Soft-Tissue Rheumatic Conditions
SHOULDER
Rotator Cuff Disorders
The rotator cuff is composed of four muscles: the subscapularis anteriorly (internal rotator), supraspinatus superiorly (elevator), and the infraspinatus and teres minor posteriorly (external rotators). Together they provide dynamic stability to the shoulder joint (Fig. 1).
Figure 1 Ligamentous and musculotendinous attachments about the shoulder joint.
From Hochberg MC, Silman Aj, Smolen JS et al (eds): Practical Rheumatology, 3rd ed. Philadelphia: Mosby, 2004.
Although pain is the most common symptom of rotator cuff disorders, patients might also complain of weakness and loss of motion. The pain is usually localized to the lateral arm and shoulder and can awaken the patient during the night. Pain is worsened with overhead activities such as using a hair dryer and combing hair. Painful weakness, atrophy, and inability to abduct and elevate the arm are seen in more advanced conditions.1
The age of the patient can also provide clinical clues to the diagnosis. Underlying instability is more likely in a younger patient, and a mechanical or degenerative cause is more likely in an older patient (Table 1).
On physical examination, there is tenderness to palpation of the proximal humerus at the insertion site of the rotator cuff. Tenderness of the shoulder anteriorly suggests biceps tendinitis, whereas more lateral tenderness suggests supraspinatus tendinitis or subdeltoid bursitis. Passive ROM is greater than active ROM, with a painful arc between 60 and 120 degrees of abduction. The Neer and Hawkins impingement tests can be done to evaluate for rotator cuff disorders. With the Neer impingement test, the examiner forcibly flexes the patient’s arm forward with one hand while stabilizing the patient’s shoulder with the other hand. The Hawkins impingement test involves forward flexion of the shoulder to 90 degrees and internal rotation of the shoulder. Pain with these maneuvers suggests an impingement syndrome.2
Imaging of the shoulder is usually not necessary unless symptoms persist for more than 3 to 4 months despite conservative therapy. Other indications for imaging include features suggesting a need for surgery or if the diagnosis is in doubt. Findings on plain radiographs that can be associated with impingement include arthritic changes of the glenohumeral joint, subacromial space calcifications, acromial spurs, or decreased distance between the acromion and the humeral head. Arthrography was formerly the gold-standard imaging study for full-thickness rotator cuff tears, but it is now largely replaced by magnetic resonance imaging (MRI). The finding of a rotator cuff irregularity on imaging, however, does not necessarily imply causality of symptoms, because up to 26% of asymptomatic people have a rotator cuff tear on MRI.3
Rotator cuff tendinitis and subacromial bursitis are initially managed with a short period of rest (up to a week) and nonsteroidal anti-inflammatory drugs (NSAIDs). If this approach fails, a subacromial corticosteroid injection may be tried (Fig. 2 and Box 1). Once the pain is improved and normal shoulder movement has returned, a supervised therapy program should be instituted to strengthen the rotator cuff muscles and preserve range of motion. If symptoms persist despite an adequate trial of these measures, surgery may be indicated.
Figure 2 A and B, Posterolateral approach to the subacromial bursa.
From Hochberg MC, Silman Aj, Smolen JS et al (eds): Practical Rheumatology, 3rd ed. Philadelphia: Mosby, 2004.
