Definition
Adhesive capsulitis, commonly termed frozen shoulder, is a condition causing strong pain and rigidity of the shoulder joint. Adhesive capsulitis can manifest as an acute pathology and/or progress to a chronic stage.
Pathology
Adhesive capsulitis is caused by chronic inflammation and thickening of the shoulder capsule with the formation of adhesions that render the shoulder rigid and painful. With the reduction of the capsule volume the movement of the shoulder is heavily reduced. When arising from a traumatic injury, adhesive capsulitis can be associated with bone fractures, lesion to the capsule, tendon damage and scar formation. The condition can also develop due to excessive scar formation post-surgery to the shoulder. The exact pathophysiology remains unclear.
Classification
A frozen shoulder normally progresses slowly. Three stages of the diseases have been identified, each one lasting several months:
Freezing or Painful Stage This is the most painful phase that consequently restricts the movement of the shoulder. It can last between 6 and 12 weeks.
Frozen Stage Although the pain is reduced in this phase, it is associated with worsening of shoulder stiffness. The duration varies between 4 and 6 months.
Thawing Stage During this stage, the mobility of the shoulder gradually improves. It takes up to over a year to restore shoulder mobility. 10-15% of the patients suffer from persisting stiffness and the shoulder never returns to normal function.
Causes
The causes leading to a frozen shoulder have not been fully elucidated. The pathology may be unrelated to specific diseases or injuries but is frequently observed after trauma and post-surgery to the shoulder or arm. A frozen shoulder is mostly the consequence of prolonged immobilisation due to the use of a sling or following a continued period of ongoing shoulder pain. It can also be caused by an incorrect posture during work or sport activities.
Risk factors
Frozen shoulder does not correlate with specific professions or sports but is mostly linked to ageing in individuals between 40 and 60 years of age. In women it is twice as frequent than in men. It has been associated with chronic diseases including diabetes type 2 (up to 40% incidence), cardiovascular diseases, hyper and hypothyroidism as well as stroke and Parkinson's disease.
Symptoms
Pain is the main symptom of a frozen shoulder being usually an aching pain of the shoulder area occasionally extending to the upper arm. Pain is significantly stronger at the initial stage of the condition. Other symptoms include: Pain when lying on the shoulder Difficulty in performing normal daily activities (brushing hair, putting on shirts or bras).
Diagnosis
The clinical examination for the diagnosis of a frozen shoulder begins with medical history and physical investigation using a variety of tests to assess changes in the range of movement. X-rays are taken to exclude the presence of other diseases (arthritis). Ultrasound and MRI are performed to visualise the pathological changes of the soft tissue structures of the shoulder joint. Subacromial bursitis is a pathology possibly associated with a frozen shoulder.
Treatment
Nonoperative Treatment
Conservative treatment of a frozen shoulder includes measures to reduce pain and inflammation with the application of ice and heat packs and administration of oral anti-inflammatory medications (NSAIDs) or local steroid injection with guidance via ultrasound. Hydrodilatation (or hydrodilation) consists in the injection of cortisone to suppress inflammation. Then, the joint capsule is stretched using the infusion of a saline solution (20-40 ml). This procedure aims at tearing the scar tissue formed around the capsule during the pathological process and thus improve mobility. The success may vary. Physiotherapy is another approach of conservative treatment beginning as early as possible to restore mobility of the frozen shoulder. It includes stretching and exercise with passive and active movements.
Surgical treatment
If symptoms are not improving with conservative treatment and rehabilitation, in rare cases surgery is recommended. This includes a robust manipulation of the shoulder under anaesthesia, whereby force is used to release the stiffness and restore flexibility of the joint. This does not require a surgical access to the shoulder. Shoulder arthroscopy, a minimally invasive procedure compared to open surgery, aims to dislodge the scarred tissue surrounding the capsule and remove the adhesions that impair movement. Often both methods are combined to obtain optimal results.
Rehabilitation
Following surgery, physiotherapy is required to maintain the range of movement that was achieved with the intervention. The rehabilitation regime includes a variety of approaches:
Massage
Electrotherapy
Dry needling
Hydrotherapy
Acupuncture
Hydrodilatation
Gentle exercise to restore joint flexibility and muscle strength to the shoulder
Correction on modifying posture and sport activities
The time of recovery can last from several weeks to months. During this period physiotherapy is essential. Most patients have a satisfactory level of recovery, however for some, pain and residual shoulder stiffness may remain.
Prevention
Frozen shoulder usually does not reoccur but a few cases of recidivism have been reported. It is paramount that any form of shoulder or arm immobilisation is avoided or reduced to a minimum to prevent the onset of a frozen shoulder. This applies particularly after trauma and following surgery to the upper extremities. To facilitate the maintenance of shoulder movements anti-inflammatory therapy is advised. Occasionally, at initial symptoms shoulder mobility is restored with early manipulation under anaesthesia.