alone sufficient to choose an operation?

MRI is important for assessing nerves, but planning may also require standing X-rays, flexion-extension views or CT. Send what you already have; we will clarify the need for additional investigations at consultation.

Can I seek help after previous open surgery?

Yes. Send current investigations in DICOM format, a discharge summary and information about the implanted construct. We will assess the cause of new or persistent symptoms and the possible extent of revision surgery.

Will movement be preserved after fusion?

Movement is eliminated in the segments that need to unite. The effect on everyday activity depends on the number of levels and the condition of the rest of the spine. We discuss this during planning.

What determines the cost of surgery?

The extent of decompression required, number of levels, approach, implants and treatment facility. After reviewing your investigations, we will agree on a plan and cost estimate.