What is frozen shoulder?
Frozen shoulder is a condition in which there is significant loss of motion of shoulder joint accompanied by pain and stiffness. The movement involving reaching straight up and rotation of joint such as while reaching behind the back may be affected first although with time all movements may get affected. Pain may be deep seated, poorly localised and constant or only at night when lying on the affected side.
To understand the condition better it is helpful to know about the basic anatomy of shoulder joint. The shoulder joint is formed by three bones – the arm bone (humerus), shoulder blade (scapula), and the collar bone (clavicle). The rounded head of the arm bone (humerus) is relatively large compared to the socket of the shoulder blade and this size discrepancy allows for the large range of motion of the shoulder. The shoulder joint is surrounded by the strong joint capsule and further supported by a group of muscles called the rotator cuff.
In frozen shoulder the capsule surrounding the shoulder joint becomes thickened and tight thereby limiting the movements of the joint. The joint may loose some of its lubricating fluid reducing the space for the arm bone ot move. Movement of shoulder causes pain, hence one tries to avoid this which leads to further contraction of the capsule. As the condition advances scarring or adhesions may develop between the capsule and the head of arm bone further limitating the movement. With time there may be relative weakening of the muscles with loss of muscle mass (atrophy).
What causes frozen shoulder?
The cause behind the condition is not well understood. This condition is estimated to affect 2-3 % of individuals although this may be an overestimation as previously many more conditions were labelled as frozen shoulder – with it becoming more like a waste bin diagnosis. The actual incidence may be around 0.75%.
It is seen more commonly in
- Women as compared to men
- People over the age of 40 years, most commonly between the age of 40-60 years
- Diabetics have approximately five times more chances of developing this condition compared to non – diabetics. (10 – 20 percent of individuals with diabetes may develop frozen shoulder and about 30% of people with a frozen shoulder also have diabetes).
- Periods of shoulder immobilization like after a fracture or stroke (more like an under use injury)
- Patients with overactive or underactive thyroid
- Parkinson’s disease
How is frozen shoulder diagnosed?
Frozen shoulder is diagnosed clinically, however investigations are required to rule out other conditions which may present similar symptoms.
To diagnose frozen shoulder, your doctor will:
- Take detailed history of your condition and look for any predisposing factors
- Conduct a physical examination of your shoulders, arms and neck:
- The doctor will evaluate the range of shoulder movement. In frozen shoulder both the active movements (when you move your shoulder/ arm) and passive movements (when the doctor moves your shoulder /arm) are reduced. Examination may reveal tenderness in the front of shoulder at a specific spot called the coracoid process.
- The doctor may carry out other special tests to rule out other conditions which may present with similar symptoms
- He may conduct examination of your neck as neck problem manifests with shoulder pain frequently
- Investigations- X-rays of the shoulder may be requested to rule out arthritis, MRI scan and ultrasound may be requested to rule out other problems such as a rotator cuff tear. Ultrasound scan can show thickening of coracohumeral ligament or the capsule
- Blood tests may be requested to check for diabetes / thyroid problems
Can a frozen shoulder recover on its own?
A significant number of cases improve with simple exercises and pain control, however, it can take a long time too and sometimes as long as 3 years. The limitaion of daily activities can have significant impact on the quality of life. It is often self-limited, however, some patients never regain full function of their shoulder.
Typically the condition is described to pass through three stages
This is the initial stage where the pain and restriction of movement develops. Intitially pain may be only on movement or at night when lying on the affected side. Slowly, it can increase in severity, affecting the shoulder joint diffusely and often spreading towards the upper arm. This stage can last from 6 to 9 months.
In this stage the pain may become better although the restriction of movement persists and may become worse. This stage can last 4-12 months.
During this phase, the movements start to return slowly and it can last 6 months to 2 years.
What is the treatment for frozen shoulder?
The treatment for a frozen shoulder is focused on relieving pain and restoring the shoulder’s normal range of motion. Timely interventions can help control pain and restore function sooner. A pain clinic can play a significant role by prescribing medications, using timely interventions such as injections and providing supervised physiotherapy. This Multi discliplinary approach has the best chances of improving outcomes and reducing disability.
Treatment options are explained below and it is important to understand that they are to be used in tandem and not seen as alternatives to each other.
- MEDICATIONS– anti-inflammatory drugs can help reduce the pain and inflammation, although these should not be used without the advice from your doctor. Your pain specialist may consider other stronger medications depending on your pain severity and other medical comorbidities.
- INTERVENTIONS– This may include a shoulder joint steroid injection or hydrodistension of the shoulder joint. These injections can help reduce pain and improve range of movement, reducing disability.
Shoulder joint steroid injections- Steroid injections injected directly into the joint are preferred over the oral steroid as they are associated with fewer side effects. Some studies have found that oral steroids are as much as 5 times more likely to give you the typical steroid side effects when compared to the one with off joint injections. Also the lack of long-term benefits makes oral steroids a less attractive option in this condition. Some studies comparing physiotherapy with steroid injections have found no significant difference in pain relief or shoulder function whereas others have found improved shoulder function with steroid injections.
Hydrodistension of the joint involves injecting sterile water or local anaesthetic into the shoulder joint with the intention of stretching the joint capsule to improve range of motion. There is evidence supporting the use of a combination of hydrodilatation and corticosteroid injection, as it may expedite recovery of pain free range of motion compared to corticosteroid injection alone.
Both these procedures can be performed in OPD settings under ultrasound guidance. Ultrasound helps to improve accuracy, maximising the changes of getting benefit from injections.
- Physical therapy. This forms an essential component of frozen shoulder treatment and requires regular active participation of the affected individual. The aim of physical therapy is to maintain, improve range of motion and help in strengthening of the joint, Physiotherapy and corticosteroid injections combined may provide greater improvement than physiotherapy alone.
- Surgery. This is rarely necessary to treat frozen shoulder. It is considered when there is minimal improvement after 6 to 12 weeks of nonsurgical treatment. Options include manipulation under anaesthesia and arthroscopic capsule release. Shoulder manipulation involves forcefully moving the shoulder under general anesthesia to loosen up your shoulder tissue and disrupt the adhesions. This needs to be supported by physiotherapy after the procedure. Arthroscopic capsular release is considered in some cases when other treatments have failed to provide relief.