For a patient with a diagnosis of rotator cuff tendinitis, where is the appropriate location for a corticosteroid injection?

In cases of rotator cuff tendinitis, the subacromial space is the most appropriate site for a corticosteroid injection. This area is located beneath the acromion and above the rotator cuff tendons. When inflammation occurs in the rotator cuff, it can lead to pain and limited range of motion, particularly during overhead activities.

Injecting corticosteroids into the subacromial space can help reduce inflammation in the rotator cuff tendons and the surrounding bursa, providing significant pain relief and improving function. This approach directly targets the area where tendinitis and associated bursitis commonly occur, allowing for effective management of symptoms.

While the glenohumeral joint, acromioclavicular joint, and bicipital groove are related structures in the shoulder region, they are not the primary sites for targeting inflammation related to rotator cuff tendinitis. The glenohumeral joint injection typically addresses issues like arthritis or isolated glenohumeral conditions rather than tendon inflammation. Acromioclavicular joint injections are focused on conditions affecting that specific joint, and the bicipital groove injection would be targeting issues related to the long head of the biceps rather than the rotator cuff itself.