Shoulder pain is defined as chronic when it has been present for longer than six months. Common conditions that can result in chronic shoulder pain include rotator cuff disorders, adhesive capsulitis, shoulder instability, and shoulder arthritis. Rotator cuff disorders include tendinopathy, partial tears, and complete tears.
Chronic shoulder pain is relatively common and can result from a number of pathologies including rotator cuff disorders, adhesive capsulitis, shoulder instability, and shoulder arthritis. First line treatments include a rehabilitative approach with focus on exercise, offered in conjunction with oral analgesia. In some patients injection treatments may be needed if conservative measures prove to be ineffective. Suprascapular nerve block and suprascapular nerve ablation techniques can be used for sustained pain relief in patients who fail to make progress with simpler treatments.
At Pain Spa Dr Krishna is very experienced in interventional treatments. Dr Krishna always performs shoulder injections and suprascapular nerve block under ultrasound guidance for greater accuracy and improved safety. Ultrasound gives the added advantage of visualizing the surrounding tendons and muscles, which can be contributory to pain.
A clinical decision rule that is helpful in the diagnosis of rotator cuff tears includes pain with overhead activity, weakness on empty can and external rotation tests, and a positive impingement sign. Adhesive capsulitis can be associated with diabetes and thyroid disorders. Clinical presentation includes diffuse shoulder pain with restricted passive range of motion on examination. Acromioclavicular osteoarthritis presents with superior shoulder pain, acromioclavicular joint tenderness, and a painful cross-body adduction test. In patients who are older than 50 years, glenohumeral osteoarthritis usually presents as gradual pain and loss of motion. In patients younger than 40 years, glenohumeral instability generally presents with a history of dislocation or subluxation events.
Shoulder pain is responsible for approximately 16 percent of all musculoskeletal complaints, with a yearly incidence of 15 new episodes per 1,000 patients seen in the primary care setting.
Acromioclavicular joint pathology is usually well localized. A history of an injury to the joint (shoulder separation), heavy weight lifting, tenderness to palpation at the acromioclavicular joint, pain with cross-body adduction testing, extreme internal rotation, and forward flexion are consistent with the diagnosis. Radiographs may be difficult to interpret because most patients have acromioclavicular osteoarthritis by the age of 40 to 50 years. A distal clavicle lysis or an elevated distal clavicle supports the diagnosis, whereas the absence of tenderness to palpation at the acromioclavicular joint is inconsistent with the diagnosis.
Adhesive capsulitis refers to a painful shoulder in which the active and passive ranges of motion are severely limited. Gradual onset of pain and stiffness, loss of motion in all planes with increased pain at the extremes of motion, and a history of diabetes or thyroid disease are consistent with the diagnosis. Radiographs are typically negative, and osteoarthritis on radiography is inconsistent with the diagnosis. A normal range of motion is antithetic to the diagnosis.
Glenohumeral instability refers to disorders affecting the capsulolabral complex, including dislocation and subluxation. The patients are usually younger than 40 years and have a history of dislocation or subluxation events, which is often involved with collision or overhead sports. A “dead arm,” numbness over the lateral deltoid, and a positive apprehension test are consistent with the diagnosis. Examination findings inconsistent with the diagnosis are no history of dislocation or subluxation and a negative apprehension test. Positive radiographs are helpful for diagnosing Hill-Sachs lesion, dislocation, and inferior glenoid avulsion fracture, but are non-diagnostic if negative.
Glenohumeral osteoarthritis usually presents as gradual pain and loss of motion in patients older than 50 years. A history of arthritis, previous shoulder surgery, pain, crepitus, and decreased motion is consistent with the diagnosis. Radiographs are diagnostic. Normal radiographs and a normal range of motion are inconsistent with the diagnosis.
Rotator cuff disorders that affect the function of the rotator cuff include a partial or complete tear, tendinitis or tendinosis, and calcific tendinitis. Initially, it is more important to differentiate this group of disorders from the other groups than it is to identify the specific diagnosis. Typically, the patients are older than 40 years and complain of pain in the lateral aspect of the arm with radiation no farther than the elbow. Weakness, a painful arc of motion, night pain, and a positive impingement sign are components of the history and physical examination that are consistent with this diagnosis. Findings that are inconsistent with this diagnosis include being younger than 30 years, having no weakness, and presenting no impingement signs. Positive radiographs can be helpful to diagnose calcific tendinitis, acromial spur, humeral head cysts, or superior migration of the humeral head, but are typically normal.
Numerous other problems that can affect the shoulder are somewhat less common, such as biceps and labral pathology (e.g., SLAP tear—superior labrum anterior to posterior tear—an avulsion injury to the root of the long head of the biceps tendon) and multidirectional instability. Other conditions are extremely uncommon, such as a suprascapular nerve injury, Parsonage Turner syndrome (brachial plexus neuritis), and a neuropathic shoulder from syringomyelia. The shoulder can also be the area of perceived pain for many non-shoulder problems, including fibromyalgia, cervical radiculopathy, and thoracic outlet syndrome. Fibromyalgia is notable for classic areas of tender points. Cervical radiculopathy pain is generally posterior, with radiation to the neck and down the arm below the elbow. Thoracic outlet syndrome, like cervical radiculopathy, is notable for symptoms that extend past the elbow and often into the hand. There can be neurologic or vascular symptoms based on the subtype. Positive radiographs are helpful for diagnosing severe cervical osteoarthritis, but are typically negative. Positive provocative shoulder testing (e.g., Hawkins’ impingement test, empty-can test, external rotation test) that disappears after a subacromial lidocaine injection is inconsistent with the diagnosis of fibromyalgia, cervical radiculopathy, or thoracic outlet syndrome.
A recent Cochrane review showed little evidence for or against the most common treatments of these chronic shoulder disorders; this is mainly because of a lack of well-designed clinical trials. Nonetheless, most patients with a chronic shoulder disorder can initially be treated conservatively with some combination of activity modification, physical therapy, medications, and corticosteroid injections, if necessary.
Activity modification is a simple treatment for reducing shoulder pain with specific recommendations based upon the underlying diagnosis. Reduction or avoidance of overhead activity is the mainstay of treatment for rotator cuff pathology, glenohumeral osteoarthritis, and adhesive capsulitis, because this avoids the painful arc between 60 to 120 degrees, which is a provocative maneuver for the diagnosis of these disorders. Avoiding heavy loading of the shoulder can also help with the pain associated with glenohumeral osteoarthritis. Certain overhead activities can precipitate instability symptoms. Bench pressing, kayaking, and overhand throwing are particularly risky in patients with an unstable shoulder. Cross-body shoulder adduction, such as the motion performed in the golf swing or while weight lifting, should be limited in patients with acromioclavicular osteoarthritis because it can recreate acromioclavicular joint pain.
Pain control is imperative to allow for the progression of treatment. The use of nonsteroidal anti-inflammatory drugs (NSAIDs), Paracetamol, or short-term opiate medication may help achieve this goal. There is no conclusive support for the use of NSAIDs over simple analgesia in the treatment of chronic shoulder pain. Therefore, the risks and benefits of each class should be considered before use.
Physical therapy encompasses a large range of treatments. There are therapeutic modalities designed to alleviate pain directly (heat and ice, ultrasound), and stretching and strengthening exercises intended to relieve pain by improving overall shoulder function. The type and focus of physical therapy depends on the underlying etiology. Little evidence exists for the use of therapeutic modalities alone. A recent Cochrane review showed that stretching and strengthening provide improved short-term recovery and long-term function in patients with rotator cuff disease. The success of physical therapy is optimized when the underlying diagnosis is known and the patient actively participates in the rehabilitation process on a daily basis.
If patients have a poor response to initial treatment for chronic shoulder disorders, corticosteroid injections combined with a local anesthetic can be administered. The injection needs to be directed toward the affected area, such as the subacromial space, acromioclavicular joint, or glenohumeral joint. The role of subacromial injection for rotator cuff disease is an area of active research and controversy. Two systematic reviews found little evidence to support or refute the use of subacromial injection; two systematic reviews found it to be beneficial for rotator cuff tendinitis and shoulder pain; and another review suggested a possible small benefit. Individual studies have found subacromial injections to be beneficial, particularly for short-term decreases in pain and increases in function.
Patients with adhesive capsulitis have been shown to respond to intra-articular injections with decreased pain and increased function, particularly in combination with physical therapy for stretching.
Intra-articular hyaluronic acid injections have shown promise in several studies on glenohumeral osteoarthritis.
Injection into the acromioclavicular joint can provide some diagnostic information because even short-term relief of symptoms can help confirm the diagnosis.
Several recent studies have questioned the accuracy of injections performed blindly and hence these injections are best performed under ultrasound or fluoroscopic guidance.
The suprascapular nerve block has been utilized for a number of years to address various causes of shoulder pain. Early advocates of the Suprascapular nerve block reported its usefulness in treating shoulder pain secondary to rotator cuff degenerative tears. Subsequent studies expanded its indications to include conditions such as glenohumeral degenerative joint disease, adhesive capsulitis, and postoperative shoulder pain following arthroscopic surgery.
The procedure is done on an outpatient basis. The procedure is performed under ultrasound guidance to ensure accuracy of needle placement. Patients need to be aware that the outcome of the procedure is variable and they may not receive the desired benefits. Similarly, they must be aware of the transient nature of the therapeutic benefits and that there may need repeated injections.
Patients who get temporary relief from suprascapular nerve block may be suitable for suprascapular nerve ablation (pulsed radiofrequency treatment). This is likely to provide longer-term pain relief.