LLIF (Lateral Lumbar Interbody Fusion)

Overview

LLIF — Lateral Lumbar Interbody Fusion (also known as XLIF or DLIF depending on the specific system) — is a minimally invasive fusion technique that accesses the lumbar spine through a small incision on the patient's side (flank). The approach passes through the retroperitoneal space behind the abdominal contents and through the psoas muscle to reach the lateral aspect of the lumbar spine. This lateral corridor allows for placement of a very large interbody cage that spans the entire width of the vertebral body — from one side to the other — providing excellent stability and indirect decompression of the nerves. Because the cage restores disc height, the narrowed foramina (nerve openings) are indirectly opened, often eliminating the need for a direct posterior decompression. Dr. Basques uses real-time intraoperative neuromonitoring to safely navigate through the psoas muscle without injuring the nerves of the lumbar plexus.

How It Works

Under general anesthesia, the patient is positioned on their side with the affected disc level marked by X-ray. A small incision (about 3–4 cm) is made on the flank. Dilators are sequentially passed through the retroperitoneal space and through the psoas muscle to dock on the lateral aspect of the disc. Intraoperative neuromonitoring (EMG) ensures the corridor avoids the lumbar plexus nerves. A tubular retractor is placed, and the disc space is accessed. Dr. Basques performs a complete discectomy and prepares the disc space. A large interbody cage packed with bone graft is inserted — spanning from side to side across the vertebral body. The cage restores disc height, which indirectly decompresses the foramen. If posterior stabilization is needed, percutaneous pedicle screws are placed either in the same position or after repositioning. The lateral incision is closed with a few stitches.

Benefits

Who Is a Candidate?

Ideal candidates have degenerative disc disease, spondylolisthesis, or foraminal stenosis at L1-L5 levels that would benefit from indirect decompression and fusion. LLIF works best from L1-L2 through L4-L5. It cannot be used at L5-S1 because the iliac crest (pelvis) blocks the lateral approach. The L4-L5 level requires careful assessment of the iliac crest height. Patients with significant central stenosis or large disc herniations may still require direct posterior decompression. Dr. Basques evaluates each patient's anatomy with standing X-rays and MRI.

Recovery & Aftercare

Hospital stay is typically 1–2 days. Walking begins the day after surgery. A brief period of activity modification is required. Transient thigh numbness or hip flexor weakness occurs in a small percentage of patients and typically resolves within weeks. Return to desk work is typically 3–4 weeks. No heavy lifting for the first 6–8 weeks. Dr. Basques monitors patients closely for any approach-related symptoms.

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