A: Acromioclavicular joint degeneration
Diagnose acromioclavicular joint degeneration.
This patient's presentation is most consistent with acromioclavicular joint degeneration. Acromioclavicular joint degeneration typically presents with pain located on the superior aspect of the shoulder, although pain may be poorly localized in some patients. On examination, there may be tenderness to palpation of the acromioclavicular joint as well as pain with arm adduction across the body (cross-arm test) and with shoulder abduction beyond 120 degrees. Plain radiographs can reveal degenerative changes of the acromioclavicular joint, although radiography is usually unnecessary. First-line therapy consists of NSAIDs and activity modification.
Patients with adhesive capsulitis typically report decreased range of motion and pain with movement in all directions. On examination, there is loss of both active and passive range of motion with all cardinal shoulder movements and tenderness at the insertion of the deltoid tendon. Plain radiographs are typically normal.
Patients with rotator cuff tears typically have pain with shoulder abduction, internal rotation, or external rotation, depending on the tendon(s) involved. However, a key distinguishing feature of a full-thickness rotator cuff tear is loss of strength. A positive drop-arm test is suggestive of a supraspinatus tear. The absence of weakness and the patient's negative drop-arm test argue against the presence of a rotator cuff tear.
Supraspinatus tendinitis is characterized by pain with active shoulder abduction and a positive painful arc. Internal and external rotation may also elicit pain with involvement of other rotator cuff tendons. Pain is typically elicited with active but not passive range of motion.
Acromioclavicular joint degeneration typically presents with pain located on the superior aspect of the shoulder, tenderness to palpation of the acromioclavicular joint, and pain with shoulder adduction and abduction beyond 120 degrees.
Armstrong A. Evaluation and management of adult shoulder pain: a focus on rotator cuff disorders, acromioclavicular joint arthritis, and glenohumeral arthritis. Med Clin North Am. 2014 Jul;98(4):755-75, xii. [PMID: 24994050]