Most injections into the knee or a smaller joint, like that at the base of the thumb, are simple procedures that can be done in a doctor’s surgery. When performed by an experienced physician, the injection is only mildly uncomfortable.
First, the doctor cleans the skin in the area with an antiseptic. If the joint is puffy and filled with fluid, the doctor may insert a needle into the joint to withdraw the excess fluid and examine it. Removing the fluid rapidly relieves pain also because it reduces pressure in the joint and may speed-up healing. Next, the doctor uses a different needle to inject the corticosteroid into the joint.
Injecting a large joint, like the hip, is more complicated and may require imaging tests to help the doctor guide the needle into the joint. Experienced rheumatologists, orthopaedic surgeons, anaesthetists, and radiologists may inject the facet joints of the lower spine.