Differential Diagnosis for Shoulder Pain

The patient presents with full range of motion (ROM) but reports pain with extension, flexion, and abduction. Based on these symptoms, the following differential diagnoses are considered:

• Single Most Likely Diagnosis

  • Subacromial Impingement Syndrome: This condition is characterized by pain when moving the shoulder, especially with abduction and flexion, due to the compression of the rotator cuff tendons under the acromion. The patient's symptoms align closely with this diagnosis, making it the most likely.

• Other Likely Diagnoses

  • Rotator Cuff Tendinitis: Inflammation of the tendons of the rotator cuff can cause pain during movements such as flexion, extension, and abduction. Given the patient's symptoms, this is a plausible diagnosis.
  • Bursitis: Inflammation of the bursae around the shoulder joint can cause pain with movement, similar to what the patient is experiencing. This could be related to or separate from rotator cuff issues.
  • Adhesive Capsulitis (Frozen Shoulder): Although typically associated with limited ROM, early stages or mild cases might present with pain on movement without significant restriction, making it a consideration.

• Do Not Miss Diagnoses

  • Fracture: A fracture, especially of the humerus or scapula, could cause pain with movement and must be ruled out, even if the patient has full ROM. Missing a fracture could lead to improper healing and significant long-term disability.
  • Septic Arthritis: Infection within the joint can cause severe pain with any movement and is a medical emergency. Prompt diagnosis and treatment are crucial to prevent joint destruction.
  • Neer's Syndrome (Rotator Cuff Tear with Retraction): A significant tear in the rotator cuff can lead to chronic pain and disability. Early diagnosis is key for effective management.

• Rare Diagnoses

  • Osteonecrosis of the Humeral Head: A condition where the blood supply to the humeral head is interrupted, leading to bone death. It can cause shoulder pain but is less common and typically associated with specific risk factors.
  • Polymyalgia Rheumatica: An inflammatory condition that affects the muscles, leading to pain and stiffness, particularly in the shoulder region. It's more common in older adults and can be associated with other systemic symptoms.
  • Referred Pain from Cervical Spine: Sometimes, pain from the cervical spine can refer to the shoulder area. Although less likely given the specific movements causing pain, it's a consideration, especially if there are other symptoms like neck pain or radiculopathy.