Cortisone is a hormone released by the adrenal gland in response to stress. It is a potent anti-inflammatory agent. Synthetically produced cortisone is more potent and longer acting than natural cortisone and is used for diagnosis as well as treatment of a variety of musculoskeletal conditions such as tendinopathy, bursitis and arthritis.
Cortisone injections produce a significant reduction in pain and inflammation in a majority of cases. The duration and degree of the beneficial effect can vary from patient to patient. It takes about 2 to 3 days for the cortisone injection to produce any effect. In some individuals these injections may not produce any effect.
CT guided cortisone injection is an outpatient procedure performed rheumatologist or by a radiologist. For most joint injections (for example knee or shoulder) a trained rheumatologist can perform the injection at your visit, with or without ultrasound guidance. Your rheumatologist gently guides the injection into the joint, cortisone along with a local anaesthetic is injected through the needle. This may be associated with a feeling of mild discomfort. In a few cases multiple injections may be required
For some injections (eg., spinal injections) the procedure is ordered by your rheumatologist and performed by a radiologist under CT or US guidance.
The patient lies down on the Computer Tomography (CT) table. The injection site is sterilized. The radiologist then inserts the needle at the site of lesion, guided by CT Fluoroscopy imaging. Once the positioning of the needle is confirmed, cortisone along with a local anaesthetic is injected through the needle. This may be associated with a feeling of mild discomfort.
After the Procedure
You may experience pain at the site of injection once the effect of the anaesthetic wears off. The pain may last for up to 48 hours. On average cortisone requires about 36 hours to initiate its action. However this duration may vary among different patients.
Risks and Complications
The most common side effect of cortisone injection is a “cortisone flare”, a condition where cortisone crystallizes in the injected area and causes severe pain. It usually occurs in the first 24-48 hours after the injection and lasts for a couple of days. It can be managed with the help of ice packs and analgesics. Other adverse effects associated with cortisone injection may include:
- Infection at the injection site: It is a rare but serious complication and may be associated with fever along with pain and swelling at the injection site. Antibiotics may be prescribed for the management of infection.
- Transient elevation in blood sugar in patients with insulin dependent diabetes: This may last for up to 10 days. Diabetics should consult their doctor before the procedure for temporary modification of their medication.
- Redness and flushing of the face: This may occur on the second or third day of the procedure and may last for about 7 days. Antihistamines can be used if the redness fails to resolve.
- Risk of tendon rupture, if injected into a tendon
- Superficial injection may be associated with localised skin and subcutaneous fat atrophy as well as hypo-pigmentation (whitening of the skin) at the injected site