The procedure for injection therapy is uncomplicated and well established. The object is to inject the corticosteroid preparation with as little pain and as few complications as possible. The technique is similar for muscle, periarticular, or articular injections. Selection of the site and careful attention to surface and deep anatomy are of paramount importance. [ 20 ] Injections in the vicinity of known nerve or arterial landmarks should not be attempted. For example, a lateral epicondyle injection is relatively easy. An injection into at the medial epicondyle (near the ulnar nerve) carries greater risk, and extra care must be taken to identify the nerve, outline its course, and avoid it.
An epidural steroid injection places this powerful anti-inflammatory medication directly around the spinal nerves. Traditionally epidural injections were administered without any special equipment, by inserting the needle by feel in the area around the spinal nerves. More recently epidural injections have been administered with the aid of imaging tools to allow your physician to see the needle going to the proper location. Either real-time x-ray, called fluoroscopy, or CT scan can be used to 'watch' the needle deliver the medication to the proper location.
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.