What are the causes of sudden shoulder pain without injury?
Acute shoulder pain without a history of trauma can be very limiting, interfering with daily activities, sleep and exercise. There are a few recognised causes for this. The article will describe the possible causes and the treatment options.
Relevant shoulder anatomy
The main shoulder joint (also referred to as the glenohumeral joint) is a ball and socket-type joint. The ball is formed by the humeral head (the arm bone), and the socket is formed by the glenoid (part of the shoulder blade that articulates with the humerus). The shoulder joint is surrounded by a thin layer of tissue (called a joint capsule). There is another smaller joint above the shoulder called the acromioclavicular (AC) joint. This is located between the collar bone (clavicle) and part of the shoulder blade (called the acromion).
The space between the two joints (the glenohumeral and AC joints) is called “the sub-acromial space”. It is very important as it accommodates a number of key structures, namely the subacromial bursa and the rotator cuff tendons. A bursa is a thin fluid-containing sac usually seen adjacent to a bone to provide cushioning effect and protection. The shoulder bursa is one of the largest in our body and is called (the subacromial bursa). The rotator cuff tendons (mainly the supraspinatus tendon) run between the bursa and the ball of the shoulder joint. These tendons are very essential for shoulder movements and stability.
What are the causes of atraumatic shoulder pain?
The two main causes of shoulder pain without injury are:
Calcific tendonitis (calcific tendinopathy) is the deposition of calcium material within the rotator cuff tendons.
What is the cause of shoulder calcification?
The exact aetiology of calcific tendinitis is not fully understood. It is more common in diabetic patients and in women between the age of 40 and 60 years. It is also more common in people who use their arms excessively, like manual workers and athletes. Deposition of calcium is also reported following trauma.
How to diagnose shoulder calcific tendonitis?
When the condition is suspected clinically, a shoulder Ultrasound scan is an excellent modality for the assessment. It can readily visualise and measure the size of the area of calcification within the rotator cuff tendons. A shoulder X-ray can be performed if there is uncertainty about the diagnosis, as it is excellent in picking up calcification. The benefit of ultrasound is that it can also guide a barbotage-lavage procedure.
What is the treatment for shoulder calcific tendonitis?
Usually, shoulder calcific tendonitis is self-limiting and managed by rest, physiotherapy and anti-inflammatory tablets. However, it may take some time to settle down.
What if conservative management is not working?
If your shoulder pain is not responding to conservative management, ultrasound-guided injection therapy is a well-recognised treatment option. There are two types of injection therapy:
1: Ultrasound-guided sub-acromial bursa steroid injection
2: Ultrasound-guided barbotage-lavage
What is shoulder barbotage-lavage for calcific tendonitis?
In this procedure, Aspiration or breaking down of the calcium material is accurately attempted under ultrasound guidance using a special needle. This is combined with a subacromial bursa steroid and local anaesthetic injection. To find out more, please see our article ultrasound guided barbotage-lavage
Frozen shoulder (sometimes called adhesive capsulitis) is a specific shoulder condition characterised by inflammation and stiffness of the shoulder joint capsule. The shoulder joint is surrounded by a thin layer of tissue (called a joint capsule). In a Frozen shoulder, the inflamed and stiff joint capsule will cause pain and restrict shoulder movement. The condition is usually associated with shoulder pain that can significantly interfere with activities and sleep.
What are the causes/risk factors for frozen shoulder?
The cause and mechanism for frozen shoulder are not clear. It can be seen after a shoulder injury or shoulder surgery. It is more common in diabetic patients, patients with inflammatory arthritis and Dupuytren’s contracture.
How is a frozen shoulder diagnosed?
Frozen shoulder is mainly a clinical diagnosis. So, the diagnosis is usually established based on the clinical findings. Imaging like shoulder ultrasound and MRI are mainly used to rule out other causes of shoulder pain, like rotator cuff tear, shoulder osteoarthritis and shoulder calcification (calcific tendonitis). An X-ray will be normal in a frozen shoulder.
How to treat frozen shoulder?
The treatment usually starts with conservative management, including physiotherapy, activity modification and anti-inflammatory tablets. To find out more, read our article about treatment options for a frozen shoulder.
Do shoulder injections help with a frozen shoulder?
If the symptoms are severe and not responding to the measures described above, particularly if the pain is affecting sleep, daily activities and sport, then a shoulder injection can be helpful. This will be useful in achieving efficient rehabilitation. There are mainly two types of injections that can be used to treat frozen shoulder
Hydrodistension is a special procedure used to treat frozen shoulder/adhesive capsulitis. In addition to injecting cortisone and numbing medicine, a high volume of sterile (clean) water (approx. 20 mls) will be injected inside the shoulder joint under ultrasound guidance. This aims to distend the inflamed and thickened joint capsule and reduce the inflammation via the steroid effect. To find out more, please see our article about shoulder hydrodistension.
What other conditions can cause sudden onset shoulder pain?
Other causes for sudden shoulder pain are less common than the above two. They include:
Acute brachial neuritis
Shoulder conditions and treatments