What is Frozen Shoulder?
Adhesive capsulitis, or frozen shoulder, refers to a gradual, painful condition of the shoulder that lasts for more than three months. This condition is an inflammation that leads to the thickening and tightening of the shoulder joint, resulting in slowly increasing stiffness and significant limitation in the shoulder’s movement, especially outward rotation. However, symptoms may appear suddenly and take a while to improve. Typically, most patients experience satisfactory recovery, although this can take two to three years.
What Causes Frozen Shoulder?
Frozen shoulder is a medical condition and the exact cause of it isn’t completely understood yet. However, there are several factors that may increase the risk of developing it:
- Diabetes mellitus: as much as 20% of people with diabetes can experience frozen shoulder
- Stroke: People who’ve had a stroke may develop this condition
- Thyroid disorder: Certain issues with your thyroid can make you more likely to get frozen shoulder
- Shoulder injury: An injury can cause inflammation and stiffness leading to frozen shoulder
- Dupuytren’s disease: This is a hand condition that can affect the connective tissue in your shoulder
- Parkinson’s disease: This nervous system disorder can affect physical movements, including in the shoulder
- Cancer: Certain types of cancer might increase the risk
- Complex regional pain syndrome: This is a form of chronic pain that typically affects an arm or a leg
These are just possible reasons why someone might get frozen shoulder and it’s important to remember that having these does not automatically mean you will develop it.
Risk Factors and Frequency for Frozen Shoulder
Adhesive capsulitis, also known as frozen shoulder, occurs in about 5% of the population. It is four times more common in women than in men, and it’s usually the non-dominant shoulder that’s affected.
Signs and Symptoms of Frozen Shoulder
Frozen shoulder is a condition that typically begins with sudden, one-sided shoulder pain. It can cause stiff, restricted movement of the shoulder. Initially, it affects the shoulder’s ability to rotate externally and later impacts the ability to lift the arm sideways. The condition can interfere with daily life, making it hard to reach overhead or to the side. This could make normal activities, like hanging clothes or fastening a seatbelt, difficult. It can also create challenges with hygiene, getting dressed, or brushing hair due to the limited shoulder rotation. Neck pain can also be a common issue as the neck muscles compensate for the lost shoulder movement.
Diagnosing frozen shoulder relies heavily on physical examinations, although this could be challenging due to the patient’s pain or stiffness. Two common examination methods are testing the patient’s ability to touch the shoulder blade from behind the neck and from behind the back. However, a key symptom of frozen shoulder is the loss of passive range of motion.
- Sudden shoulder pain
- Restriction in rotating shoulder externally
- Limited ability to lift arm
- Problems in reaching overhead or to the side
- Challenges with personal hygiene or getting dressed
- Neck pain
Though active motion tests can be skipped in cases where passive movement is significantly restricted, it’s important to consider a frozen shoulder diagnosis in patients who gradually lose range of motion during follow-ups. Patients with frozen shoulder usually show a significant restriction in active and passive range of motion, particularly when rotating the shoulder externally or lifting the arm. If every direction of motion is restricted, it could signal not just the presence of developed frozen shoulder but the potential for an underlying serious condition like cancer or a fracture.
Testing for Frozen Shoulder
Frozen shoulder is a medical condition that can be identified by examining your medical history, a physical check-up, and taking images of the shoulder to rule out other possible conditions. There is no specific lab or imaging test that can definitively diagnose a frozen shoulder alone.
Imaging the shoulder to diagnose a frozen shoulder can be tricky, as most common methods such as X-rays, ultrasound, MRI, and CT scans usually don’t show anything out of the ordinary. Therefore, these images are mainly used to ensure that the patient doesn’t have other shoulder conditions like tears in the rotator cuff tendons or arthritis in the shoulder joint. The most commonly used tool for examining shoulder conditions is musculoskeletal ultrasonography, a high-resolution imaging technique. However, there are still no specific ultrasound findings that can confirm the diagnosis of frozen shoulder.
Some researchers have suggested that a thickening of a ligament in the shoulder could be a characteristic of a frozen shoulder when observed in an ultrasound. There could also be an accumulation of fluid around the long head of the biceps tendon, although this could also be due to other shoulder conditions such as rotator cuff disorders or inflammation of the tendon of the biceps.
Furthermore, ultrasound is less useful in identifying conditions associated with instability or tears in the upper rim of the shoulder socket. While routine x-rays usually don’t provide much help in diagnosing frozen shoulder, they can be useful in ruling out other causes such as tumors or arthritis.
An MRI can show a thickening of the ligament and joint capsule in the shoulder, and an MRI scan after injecting a contrast dye might show a reduced amount of space in the shoulder joint.
There is a diagnostic test known as the “lidocaine test,” which involves injecting a local anesthetic into the space below the acromion, the outer end of the shoulder blade. This test can help to clarify the diagnosis in uncertain cases by ruling out conditions beneath the acromion. In patients with a frozen shoulder, their limited range of movement usually stays the same after an injection into this space. However, in patients with conditions affecting the area below the acromion, such as a problem with the rotator cuff or bursa, their range of movement commonly improves after the injection. The injection can easily be done with the help of an ultrasound for guidance.
Treatment Options for Frozen Shoulder
While there are many articles on Adhesive Capsulitis (AC), also known as “frozen shoulder,” no consistent agreement exists on its management. Most treatment options for AC are non-surgical and may include medication and physical therapy.
In the early stage, AC is often treated as subacromial pathology (disorders that impact the subacromial space in the shoulder). At this point, the shoulder is typically undergoing a “freezing” process and is largely inflamed. However, as the condition progresses, the inflammation lessens while restriction in the shoulder’s range of motion (ROM) becomes more prominent and the pain related to inflammation becomes less pronounced. Because of these differences, treatment should be based on the stage of the disease. Correctly identifying the stage of the condition can help devise more specific treatment plans. With early AC, the focus of treatment should be on managing pain, reducing inflammation, and educating the patient.
Initial treatment for adhesive capsulitis may include common pain relievers like acetaminophen or NSAIDs (nonsteroidal anti-inflammatory drugs). Although evidence about the effectiveness of NSAIDs in treating frozen shoulder is limited, these medications can be used for short-term relief from the night pain, if it presents. However, if the pain is severe, stronger painkillers like opioid analgesics may be necessary.
Physical therapy plays a crucial role in managing pain and restoring normal shoulder movement. This involves manual therapies such as soft tissue mobilization and gentle stretching. Various therapeutic techniques like therapeutic ultrasound, cryotherapy (use of extreme cold in therapy), or transcutaneous electrical nerve stimulation (TENS) – a method used to relieve pain – might be used. During this stage, the patient should also engage in therapeutic exercise to prevent further limitation of the shoulder’s range of motion. Patients should also continue these exercises at home. If shoulder pain is moderate to severe and hasn’t responded to non-surgical treatments, corticosteroid injection into the shoulder joint may be considered under ultrasound or fluoroscopy guidance (to ensure correct placement of the needle). Rehabilitation exercises should be continued after the injection.
As the AC progresses to the “frozen” and then the “thawing” stages — when the shoulder begins to regain its movement — the goal of treatment shifts to overcoming the range of motion limitation. More intensive mobilization exercises are required at this stage. If the condition has not significantly improved after six months of non-surgical treatment, more aggressive treatments may be considered. These might include capsular hydrodilatation (stretching the joint capsule by injecting it with saline), manipulation under anesthesia (forcibly moving the shoulder to tear the contracted capsule), or arthroscopic capsular release (surgery to free up the shoulder joint), particularly in the rotator interval (a part of the shoulder joint).
What else can Frozen Shoulder be?
Adhesive capsulitis, especially during its early stages, can be difficult to diagnose because it shares symptoms with other shoulder conditions such as subacromial pathology and rotator cuff tendinopathy. This similar presentation can cause delays in correctly identifying adhesive capsulitis. With other shoulder issues, patients usually report pain and a restriction in their range of motion, often as a result of lifting heavy objects or making repetitive movements overhead. On the other hand, adhesive capsulitis typically starts without a clear reason or with a history of overuse. Extra attention should be given if there is a history of cancer.
Some conditions that may appear like early-stage adhesive capsulitis include:
- Subacromial pathology and rotator cuff tendinopathy
- Post-stroke shoulder subluxation
- Referred pain from the neck or from a cancer, such as a Pancoast tumor
As adhesive capsulitis progresses, it’s marked by a severe limitation of motion, making the diagnosis clearer. However, it’s also important to rule out shoulder arthritis, which can be dismissed if the patient’s shoulder movement improves after having a lidocaine injection in their joint.
Lastly, the patient’s age can also give some insight. It’s unusual to see frozen shoulder in those younger than 40 years old. Instead, those who are 70 years or older are more likely to have tears in their rotator cuff or osteoarthritis in their shoulder joint.
What to expect with Frozen Shoulder
The typical duration of adhesive capsulitis, also known as frozen shoulder, is between 1 to 3.5 years, with the average being about 30 months. In approximately 15% of patients, the other shoulder can also be affected within a period of 5 years.
Possible Complications When Diagnosed with Frozen Shoulder
- Continuing pain
- Remaining stiffness
- Breaking of the upper arm bone
- Tearing of the bicep tendon after shoulder manipulation
