Indications for Two-Level Spinal Fusion

Multilevel fusion as a primary treatment for low back pain from degenerated discs is a controversial topic in spine medicine. In general, lumbar spine fusion has a relatively poor success rate for treatment of multi-level disc degeneration seen on MRI scans1. Patients who are considering multilevel spinal fusion for treatment of low back pain are well advised to carefully research their options.

When to Perform a Multilevel Fusion for Low Back Pain

While fusion for two levels may at times be a reasonable consideration, fusion of three or more levels of the spine is quite rarely, if ever, a good option for the patient.

Two-level fusion. A two-level fusion may be considered for patients with severe, disabling pain that occurs at two levels of the spine (e.g. L4-L5 and L5-S1), but only after extensive non-surgical and pain management approaches have been tried.

Three-level fusion. As a rule, three-level fusions for treatment of low back pain from lumbar degenerated discs are rarely advisable for three main reasons:

  • Uncertain outcomes. With fusion at three or more levels of the spine, there is a significant risk that the surgery will not improve the patient’s pain.
  • Too much rigidity. Three level fusions limit movement and flexibility in the patient’s back so much that this rigidity is likely to cause ongoing pain for the patient.
  • Adjacent level degeneration. Extensive fusion of the lumbar spine transfers stress to the next level of the spine, which is thought to put that next level at risk for degeneration. For example, a fusion from L3 through S1 would put the L2-L3 level of the spine at risk for degeneration and causing future pain.

Because of the above, some physicians believe that lumbar degenerative disc disease at three or more levels of the spine means that fusion surgery is not an option. Instead, patients with severe pain and degeneration at three or more levels of the spine are often advised to enter a comprehensive pain management program.

The considerations against having a three-level fusion can also be applied to a two-level fusion, but to a lesser extent.


Multilevel Fusion for Other Conditions

Unlike spinal fusion for treatment of low back pain, multilevel fusion for the following conditions is not controversial:

  • Spinal deformity. One common indication for multilevel fusion is for the treatment of spinal deformity, including scoliosis (side curvature of the spine), and kyphosis (excessive forward bending of the spine).

  • Spondylolisthesis. This condition, which occurs when one vertebra slips forward over the one below it, typically causes leg pain and other symptoms and if it is symptomatic at more than one level of the spine, a fusion at each level may be considered.

    For more information, see Spondylolithesis Information.

  • Rare spinal disorders. Multilevel spinal fusions are often performed in the treatment of the less commonly conditions that can affect more than one level of the spine, including fractures, tumors, and infections of the spine.


  • 1.Lumbar Spine Fusion in the Treatment of Degenerative Conditions: Current Indications... Herkowitz and Sidhu J Am Acad Orthop Surg.1995; 3: 123-135.