There is a small chance that surgery by fusion may not help the patient. This may happen if the fusion fails or if the patient has pain due to symptoms other than what the fusion has been done for. Exacerbation needs to be re-investigated to find the cause of pain. Occasionally, the patient may start having issues at a different level after being relieved at the symptomatic level after surgery. In such a case, the patients need to be managed for a different level accordingly.