The acromion is better known as the point of your shoulder and is a part of your shoulder blade. It is linked to the collar bone via the AC or acromioclavicular joint. This forms the archway of the shoulder and the rotator cuff tendons run under it. The space below the archway is known as the subacromial space.
These areas are prone to inflammation after minor injury or soft tissue degeneration. In addition, spurs of bone or calcification of local ligaments can form and cause compression of the tendons that run under them. The AC joint can also become overgrown when it is arthritic causing not only arthritic pain but local compression effects as well. These compression problems are known as impingement.
In addition, there is a natural lubricating pocket of fluid under the acromion called a bursa which can become inflamed. This is known as bursitis. The presentation of bursitis and impingement is similar with pain over the outside of your shoulder typically with an increase in pain in the mid-range.
Thankfully, inflammatory conditions in this area can often be controlled with anti-inflammatory medication and steroid injections. Usually injecting the subacromial space can be preformed without guidance but the AC joint typically requires image control to be injected.
Subsequent physiotherapy to improve shoulder blade posture and strengthen local muscles usually then leads to longer term resolution of pain. It is important to engage with physiotherapy to maximise this effect as simply relying on the injection alone will not be enough.
In cases where conservative management has failed, an operation called an arthroscopic subacromial decompression may be considered. This is a keyhole operation where a camera and instruments are introduced to the subacromial space via small incisions and the inflammatory tissue and bone spurs are removed. Where the AC joint is a significant part of the pain pattern, this joint is also removed.
As with most shoulder procedures, good rehabilitation is key to maximising your function post operatively. It is important that you engage with your physio in the post-operative phase. With decompression surgery there are minimal limitations. For comfort, a sling may be helpful but gentle motion early on is encouraged. I can discuss this with you at your consultation and post operatively. In addition, your physiotherapist can give you guidance.
Physios: see our therapy guidelines for post-operative care