Frozen shoulder is a condition where a shoulder becomes stiff and painful, usually for no apparent reason and it lasts a long time. But what is it really? And what can be done about it?
Frozen shoulder is more technically called adhesive capsulitis. ‘Adhesive’ suggests that the issue is ‘sticky’ and ‘capsulitis’ refers to ‘inflammation of the joint capsule’.
A joint is where a bone meets a bone, ligaments are thick connective tissues holding the bones together, and the capsule is a thinner connective tissue that encases the whole joint. Ligaments will blend into the capsule, as will tendons which join muscle to bone. Synovial fluid will sit within the joint capsule to help lubricate and nourish the joint.
The sticky concept of adhesive capsulitis suggests the joint motion is stuck and stiff earlier into its range of motion, as opposed to a normal, freely moving joint with non-painful tightness at end of its range. Inflammation is a chemical reaction that is irritating. In the case of adhesive capsulitis, the shoulder joint capsule particularly in certain locations, becomes inflamed and the connective tissue becomes thick and tight. The space within the capsule becomes smaller and makes it difficult to move the shoulder joint as normal.
Consider the difference of wearing a jumper that is made of elastic material that easily stretches around the shoulder so you can reach anywhere you like, versus wearing a tight jacket that is too small, making it hard to lift up your arms or reach behind your back. Combine this lack of mobility with pain that is associated with the inflammation, and you have a stiff and sore shoulder.
The simplistic concept of a frozen shoulder is that the shoulder first freezes, then is frozen, then thaws. This relates to the initial phase of the shoulder becoming stiff and increasingly painful, in some cases the pain can be extreme. There is a turning point where the pain abates leaving the shoulder stiff but minimally sore. Followed by thawing which is the recovery phase - this latter phase was once believed to be a spontaneous process after 1-2 years, but it isn’t, for some it lasts much much longer, for others it doesn’t.
Why do frozen shoulders occur?
It is not known with certainty why. In many cases they happen for no apparent reason. Cases of what are called secondary frozen shoulder, occur after something else has happened e.g. a fractured shoulder or after shoulder surgery. Versus primary frozen shoulders appear out of nowhere – there are other conditions and demographics more associated with frozen shoulder e.g. the classic is a middle-aged woman and in her non-dominant arm. There are also associations with metabolic diseases and auto-immune conditions like type 2 diabetes, heart disease, and hyperthyroidism. It is also associated with Dupuytren’s contracture which is a similar thickening and tightening of the connective tissue in the palm of the hand.
In the experience of the author over 30 years of physiotherapy practice, the middle-aged female is the most common presenting patient, usually their non dominant shoulder, which can in subsequent years present in their dominant shoulder. Most of these women do not have clear metabolic and autoimmune tendencies suggested by the literature, rather they are fit and active in the prime of their lives and careers and the condition can be debilitating.
How do you diagnose frozen shoulder?
In the hands of an experienced clinician, the condition is quite obvious:
Onset of a painful and stiff shoulder for no apparent reason
Or onset following an apparent trauma where the response is disproportionate to the incident e.g. reaching into the back or the car
Usually, onset is in the non-dominant arm, between ages of 40-60 in women more than men
Pain will be around or inside the shoulder joint, diffuse and frequently radiates into the upper arm and even down to the wrist
Movement restriction will initially be reaching upwards and behind the back but will extend to restriction in EVERY direction
The stiffness usually results in the top of the shoulder riding up towards the neck when try to raise the arm which can result in secondary neck pain
Strength is typically preserved in pain-free parts of shoulder movement e.g. can still carry shopping bags or carry a box at waist level
Loss of range of motion is both active and passive i.e. someone else cannot move your shoulder much or any further into range than you can on your own
Investigations such as X-rays and ultrasound scans are not always necessary, however, in the absence of a co-existing conditions radiology will frequently come back with no abnormalities, which will support the diagnosis based on taking a thorough history and physical examination. An MRI or USS may report a thickened coracoacromial ligament or thickened rotator interval.
Frozen shoulder can be misdiagnosed – not all stiff shoulders are frozen shoulders
If a subacromial bursitis is reported on MRI or USS it may or may not be relevant - if it is, it won’t be the reason for a markedly stiff shoulder, but can contribute to a mildly stiff shoulder and its definitely painful and usually weak
Rotator cuff related shoulder pain such as rotator cuff tears or tendinopathy can present as stiff, but similar to bursitis, motion loss is usually mild, and it doesn’t get progressive worse followed by pain improving. It will be weak in specific directions and pain may range from minimal to marked.
Sometimes very weak shoulders such as those with a large rotator cuff tears may appear stiff, but only with attempt to lift the arm independently – when you assist the patients arm to lift it may in fact have full range of motion. These patients are also more likely to be elderly with degenerative tendons that tear with minimal force or at any age following significant trauma.
Osteoarthritis of the shoulder can mimic a frozen shoulder due to the pattern of stiffness being in every direction, however the onset will be much more gradual over years, is often crunchy and catchy, and may or may not be painful. If it becomes a painful condition, it is usually at a later stage of worsening pain and worsening stiffness vs a frozen shoulder gets stiffer then less painful. Patients with OA are also more likely to be elderly or have a history of shoulder trauma decades prior.
So how do you treat a frozen shoulder? It really depends on the phase
When the shoulder is in the early freezing phase its not really like winter, it’s like a summer heatwave – it’s hot and inflamed and it hurts!
Eventually summer ends – the inflammation and pain abates, and the shoulder is primarily stiff. It’s now frozen, it is winter – stiff and cold.
When a frozen shoulder is in its hot summer phase it is very easily irritated – it typically won’t like being exercised and may not like manual therapy such as massage. Or whatever you do, even if you get some temporary pain relief from treatments, it gets stiffer and sorer overall. If it’s identified early and a course of anti-inflammatory medication and/or a cortisone injection is given, it may halt the condition progressing to super sore and super stiff. Sometimes there is nothing you can do except let the freezing run its course and manage pain, especially night pain which can be brutal. This is where temporary use of stronger pain meds can be discussed with your GP.
Once winter has arrived, stiff phase frozen shoulder will start to tolerate being treated and will usually begin to respond to treatment – this may be in the form of manual therapy such as massage and joint mobilisation, a carefully prescribed stretching programme, and in some cases a hydrodilatation injection which involves a combination of local anesthetic, corticosteroid and saline injected into the shoulder joint attempt to stretch the tight joint capsule from the inside out. If a minimum of 25ml of saline can be injected, it’s more likely to be successful and needs following up with a prescribed stretching programme.
Treatment for frozen shoulders can be challenging – they key take away is to understand the phase the shoulder is. Is it summer or winter. In summer, tread carefully, be cool, be calm and think of anti-inflammatory approaches – don’t poke the bear! In winter – get moving, warm things up – understand progress will be slow but if there is no progress over a 6-week period, consider if intervention needs a boost.
Should you need an opinion or second opinion about your shoulder, please book in with one of our Senior Clinicians https://www.balance-health.com.au/bookonline