21st December 2008 By
The condition is characterised by severe pain and loss of movement in the shoulder. There are 2 types, it can be either primary (known as idiopathic) where the onset of symptoms is spontaneous or secondary where the condition follows a specific traumatic event, such as a tendon injury or after fracture. There is a spectrum of severity.
Frozen shoulder is more common in females and tends to occur between the ages 40 and 60. Frozen shoulder is more common in patients with diabetes, but the cause of this is unknown. Symptoms generally resolve on their own over time though this can be up to 3 years. However some reports state that improvement only occurs in 65% of patients.
It is characterised by three phases. The length of each phase is variable.
It begins with gradual onset of pain (painful phase) which can be severe, particularly at night. Patients usually complain of ‘jerk’ pain where sudden or unexpected movements produce severe exacerbations of pain. This can last several weeks to months.
Next the shoulder becomes stiff (freezing phase), this stiffness occurs in all directions of movement but the trademark feature is a reduction in external rotation as shown in the picture below. The pain can reduce at this stage but this is not always the case. The duration can be over 12 months.
Finally the movement of the shoulder improves (thawing phase), this is often slow and gradual. There is some debate about whether all patients return to normal function.
The hallmark of the condition is pain and stiffness with restriction of both active and passive movements of the shoulder. This, alongside a normal x-ray, is how we make the diagnosis. MRI or ultrasound scan are usually normal unless there is suspicion of a rotator cuff tear as the underlying cause.
The shoulder is stiff because the shoulder capsule (lining) forms a contracture. This limits the available space that the shoulder has to move in.
All treatments must be compared to the natural history of the condition. In the painful phase physiotherapy may aggravate the situation. There is a likelihood of some inflammatory component in this stage, so an early steroid injection into the shoulder (glenohumeral) joint can be beneficial.
Until pain begins to resolve exercises of the shoulder are best kept to within comfortable range of motion of the shoulder (see pendular and active assist exercise sheets). If pain is beginning to resolve then more aggressive stretching can be performed.
The timing of intervention is controversial. But if the shoulder is stiff and painful and there are no signs of improvement then intervention can be considered usually at 9-12 months after onset of symptoms.
The aim of treatment is to return the release the contracted capsule to allow better movement. There are a few techniques used such as: manipulation under anaesthetic; hydrodilatation or surgical release.
We favour surgical release by an arthroscopic (keyhole surgery) technique of the contracted tissue. This allows more precision than manipulation and results in less postoperative pain. Afterwards intensive physiotherapy is required to maintain the increased movement that is gained at surgery.
GSSS November 2011