Lumbar spinal fusion

What is lumbar spinal fusion?

Spinal fusion is an operation intended to create a bony union between two or more vertebrae. It is considered when long-term segment stability is needed, to eliminate painful abnormal movement or support correction of a deformity.^[1]

In interbody fusion, the fusion site is prepared between the vertebral bodies where the disc has been removed. The cage provides support, bone material creates conditions for fusion, and screws and rods hold the segment during this process.^[2]

Endoscopic interbody fusion in my practice

My specialisation is endoscopic and minimally invasive spine surgery. During posterior endoscopic interbody fusion, I work with a camera and instruments through small access points. I decompress nerve structures when indicated, prepare the interbody space and insert the cage endoscopically. I insert screws and rods percutaneously.^[3]

Small access points limit muscle stripping and focus work on the required area. At the same time, we plan the extent of decompression, preparation of the fusion space and implant positions as carefully as the approach itself.

Comparison of endoscopic and open approaches in interbody fusion

When we consider fusion

The decision depends on the cause of symptoms, segment stability, nerve structures and the reconstruction required. We discuss fusion in circumstances including:

• Instability or vertebral slippage requiring stabilisation.
• Degenerative changes with loss of segment support, when clinical assessment confirms the need for fusion.
• Lumbar deformity requiring a construct for correction and maintenance.
• Revision reconstructive surgery, if a stability or previous fusion problem has been identified.

We assess MRI findings alongside symptoms and examination. In stenosis, the need for additional fusion is determined separately from the need to release the nerves.^[1][7]

Spondylolysis and spondylolisthesis · Endoscopic decompression of lumbar stenosis

Which investigations are needed for planning?

For preliminary review, send what you already have. Describe where it hurts, whether pain travels into a leg, changes in walking and previous treatment.

• MRI in DICOM format: discs, nerve structures and areas of compression.
• CT, if available: bony anatomy, previous fusion and existing implants.
• X-rays: vertebral position and balance; flexion–extension images when indicated.
• Previous discharge summaries and the proposed surgical plan, if available.

If osteoporosis is suspected, we assess bone strength and the need for treatment before construct placement. This matters for screw fixation and fusion development.^[6]

How to prepare and send complete MRI/CT scans in DICOM format

Stages of endoscopic fusion

1. Planning. We select levels, approach and construct, and explain the aim of each stage.
2. Decompression when indicated. We release nerve structures from confirmed compression.
3. Preparing the interbody space. We remove the disc in the fusion area and prepare the surfaces for fusion.
4. Placing the cage and bone material. With a posterior endoscopic approach, I place the cage under endoscopic control.
5. Percutaneous fixation. Screws and rods hold the segment in the planned position.
6. Checking and starting recovery. We check construct position, assess your condition and plan initial standing.

The sequence of individual stages may differ depending on anatomy and the extent of reconstruction. Anaesthesia and preparation are agreed before surgery.^[3]

ALIF: when we discuss an anterior approach

ALIF is anterior lumbar interbody fusion. The disc is approached from the front, usually through the retroperitoneal space. This allows placement of an interbody implant from the front and the planned correction.

In my practice, ALIF is considered separately from posterior endoscopic cage placement. The choice depends on level, anatomy, previous operations and the reconstruction needed. We add percutaneous screw fixation if required.^[3][5]

More about ALIF for vertebral slippage

Preparing for fusion

Preparation must provide appropriate conditions for both surgery and subsequent fusion. After the consultation, you receive a list of investigations, anaesthetic recommendations and a plan for your regular medicines.

• Report other medical conditions, previous surgery, allergies and all medicines.
• If needed, agree osteoporosis treatment and bone preparation.
• Discuss help at home and transport home in advance.
• Clarify food, drink and medication before anaesthesia.

Before surgery, we discuss expected benefits and risks involving nerve structures, the wound, implants and fusion. These are assessed according to your condition and the extent of surgery needed.^[1]

Fusion arrangements and cost estimate

The number of levels, approach, cage, bone material and fixation system form part of interbody fusion planning. The estimate is clarified after agreeing the extent of surgery required.

• Treatment location. Agree the facility, date and admission arrangements. Where consultations and surgery take place.
• Preparation and anaesthesia. Obtain your individual investigation list and the anaesthetist's recommendations.
• Cost estimate. Clarify whether surgery, anaesthesia, required implants and materials, hospital stay and follow-up visits are included.
• Discharge and further follow-up. Agree activity advice, the review date and a team contact for questions after treatment.

Recovery after fusion

We arrange initial movement under team supervision. Staff assist with standing and walking, then we gradually increase activity. Before discharge, you receive home recommendations and a follow-up plan.

• Walking and everyday activities: safe movement and gradual increases in daily activity.
• Work and driving: return according to the agreed plan, considering exertion and medication.
• Physical work and sport: staged preparation and assessment of readiness at appointments.

Bony fusion takes months to develop. Symptoms may improve earlier. Return to full exertion is therefore determined by recovery progress and follow-up findings.^[1] A small approach helps preserve tissues, while rehabilitation also accounts for the time needed for fusion.

Questions about lumbar fusion

How does fusion differ from inserting screws?

Screws and rods hold the segment. Fusion involves the vertebrae joining through bone. The construct provides stable conditions while this biological process occurs.

Do you always use a cage?

Yes. In my endoscopic interbody fusion technique, a cage and bone material are essential. The cage provides interbody support and complements screw fixation.

How will the operation affect mobility?

Fusion involves the planned levels. Its effect on movement and everyday activity depends on the number and location of segments and the condition of the rest of the spine. We discuss these changes and rehabilitation before surgery.

Can I have an MRI after surgery?

We use only implants that permit MRI under the manufacturer's specified conditions. Before the scan, tell the MRI professional about your spinal construct.

When can I return to work?

We assess the nature of your work, recovery progress and loading on the construct. Plans differ for office and physical work; timing is agreed at follow-up visits.

What determines the cost of fusion?

The number of levels, approach, cages and fixation system, required decompression and treatment arrangements. The plan and full cost are clarified after reviewing investigations and a consultation.