Differential Diagnosis for Right Shoulder Injury

The patient's symptoms and mechanism of injury suggest several possible diagnoses. These can be categorized based on their likelihood and potential impact on the patient's health.

• Single Most Likely Diagnosis

  • Acromioclavicular (AC) joint sprain or separation: This is considered the most likely diagnosis due to the direct impact to the shoulder during the fall, which is a common mechanism for AC joint injuries. The increase in pain with forced movement and limited range of motion, particularly with lifting the arm, also supports this diagnosis.

• Other Likely Diagnoses

  • Rotator cuff strain or tear: Given the mechanism of injury and the patient's symptoms, including pain with movement and limited range of motion, a rotator cuff injury is a plausible diagnosis. The rotator cuff is prone to injury from falls onto the shoulder.
  • Proximal humerus or clavicular fracture: Although less likely, these fractures could occur from a direct fall onto the shoulder. The initial pain rating and the increase in pain with movement could be indicative of a fracture, especially if the fracture is nondisplaced or minimally displaced.

• Do Not Miss Diagnoses

  • Brachial plexus injury: Although the patient denies numbness or tingling, a brachial plexus injury could present with pain and limited mobility, especially if the injury is partial or involves specific nerve roots. This diagnosis is critical to identify early due to the potential for long-term neurological deficits.
  • Vascular injury: A direct blow to the shoulder could potentially injure the subclavian artery or vein, leading to significant complications, including bleeding or thrombosis. Early recognition is crucial for timely intervention.

• Rare Diagnoses

  • Osteonecrosis of the humeral head: This condition could be a late complication of a shoulder injury, particularly if there was significant trauma to the joint. It is less likely in the acute phase but should be considered if the patient's symptoms persist or worsen over time.
  • Septic arthritis or osteomyelitis: Infection is a rare but potential complication of any injury. If the patient develops signs of infection, such as increased redness, warmth, swelling, or fever, these diagnoses must be considered and promptly treated to avoid serious consequences.

Each of these diagnoses has a different set of implications for treatment and prognosis, highlighting the importance of a thorough evaluation, including imaging studies and potentially specialist consultation, to determine the most accurate diagnosis and appropriate management plan.