A cortisone shot (corticosteroid injection) is a common and effective treatment for localized pain and swelling within the shoulder joint. This procedure delivers potent anti-inflammatory medication directly to the source of discomfort, offering relief that is more targeted than oral anti-inflammatory drugs. The precise location of the injection is determined by the underlying cause of the patient’s shoulder pain.
Identifying Target Locations in the Shoulder
The location of a cortisone injection is chosen to target the specific inflamed tissue within the shoulder. The most frequent injection site is the subacromial space, which lies beneath the acromion (the bony prominence at the top of the shoulder blade). This space contains the subacromial bursa and the rotator cuff tendons, making it the preferred target for conditions like shoulder impingement syndrome, rotator cuff tendinitis, and bursitis.
Another common area is the acromioclavicular (AC) joint, which connects the collarbone (clavicle) to the shoulder blade (scapula). An injection here addresses pain caused by arthritis or inflammation within this small joint. When pain originates deeper within the main ball-and-socket joint, known as the glenohumeral joint, the injection is placed directly into the joint capsule. This approach is used for treating severe osteoarthritis or adhesive capsulitis, often called “frozen shoulder.”
The Purpose of Steroid Injections
The primary goal of administering a corticosteroid injection is to significantly reduce inflammation. Corticosteroids are synthetic versions of cortisol, a naturally occurring steroid hormone. They work by suppressing the body’s immune response in the targeted area, which limits the accumulation of inflammatory cells and reduces the permeability of blood vessels. This action decreases the swelling, redness, and pain characteristic of inflammation.
By calming this local inflammatory reaction, the injection provides a window of opportunity for the patient to pursue physical therapy and rehabilitation with less discomfort. The medication does not repair structural damage, but it provides relief that lasts for several weeks to months. This localized therapy commonly treats subacromial bursitis, rotator cuff tendinopathy, and various forms of shoulder arthritis when oral medications fail to provide sufficient relief.
The Injection Procedure and Techniques
The shoulder injection is performed as an in-office procedure, beginning with the cleaning and sterilizing of the skin around the injection site. The cortisone medication is mixed with a local anesthetic, such as lidocaine, which provides immediate, temporary pain relief. The quick-acting anesthetic helps the clinician confirm that the needle has reached the correct pain source.
To ensure accurate placement within the small, targeted structures of the shoulder, the procedure utilizes guidance from imaging technology. Ultrasound or fluoroscopy (a type of real-time X-ray) allows the clinician to visualize the needle’s path and confirm precise medication delivery. This precision maximizes the drug’s effect and avoids delicate structures like tendons. Following the injection, some patients may experience a temporary increase in pain, swelling, and irritation known as a “steroid flare,” which lasts up to 48 hours.
Immediate Post-Injection Care
After the injection, patients are advised to protect the treated shoulder for one to two days. This means avoiding strenuous activity, heavy lifting, or repetitive movements that strain the joint. While the initial pain relief from the anesthetic wears off quickly, the full anti-inflammatory effects of the corticosteroid begin within 72 hours.
Applying ice to the injection site as needed helps manage mild soreness or discomfort immediately following the procedure. Patients should avoid applying heat (such as heating pads or hot tubs) for at least 24 hours, as this can worsen inflammation. Monitoring the area for signs of infection, such as increasing pain, redness, or swelling that lasts beyond 48 hours, is recommended.