Lateral Lumbar Interbody Fusion (LLIF)

LLIF is a lumbar fusion technique performed through the side of the body. By approaching the spine laterally through the psoas muscle, a large interbody cage can be placed without disrupting the posterior spinal muscles or ligaments. Posterior fixation with screws is sometimes added.

LLIF may be appropriate for degenerative disc disease, spondylolisthesis, or mild deformity — particularly when indirect decompression through disc height restoration and ligamentotaxis is expected to relieve symptoms.

The lateral approach has real advantages — larger cages, better disc height restoration, and less posterior muscle disruption. But it's not right for every level or every patient. The approach through the psoas carries a risk of nerve injury, and not every problem can be adequately addressed with indirect decompression. When direct decompression of the nerves is needed, a different approach may be more appropriate.

• Thigh numbness or hip flexor weakness (psoas-related)
• Nerve injury
• Vascular injury
• Cage subsidence
• Nonunion
• Need for supplemental posterior fixation

Most patients are discharged within one to two days. Hip flexor soreness or thigh numbness may occur and typically resolves over weeks. Return to activity varies, but light activity is usually resumed within a few weeks.