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🔬 Surgery Guide2024-01-22

Lumbar Spinal Fusion: What to Expect During Surgery

Lumbar fusion permanently joins two or more vertebrae in the lower back to eliminate painful motion. Learn what the procedure involves, types of fusion, risks, and how to prepare for surgery day.

Educational content only. This article is not medical advice. Always consult a qualified orthopedic surgeon or physician for diagnosis and treatment.

What Is Lumbar Spinal Fusion?

Lumbar spinal fusion is a surgical procedure that permanently connects two or more vertebrae in the lower back (lumbar spine) so that they heal into a single, solid bone. The goal is to eliminate motion at a painful, unstable, or compressed segment of the spine.

Fusion is not a first-line treatment — it's recommended after extensive conservative management has failed and when there is a clear structural source of pain or neurological compromise.

When Is Lumbar Fusion Performed?

Common surgical indications include:

  • Spondylolisthesis: One vertebra has slipped forward over another, causing instability and nerve compression
  • Degenerative disc disease with instability: Severely degenerated disc(s) causing disabling back pain and instability
  • Spinal stenosis with instability: Decompression alone may worsen instability, requiring fusion
  • Recurrent disc herniation: Multiple herniations at the same level
  • Spinal deformity: Significant scoliosis or kyphosis causing pain or neurological issues
  • Failed previous surgery: When prior decompression has left the spine unstable

Types of Lumbar Fusion Procedures

ALIF — Anterior Lumbar Interbody Fusion

Access through the abdomen; a large cage spacer is placed within the disc space from the front.

PLIF — Posterior Lumbar Interbody Fusion

Access from the back; disc is removed and cage is placed through the spinal canal after moving nerves aside.

TLIF — Transforaminal Lumbar Interbody Fusion

The most common approach; access through the back, one side, through the foramen, minimizing nerve retraction. Pedicle screws and rods stabilize the construct.

XLIF/LLIF — Lateral Interbody Fusion

Access through the patient's side (flank); very large cages placed with minimal disruption to back muscles.

Minimally invasive versions (MIS-TLIF, MIS-LLIF) are increasingly common, using smaller incisions and less muscle damage.

What Happens on Surgery Day

Pre-Operative Preparation

  • Arrive at the hospital 2 hours before scheduled surgery
  • NPO (nothing by mouth) since midnight
  • IV placement, monitoring, blood pressure cuff, EKG leads
  • Pre-operative antibiotics given through IV
  • Meet with anesthesiologist and surgeon

Anesthesia

Lumbar fusion is performed under general anesthesia. Procedures typically last 2–5 hours depending on the number of levels fused and approach used.

Intraoperative Steps (TLIF Example)

  1. Positioned prone (face down) on a Jackson table
  2. Intraoperative fluoroscopy (X-ray) confirms correct spinal levels
  3. Incision(s) made over the lumbar spine
  4. Muscles retracted to expose the spine
  5. Laminectomy/foraminotomy performed to decompress nerves
  6. Disc material removed from the disc space
  7. Bone graft material (from your own hip, cadaver bone, or synthetic) placed in the disc space within a cage
  8. Pedicle screws inserted into the vertebrae above and below
  9. Rods connected to screws to stabilize the segment
  10. Additional bone graft placed over the posterior elements to promote fusion
  11. Closure in layers; drain placed (removed post-op day 1 or 2)

Recovery Room

After surgery you'll spend 1–3 hours in the PACU. Multi-level fusions typically require 2–4 days of inpatient hospitalization.

Risks and Complications

Fusion is major surgery with significant risks that must be weighed carefully:

  • Pseudoarthrosis (failed fusion): Bone does not fully join (~10–20%); may require revision
  • Adjacent segment disease: Increased stress on levels adjacent to the fusion can accelerate degeneration
  • Hardware failure: Screws or rods can break or loosen before fusion is complete
  • Infection: Wound or deep spinal infection (<2%)
  • Nerve damage: Worsening pain, weakness, or numbness
  • Blood loss: Fusion surgery carries higher blood loss risk than decompression alone
  • Blood clots (DVT/PE)
  • Persistent pain: Fusion reliably treats instability; back pain relief is less predictable

What to Bring to the Hospital

  • Comfortable loose clothing (pajama pants with elastic waist)
  • Slip-on shoes
  • Toiletries
  • Entertainment (books, tablet)
  • Phone charger
  • Insurance cards, photo ID
  • Medication list
  • Arrange 2–4 weeks of help at home post-discharge