This article is the third in a 12-part series. The topic of the series is commonly injected joints. The focus of this report is the shoulder. Shoulder pain can be difficult to diagnose. An injection can help isolate and treat the problem. A numbing agent like Novocain is used. It is combined with a steroid to reduce inflammation.
There are three sites in the shoulder region that can be injected. These include the glenohumeral (GH) joint, the acromioclavicular (AC) joint, and the subacromial space.
The location and anatomy of each of these sites are described. Supplies needed for each area are provided. Needle size, specific drugs, and medication dosages for each are also included.
The authors offer reasons for their instructions. For example, a triamcinolone-based steroid is used for the GH. It is the longest lasting injectable corticosteroid. A nonfluorinated corticosteroid is used for the subacromial space. It reduces the risk of tissue loss and skin changes.
Patient position and placement of the needle are described. The examiner is told how to use the surface anatomy to feel for the exact spot to inject. If there is fluid in the joint, it is aspirated (drawn out) first before injecting the drugs.
The procedure is done with sterile technique. The skin is anesthetized (numbed) so the patient does not feel the injection. Synovial fluid from inside the joint is sent to the lab for analysis. This information can help with the diagnosis and treatment plan.
The authors provide other pearls (tips) as well. For example, positioning of the patient and examiner is described that allows easier needle entrance into the joint.
A popping sensation is not uncommon when injecting the subacromial space. This is caused by the needle entering the bursa. The bursa is a small fluid-filled sac. It’s located where a muscle or tendon slides across bone. Th bursa is a cushion to reduce friction between the two moving surfaces.