The benefits from the first shot only lasted 2 weeks. The second and third set of injections lasted about 90 days. In November, I was ready to have surgery. My EMG and nerve conduction tests proved that the nerves were "sleeping" before I was. After another MRI, the neurosurgeon said I was a candidate for surgery but I was not able to get the endoscopic type surgery that is less invasive. I would have an incision about 6-8" long. Along with removing the herniation, they would have to increase the size of the hole where the nerve roots were going through.
How often cortisone injections are given varies based on the reason for the injection. This is determined on a case-by-case basis by the health care practitioner. If a single cortisone injection is curative, then further injections are unnecessary. Sometimes, a series of injections might be necessary; for example, cortisone injections for a trigger finger may be given every three weeks, to a maximum of three times in one affected finger. In other instances, such as knee osteoarthritis, a second cortisone injection may be given approximately three months after the first injection, but the injections are not generally continued on a regular basis.