The adhesive capsulitis, popularly known as "frozen shoulder," is a picture which is characterized by limitation of movement and intense shoulder pain, which can last from several months to years. The adhesive capsulitis is caused by an inflammation of the capsule that covers the shoulder joint.
The frozen shoulder is a relatively common problem affecting about 3 to 5% of the general population. The disease becomes more frequent from the age of 55, being rare before 40 years of age. Women are more affected than men.
Studies show that the non-dominant arm shoulder is slightly more susceptible to adhesive capsulitis; Therefore, lefties have more risk of injury to the right shoulder and right-handers are more likely to have capsulitis left shoulder. Regardless of which shoulder is affected first by about 10% of the patients, the contralateral shoulder also becomes ill within a range of 5 years.
In this article we will explain what is adhesive capsulitis, as it arises, what are its symptoms and what are the forms of treatment currently available.
The shoulder joint formed by three bones: the humerus (upper arm bone), the clavicle and the spatula (also known as the scapula).
See the illustration to better understand the shoulder anatomy. The upper end of the humerus, called the humeral head has the shape of a globe and fits into the glenoid cavity, which is a spherical cavity in the side of the scapula. The fitting convex with a bone end in a concave cavity creates a hinge allowing the bone to move multiaxial form, enabling in a wide range of motion.
The shoulder joint is enclosed by the shoulder joint capsule, which is a membrane at the same time creates stability and allows free movement of the joint.
The adhesive capsulitis is a disease that causes inflammation, fibrosis, thickening and stiffness of the joint capsule, leading to pain and functional impotence of the shoulder. The capsule, which is normally an elastic fabric becomes rigid and quite painful.
The adhesive capsulitis is a different shoulder injury bursitis and tendinitis of the shoulder. The shoulder bursitis is caused by inflammation of the synovial bursa, which is a kind of cushion located inside the joint. Already tendinitis of the shoulder, as the name implies, is an inflammation of the shoulder tendons.
The adhesive capsulitis may be related to shoulder trauma or systemic diseases that have nothing to do the shoulder joint, such as diabetes, hypothyroidism and cardiovascular disease. The frozen shoulder can also be an idiopathic disease, that is, a problem that arises without being able to identify a clear cause.
We do not know exactly what the pathophysiological mechanism leading to the formation of adhesive capsulitis, but some risk factors are already well established. Are they:
The two main symptoms of frozen shoulder are pain and functional disability, which is the difficulty of making the usual shoulder movement.
The adhesive capsulitis usually takes place in three phases:
Painful or inflammatory phase - the adhesive capsulitis frame begins with progressive pain on movement, which becomes very intense and also causes gradual loss of the ability to move the shoulder. Symptoms worsen over weeks and usually worse at night. Unlike the bursitis and tendinitis, whose pain are associated with certain movements of the shoulder capsulitis pain arises in any kind of movement. This phase lasts from 2 to 9 months.
Phase freezing or stiffness - After months of agony, the pain starts to reduce. On the other hand, the shoulder stiffness becomes more intense, preventing their mobility. At this stage, which lasts from 4 to 12 months, functional disability is not directly linked to the pain, the patient can not simply move the shoulder as before because it is hard or "frozen". Lift the arm, scratching the back, wear a jacket or close the bra can become impossible tasks. At this stage, the pain usually only arise when the patient tries to move the shoulder beyond the possible.
Recovery phase or thawing - after more than one year of pain and disability, the shoulder starts to "unfreeze". The patient will gradually regaining the ability to move his shoulders broadly and the pain disappears completely. This phase can take 5 to 24 months for completion.
The time course of the disease varies from case to case, but it is very common for frozen shoulder disrupt the normal activities of the patient's life for at least 2 years. Some patients may become sequelae, permanently losing about 15% of the shoulder mobility.
The diagnosis of frozen shoulder is usually done by an orthopedist, by physical examination and laboratory tests.
A test that can be used to distinguish the other adhesive capsulitis of the shoulder pain disorders is the injection test. The doctor injects an amount of anesthetic into the joint and note if the patient can return to move the shoulder normally. In patients with frozen shoulder, anesthesia relieves pain, but not improves mobility.
X-rays and ultrasound are not good tests for the diagnosis of adhesive capsulitis, but they help in the differential diagnosis, it can identify other causes of pain in the shoulder as bursitis and tendonitis.
If after the physical examination, injection test and imaging tests, the doctor still in doubt about the diagnosis, MRI is the most appropriate test to assess the health of the joint capsule. In inciais stages of the disease, however, the resonance can not identify the capsulitis.
As adhesive capsulitis is a self-limited disease that resolves by itself after several months, the treatment initially aimed at the control of pain and restoration of part of the shoulder movements.
1 - Treatment of painful phase of the adhesive capsulitis
The pain may be initially treated with common painkillers such as paracetamol or dipyrone (metamizol). Anti-inflammatory drugs are drugs with good efficacy, but its daily use for several months at a time should be discouraged due to gastric, renal and cardiovascular side effects. In cases of difficult to control pain, the doctor may prescribe stronger painkillers, based on morphine derivatives.
The intra-articular corticosteroid injection (infiltration) is a good option for pain control in the first months, especially for those patients who do not improve with the use of analgesics or anti-inflammatory daily. Corticosteroids by mouth are not indicated by the high risk of side effects.
2 - Treatment of rigidity phase of the adhesive capsulitis
After the relief of pain, the doctor may indicate exercises and physical therapy to improve mobility of the affected shoulder. The exercises should be started lightly, always using pain as a parameter.
3 - Surgical treatment of adhesive capsulitis
Surgical treatment usually done by arthroscopy usually be restricted to only the most serious cases and they do not get satisfactory response to other types of treatment. The goal of surgery is to "unlock" the capsule, allowing the joint to move freely again. In general, surgery is performed only after 1 year of disease at a stage when there is less inflammation and fibrosis over the capsule.
