What is it?
This is a collective term to describe pain felt when lifting the arm out to the side. Shoulder impingement is a symptom of several conditions which relate to the rotator cuff tendon and fluid-filled bursa (sacs) that surround the joint. These can become trapped or impinged between the head and roof of shoulder joint when the arm is lifted. Consequences of this include inflammation and wear and tear of the tendon.
Why does it occur?
There are a number of causes of shoulder impingement, which is why your surgeon will discuss it with you in detail in order to diagnose the root cause prior to initiating treatment.
Tendonitis – Overhead, repetitive activity of the shoulder joint, such as swimming or painting, can lead to inflammation and swelling of the tendon. This leaves a smaller space for the tendon to pass between the acromion and humeral head (top and bottom of the shoulder joint).
Calcific tendonitis – If calcium is deposited within the tendon this can, over time, cause irritation and create soreness and difficulty lifting the arms.
Bony spur – Also called osteophytes, these are smooth, hard bumps of extra bone that form on the ends of bones. They often pop up in the joints at the places where two bones meet. These may be present on the top of the shoulder (acromion), causing tendon irritation. This can also often occur in patients with acromioclavicular joint arthritis.
Rotator cuff tear – a partial or full tear of the rotator cuff tendon, resulting in the rubbing together of bones at the top (humeral head) and bottom (acromion) parts of the joint.
Instability – muscle imbalance can result in poor centralisation of where the top of the arm fits into the shoulder socket. Those with bone and joint abnormalities can be predisposed to this type of malalignment or imbalance.
What are the symptoms?
Pain associated with overhead use of the shoulder is among the most common symptoms, which can also be felt when lying on the side affected. Restricted movement gradually leads to difficulty performing normal, everyday tasks, such as opening overhead cupboards or carrying heavy shopping. As the shoulder is used less, owing to the pain, you may start to feel the muscles weaken.
How is it diagnosed?
A detailed history and examination will be essential to determine the nature of the injury and determine the appropriate treatment. X-rays, MRI scans and shoulder arthroscopies (keyhole investigations) can all be used to confirm your surgeon’s diagnosis.
How is it treated?
This usually resolves most shoulder impingement cases within a few weeks, and can include pain relief in the form of anti-inflammatory medications, physiotherapy, and in some cases steroid injections.
This would begin with a diagnostic shoulder arthroscopy; a type of surgery in which, using a special instrument, a very small hole or holes are made in order to look at a joint, and sometimes to repair the joint at the same time. An anaesthetic block is used to numb the arm, which can last for several hours after the procedure. You can usually return home the same day, after seeing the ward physiotherapist, who will provide you with exercises to do at home.
The One Orthopaedics team specialists
Consultant Orthopaedic Specialist FRCS (Tr & Orth)