•1-mL syringe with to 1 mL of 1% lidocaine for local anesthetic (or ethyl chloride or both).
•1-mL syringe with mL of 1% lidocaine mixed with mL of a triamcinolone-based corticosteroid, 40 mg/dL (or other fluorinated corticosteroid equivalent). Given the small joint size, mixing lidocaine with the corticosteroid is optional.
•3- to 5-mL syringe for joint aspiration.
•- to -inch, 25- to 26-gauge needles for injection of both anesthetic and corticosteroid/anesthetic mixture and 23- to 25-gauge needles for aspiration.
•Alcohol wipes, povidone-iodine, or chlorhexidine for sterilization.
•Sterile hemostat (optional).
•Nonsterile or sterile gloves.
•Gauze pads and an adhesive bandage.
•Appropriate tubes and slides for synovial fluid analysis.
Joint aspiration/injection is an invaluable procedure for the diagnosis and treatment of joint disease. The knee is the commonest site to require aspiration although any non-axial joint is accessible for obtaining synovial fluid. Septic arthritis and crystal arthritis can be readily diagnosed by aspirating synovial fluid. Intra-articular injection of long-acting insoluble corticosteroids produces rapid resolution of inflammation in most injected joints and is a well established procedure in rheumatological practice. The technique involves only a knowledge of basic anatomy and should not be unduly painful for the patient. Provided sterile equipment and a sensible, aseptic approach are used it is a safe procedure. This chapter addresses the indications, technical principals, expected benefits and risks of intra-articular corticosteroid injection. The use of other intra-articular injections including osmic acid, radioisotopes and hyaluronic acid, which are less universally utilised than intra-articular corticosteroid, will also be addressed.