Risks include:

• Nerve Injury
• Adjacent disc disease
• Infection
• Bleeding
• Non-union

The PLIF and TLIF approach has an advantage over the posterolateral gutter fusion in that the large spinal muscles do not need to be dissected off the transverse processes, so there is less scarring of the muscle and associated pain for the patient. The major advantage of PLIF and TLIF is that there is significantly more surface area for fusion in the disc space as compared to the posterolateral gutter.

However, the PLIF requires substantial retraction of the nerve roots to gain access to the disc space. Significant traction can injure the nerve root and has the potential to result in chronic leg pain and back pain. The pain associated with this type of nerve root injury can be severe, and there are no effective options for treatment. The TLIF requires less retraction of the dural sac, but nerve injury can occur at the level of the nerve cell bodies (dorsal root ganglion). Pain associated with manipulation of the DRG can also be very severe and debilitating. Fortunately, these complications are rare with meticulous care of the nerves.

There are numerous veins (epidural veins) over the disc space, and surgery in this area creates the potential for excessive blood loss during the surgery.

Recurrent pain after a successful spinal fusion procedure is more likely due to a "transfer" lesion at the motion segment above or below the fusion, because stress is transferred to the next level and may cause that vertebral segment to degenerate and breakdown.

Nonunion rates of between 0% and 20% have been quoted in the medical literature. Nonunion rates are higher for patients who have had prior surgery, patients who smoke or are obese, patients who have multiple level fusion surgery, and for patients who have been treated with radiation for cancer.

Other than nonunion, the risks of a spinal fusion surgery include infection or bleeding. These complications are fairly uncommon (approximately 1% to 3% occurrence).