SUBACROMIAL IMPINGEMENT & BURSITIS
Impingement is a syndrome in the shoulder caused by an abutment (grinding) of the humeral head (ball part of the shoulder joint) against the undersurface of the acromion (shelf of bone that protects the outer part of the shoulder, the shoulder tip). It is commonly associated with an inflammation of a lubricating sac in the shoulder called the bursa. The bursa can get very unhappy and inflamed if there is continued grinding associated with impingement, and this manifests as pain in the lateral shoulder with shoulder height activities and commonly crunching in the shoulder.
It is poorly understood why people get impingement but it is very common. It is thought to come about as a consequence of anatomical, biological and behavioural factors. Not everyone suffers from impingement and there are a few risk factors.
The anatomy of the bone which sits atop the shoulder joint (the acromion) is thought to contribute to the development of impingement. Some people develop a spur under the bone which can dig into the top of the tendon, causing mechanical irritation.
Biologically, the decline in muscle tone and strength in the muscles which surround the shoulder probably cause some mild instability in the shoulder thus leading to grinding of the humeral head against the undersurface of the acromion. Hence a lot of the treatment for impingement is centred on improving muscular control of the shoulder. This means physio, physio, physio.
Behavioural factors can include work activities involving repeated overhead work. Leisure activities such as weights (particularly inclined bench presses and push ups) can trigger the onset of a bursitis.
Treatment in the first instance consists of simple measures such as anti-inflammatory medications, movement therapy (strengthening with a physio) and hydrotherapy, hot packs, avoiding movements that cause pain and occasional injections into the subacromial space with steroid medication.
When these simple measures fail then surgery can be considered. This usually incorporates an acromioplasty - a procedure to trim away the bone spur under the shoulder tip. Acromio is short for acromion and plasty is short for changing the shape of. This is performed using a telescope.
Rehabilitation involves once again - physio, physio, physio.
We can change the shape of the bone to make things as structurally sound as possible but if the shoulder muscles are weak, then the ball part of the shoulder will still grind. Hence physio, physio.
Some people will be as good as gold in a matter of weeks, for others it can take months of physio to get the shoulder good again.