Lumbar fusion is considered a major surgery in which bone grafts or metallic structures are used to make sure that the segments of vertebrae do not move with respect to one another. While it can yield a remarkable recovery from lumbar illness, it carries risks that you should know about before undertaking this type of surgery.

The most common risk of any lumbar spinal fusion is failure to relieve pain after the surgery. This happens about 20 percent of the time. The chance of this happening occurs more often when there is more than one level involved. This is called “failed back surgery syndrome”.

Vertebrae may not fuse after the surgery, in a condition called “pseudoarthrosis”. This happens about 5-10 percent of the time. Smokers have a worsened risk of fusion success. Using pedicle screws increase the risk of failure.

There can be infection, bleeding, problems with anesthesia and a risk for pulmonary embolism, which involves having blood clots in the legs after surgery that travel to the lungs with often fatal results.

Grafts done using an anterior approach with cages to hold the graft have a tendency to slip or migrate elsewhere, so that a repeat spine surgery is necessary. The revision is often done through the back rather than the front.

Nerve damage is always a possibility in spinal fusion of the lumbar spine. A patient can come out of surgery with paralysis, loss of bladder or bowel function or erectile difficulties.