SHOULDER
Retractile capsulitis
Retractile capsulitis, also known as frozen shoulder, is a condition affecting the shoulder joint, characterized by pain and stiffness. It is a self-limiting condition that tends to improve over time.
Prevalence
It is twice as common in women, and most often affects people between the ages of 40 and 60, but can occur at any age. Its prevalence is estimated at between 2% and 5% of the general population. Although the condition can occur in both shoulders, it is generally unilateral, and more often affects the non-dominant arm.
Frozen shoulder: etiology, risk factors and disease stages
The etiology of frozen shoulder is not fully understood. However, several factors may contribute to the development of the disease. The primary form is idiopathic, meaning there is no clear cause. However, post-traumatic and post-surgical frozen shoulder can occur after any upper limb injury, fracture of the proximal humerus, rotator cuff repair or axillary dissection for malignancy. The pathophysiology of frozen shoulder involves an inflammatory process causing fibroblastic proliferation of the joint capsule, leading to thickening, fibrosis and adhesion of the capsule to itself and to the humerus. This leads to a mechanical blockage of movement, which can be disabling. Several associated diseases can increase the risk of developing frozen shoulder, including diabetes, autoimmune thyroid disease, Dupuytren’s disease, atherosclerosis and cervical disc disease. Diabetes, in particular, is associated with worse outcomes and an increased risk of frozen shoulder, especially in older patients.
Before any noticeable loss of movement, frozen shoulder presents with an insidious onset of general shoulder pain. The character and severity of the pain vary and depend on the stage of the disease. The three stages of the disease include the freezing stage (3 months), characterized by an insidious onset of pain at rest and with movement, as well as sleep disturbance. The frozen stage (6 months) is marked by a reduction in pain but significant limitation of movement, affecting activities of daily living. The thawing stage (9 months) is characterized by absence of pain and improved movement, although still below normal. Physical examination shows symmetrical loss of active and passive range of motion, with external rotation deficit the most common presentation.
Examination and treatment of retractile capsulitis
In addition to a thorough physical examination, a number of further tests may be used to diagnose frozen shoulder syndrome. Standard radiographs may show disuse osteopenia but are mainly obtained to assess other pathologies such as osteoarthritis, posterior dislocation or surgical hardware. Although MRI with or without arthrography is not necessary for diagnosis, it can be useful for evaluating other pathologies. MRI can show loss of the axillary recess, which is evidence of joint capsule contracture. In addition, a blood test with a metabolic panel and endocrine tests such as HbA1c and TSH can be obtained to assess underlying conditions such as diabetes or associated thyroid disorders.
Management of retractile capsulitis can be either conservative or operative. Conservative treatment options include physiotherapy, anti-inflammatory drugs, intra-articular corticosteroid injections, as well as heat and cryotherapy. These are often effective and considered first-line treatment. Physiotherapy programs should include gentle, pain-free stretching and be supervised, lasting 3 to 6 months. Passive mobilization should never be forced, to avoid re-inflaming the capsule, especially during the initial phase. Corticosteroid injections can be performed in 2 places: subacromial injection is preferred in the early stages of freezing, when pain is a major complaint, and targets inflammation in the rotator cuff tendons and bursa; intra-articular injection is preferred in later stages, when stiffness and limited range of motion become more important, and targets inflammation in the joint capsule. Suprascapular nerve block is also an option that can help reduce pain and decrease inflammation, as well as benefit more from physiotherapy.
Surgical options are indicated after conservative measures have failed. They include manipulation under anesthesia and arthroscopic or open capsular release. Manipulation under anaesthetic should be avoided during the freezing phase, and is contraindicated in diabetics due to a high failure rate, as well as after rotator cuff or labrum repair. These procedures carry the risk of complications, one of the most common being residual stiffness. Axillary nerve injury may occur with capsular release. Manipulation under anesthesia can lead to proximal humerus fractures, dislocation, rotator cuff tears or brachial plexopathy, particularly in patients with osteoporotic bone or those who undergo excessive manipulation. Complications common to other procedures may also occur, such as bleeding, infection and persistent pain. In addition, diabetic patients may have poorer outcomes regardless of treatment, and extra caution should be taken with this patient population.
After surgery, you’ll need to follow a rehabilitation program to restore strength and function to your shoulder. This will usually include physiotherapy exercises.
It’s important to note that treating retractile capsulitis can be a slow process, and healing can take several months or more.
