The most common cause of failed back surgery is due to nerve roots that do not heal properly. The surgery may be performed to decompress the spine, but the nerve roots do not recover. In other cases, scar tissue can form in the back, which puts pressure on the nerves and leads to serious back pain.
Misdiagnosis of a back problem can lead to a surgery that is not appropriate and does not correct the issue that is causing pain. People who experience abnormal pain behaviors before surgery can find that they do not have pain relief after. Those who have clinical depression or anxiety have a higher incidence of failed back surgeries, as do people who are medically considered poor candidates for the surgery chosen.
If the patient has a degenerative disease, even a correct diagnosis and a properly performed surgery can fail to relieve symptoms permanently. Conditions with a high level of recurrence, such as herniated discs, can mean that between five and 15% of those who have surgery will experience the condition again in the future.