A 45-year-old woman comes to the physician because of a 10-week history of right shoulder pain that worsens with reaching overhead. The pain often disturbs her sleep, especially when lying on the affected side. She has no history of trauma or significant medical conditions and is not on any medication. On physical examination, there is no visible muscle atrophy. There is tenderness on palpation immediately below the acromion. Active abduction of the right shoulder is limited to 110 degrees without resistance and with resistance is limited due to pain. Neurological examination reveals no weakness or other deficits, and peripheral pulses are normal. X-rays of the right shoulder show no abnormalities.
D) Rotator cuff tendinopathy
The rotator cuff is includes the subscapularis, teres minor, supraspinatus, and infraspinatus which seat the humeral head directly into the center of the glenoid during shoulder motion. They work together to internally and externally rotate, abduct, and adduct the shoulder. Rotator cuff tendinopathy is a common cause of shoulder pain in adults, especially following overhead activity that involves raising the affected arm. There is little evidence of inflammation, so the terminology has changed from tendinitis to tendinopathy. It often causes pain that limits the ability to participate in overhead activities, with symptoms worsening at night and during certain motions. Diagnosis is primarily clinical, with tenderness over the rotator cuff and pain during abduction being key findings. X-rays are typically normal, while ultrasonography and magnetic resonance imaging (MRI) can detect tendinopathy. Treatment includes rest, NSAIDs, and physical therapy.
Answer choice A: Accessory nerve palsy, is incorrect. This condition typically presents with weakness in shoulder elevation and muscle atrophy over time, which is not seen in this patient.
Answer choice B: Acromioclavicular separation is incorrect. This condition usually follows direct trauma to the shoulder and presents with pain localized to the acromioclavicular joint, not consistent with this patient's history or examination.
Answer choice C: Occult fracture of the proximal humerus, is incorrect. This diagnosis would usually present with a significant trauma history and abnormal X-rays, neither of which are present in this case.
Answer choice E: Suprascapular nerve palsy, is incorrect. This condition typically presents with weakness in shoulder abduction and external rotation and muscle atrophy over time, which are not observed in this patient.
Key Learning Point
Rotator cuff tendinopathy is a common cause of shoulder pain that often worsens with overhead activity and at night. Diagnosis is primarily clinical, supported by imaging modalities like ultrasonography and MRI, with treatment focusing on rest, NSAIDs, and physical therapy.
