Shoulder Pain and History Taking
Shoulder pain is a common symptom of diverse causes. The pain may originate in the acromioclavicular (AC) or glenohumeral (GH) joint, in periarticular structures, or it may be referred from the cervical spine, brachial plexus, thoracic outlet, or infradiaphragmatic structures. Important points in the history include age, hand dominance, occupational and sport activities involving heavy lifting or overhead repetitive movements, history of trauma, onset, location, character, duration, radiation of the shoulder pain, aggravating and relieving factors, presence of night pain, and the effect on shoulder function.
Common Disorders of the Shoulder
Rotator Cuff Pathology
The spectrum of rotator cuff pathology ranges from mild rotator cuff tendinopathy to partial and complete rotator cuff tears. If the tear increases in size, a massive rotator cuff tear (< 5 cm) may develop. This can lead to the proximal migration of the humeral head and secondary GH osteoarthritis (cuff tear arthropathy).
Causative factors include repetitive low-grade trauma or unaccustomed activities, excessive overhead use in sport or work, lack of conditioning, aging, and compromise of the rotator cuff space by osteophytes on the undersurface of the AC joint, type 2 or 3 acromion (acromial-types) , or an os acromiale (unfused acromial epiphysis).
Bicipital tendinitis often results from chronic subacromial impingement occurring in association with rotator cuff tendinitis and rotator cuff tears. Primary isolated bicipital tendinitis is rare and develops as an overuse injury resulting from repetitive stresses applied to the tendon in certain sports, such as weight lifting and ball throwing. Anterior shoulder pain that is increased by overhead activities, shoulder extension, and elbow flexion is the main symptom. There is localized tenderness over the tendon in the bicipital groove, the Yergeson sign is present, and the speed test is often positive. Passive extension of the shoulder or resisted flexion of the elbow may also reproduce the pain. Signs of chronic impingement and GH instability are often present. Rupture of the long biceps tendon is associated with a positive Popeye sign.
Adhesive capsulitis, also known as frozen shoulder, is characterized by progressive global restriction of shoulder movements and is associated with pain and functional disability. A period of immobility of the shoulder is the most common predisposing factor. The capsulitis may be secondary to shoulder trauma, rotator cuff tendinitis or tears, bicipital tendinitis, or GH arthritis, or it may coexist with diabetes mellitus, hypothyroidism, or cerebrovascular events. An initial synovitis phase is followed by fibrous thickening and contracture of the capsular folds, axillary recess, rotator cuff interval, and coracohumeral ligament.
Acute shoulder instability usually results from a traumatic event such as a fall, sports injury, or motor vehicle collision. More than 90% of all acute shoulder instability is anterior.
Most cases of recurrent shoulder instability develop following an initial traumatic shoulder dislocation. A Bankart lesion, a traumatic avulsion of the anterior inferior glenoid labrum, is the essential lesion in this disorder.
Arthritis of the Shoulder
Both inflammatory arthritis, such as rheumatoid arthritis, and degenerative arthritis, such as osteoarthritis, can affect the shoulder joints. Inflammatory arthritis may involve the AC, GH, or SC joint, and the patient may experience swelling and tenderness of the affected joints. The shoulder is painful with limited range of motion in all direction. Other synovial joints in the body are often affected, and treatment is generally directed toward the systemic condition.
Thoracic outlet syndrome is often caused by compression of the lower brachial plexus and subclavian artery between the scalene muscles or by a cervical rib. It is associated with shoulder pain, which often radiates distally along the ulnar border of the forearm and hand. Pallor, coldness, and numbness, commonly of the ring and little fingers, may occur. The Adson maneuver is often positive: the ipsilateral radial pulse disappears when the patient abducts, extends, and externally rotates the shoulder while taking a deep breath with the head rotated maximally toward the affected side.
Acute brachial plexus neuritis (acute brachial plexitis or brachial neuralgic amyotrophy) is an uncommon disorder characterized by a rapid onset of burning pain in the shoulder and upper arm, followed a few days later by profound upper-arm weakness affecting multiple muscles supplied by the upper brachial plexus: supraspinatus, infraspinatus, deltoid, and sometimes biceps. Diagnostic studies include electromyography (EMG) and MRI. The course of the neuritis is usually one of gradual recovery in 3 to 4 months.
Suprascapular nerve entrapment syndrome is characterized by deep aching pain in the upper posterior aspect of the scapula, made worse by shoulder adduction, and by weakness of abduction and external rotation. It is caused by compression of the suprascapular nerve in the suprascapular notch. It can also result from repetitive trauma due to excessive overhead movements.
Cervical radiculopathy: caused by a cervical disk lesion, is associated with pain in the shoulder, radicular sensory symptoms, motor weakness, and reflex changes. Radicular pain and/or paresthesia may be reproduced by the Spurling Test and the upper extremity root extension test. Diagnostic studies include cervical spine radiography, MRI, and nerve conduction studies.