The potential complications specific to a spinal fusion procedure depend in part on the surgical technique used. These can include:
- Postoperative wound infection is the most common complication, occurring in about 1-5% of cases. The risk of a postoperative infection is higher when metallic fixation is used, and is also higher in diabetic and overweight patients.
- Pain from the bone graft site in the pelvis, if used, is very common for the first 6 to 8 weeks following surgery. Some amount of this pain may persist and become chronic in 15 to 30% of cases.
- Failure of bone healing of the fusion (“pseudo-arthrosis”) can occur in 5 to 40% of cases, depending on the specific surgical technique used and the patient’s individual risk factors. If metallic implants were used and the fusion does not heal, this will eventually result in loosening or breakage of the screws or rods, as they are not meant to be relied upon to stabilize the spine indefinitely.
Persistent pain due to failure of the bone to fuse will often necessitate additional surgery to get the fusion to heal. Revision fusion surgery is commonly larger than the initial procedure, and may have added risk. The patient’s individual risk factors also play a role in fusion rates. For example, patients who smoke have lower fusion rates. Again, discussing and understanding all of the surgical risks and complications of any recommended fusion procedure is critical.
Are there Long-Term Negative Consequences of Spinal Fusion?
As a result of stiffening of the operative spinal segment(s) with spinal fusion, added stress with spine motion is placed on the remaining mobile discs above and below the fusion. This may accelerate the process of disc degeneration of adjacent discs, and at some point in the future additional surgery may be needed to the surrounding discs due to pain from degeneration, instability, or nerve compression.
This process is sometimes called “adjacent segment disease” or “transitional syndrome”, and it remains somewhat controversial just how much increased the rate of adjacent disc degeneration is attributable to the fusion and aftereffects, versus what amount of degeneration of the other discs would have occurred naturally without a spinal fusion.