Injections to the shoulder can be performed either for diagnostic purposes or for aspiration of joint fluid. This can be done for evaluation of possible infection or crystalline arthritis.
Injections for therapeutic reasons are often used to place a corticosteroid into the joints or subacromial space. Knowing the basic anatomy and surface landmarks of the shoulder for the subacromial space, glenohumeral joint, and AC joint is critically important for safe and effective joint aspiration or injection. Injections should be performed under aseptic conditions with thorough preparation of the skin and using sterile technique. Local anesthetic can be given at the time of injection and is often helpful in localizing the shoulder pain, particularly if the injection is precisely given into a specific compartment and followed by re-examination of the shoulder soon after the injection.