The principal risk of this type of surgery is that a solid fusion will not be obtained (nonunion) and further surgery to re-fuse the spine may be necessary. Most fusion will set up within three months, and will continue to get stronger for one to two years. Once a solid fusion is achieved it is very unlikely that it will ever break.

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 10% and 40% 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.

In skilled hands, this is a very safe procedure. Possible reported risks and complications of posterior cervical fusion may include but are not limited to:

• Non-union
• Damage to the spinal cord or nerve roots
• Infection
• Bleeding
• Continued pain
• Adjacent disc disease
• Injury to the vertebral artery
• Blood clots
• Stroke
• Paralysis
• Bowel or bladder incontinence
• Death