Cortisone or corticosteroid injections are commonly given to reduce the pain and inflammation at the site of injection. The cortisone shots are widely given in the knee and the shoulder joint, but may be given in other joints as well. The injection may be given in the elbows, hips, ankle, wrist, spine, etc.
The injection is most commonly given for osteoarthritis by orthopedic surgeons. The injection may also be used for joint pain caused by inflammatory arthritis such as rheumatoid arthritis and psoriatic arthritis. The shots may also be given for painful joint conditions such as gout. The steroid injections are helpful in back pain and inflammation of bursae and tendons.
Mechanism of action
The injections contain a steroid medication that is delivered locally in the joint, tendon, or bursae. The adrenal glands naturally release the steroid in the body. The steroids help to dampen the immune system and reduce inflammation. The reduction in inflammation leads to relief from pain and swelling.
The cortisone shots are usually a part of a broader treatment plan, including physical therapy, cold/heat therapy, etc. The shots are given locally in specific areas of the body, so minimum levels reach the entire body. On the contrary, systemic steroids, although suppress the inflammation but may lead to long term side effects. The local cortisone injections create increased concentration at the site leading to more powerful anti-inflammatory action.
The patients may receive a cortisone shot in the doctor’s office as an outpatient procedure. Before the procedure, the physician ensures that the patient is not on any blood thinners and is not having any active infection. Diabetic patients must have their blood sugar levels well-controlled before the shot as the blood sugar levels may shoot up after the injection.
The patient is positioned for easy access to the involved joint. The site of injection and the adjacent area is cleaned with a povidone-iodine solution. Numbing medication is applied to the location of injection, to make it the injection less painful.
The physician marks the site of needle insertion with a sterile marker, and the injection is delivered. The injection site is covered with a sterile dressing. Often the physician might also use ultrasound guidance to deliver the injection at the correct location.
Post injection, the patient is advised to apply ice and take over the counter nonsteroidal anti-inflammatory and pain medications as needed for 1-3 days. Pain and redness are common short term side effects after injections and usually subside within 1-2 days. Patients are advised to keep the dressing dry for at least a day and avoid hot tub baths for a day. The patients are also encouraged to watch for any signs of infection.
Frequent cortisone shots are avoided as they may cause long term damage to the cartilage of the joint. The local steroid may also cause the death of the nearby bone and thinning/weakening of the bone. The cortisone may cause thinning of the skin and the adjoining soft tissues.
The steroid injection may be associated with an increased risk of joint infection and damage to the surrounding nerves. Multiple steroid injections may cause tendons to weaken and rupture. Immediately after the injection, there may be increased pain and inflammation, which is easily managed with pain relievers. There may be temporary facial redness, and the blood sugar may shoot up in diabetic patients.
The anti-inflammatory effect of the cortisone shot which results in pain relief may take a few days to kick in. The majority of the patients experience significant relief after a few days. The reduction in pain and swelling may last for several months or even a year. However, some patients may need repeated cortisone shots as the drug effect wears off.