What is the immediate management for a patient with a suspected acute fracture at the inferior margin of the acromion, presenting with approximately 3.8 mm cephalocaudal cortical bone step-off?

Immediate Management of Suspected Acute Acromion Fracture

For a patient with a suspected acute acromion fracture showing 3.8 mm cortical step-off, immobilize the extremity in a sling for comfort, provide appropriate analgesia, and obtain orthopedic consultation without attempting to manipulate or straighten the injury. 1

Initial Stabilization and Pain Control

• Do not move or attempt to straighten the injured extremity, as this provides no benefit and may cause further injury 1
• Immobilize the shoulder immediately using a sling in the position of comfort 1
• Provide appropriate analgesics tailored to patient comorbidities as soon as possible, before completing all diagnostic investigations 1, 2
• Start with regular paracetamol (acetaminophen) unless contraindicated, adding opioids as needed 2
• Avoid NSAIDs if renal function has not been assessed, as approximately 40% of trauma patients have moderate renal dysfunction 2
• Document pain scores at rest and with movement before and after analgesia administration 2

Diagnostic Imaging Approach

Radiography is the first-line imaging modality for evaluating suspected acromion fractures 1

• Obtain a complete shoulder radiographic series including true anteroposterior view of the glenoid, scapular Y view, and axillary view 3
• If the fracture extent, displacement, or comminution is uncertain on radiographs, CT with metal reduction protocol should be obtained to further delineate the fracture 1
• CT is particularly useful for detecting acromial stress fractures that may be radiographically occult 1
• MRI can identify occult fractures by detecting associated marrow edema and fracture lines when radiographs and CT are negative 1

Assessment for Associated Injuries

Acromion fractures, particularly those of the anatomic acromion and extremely lateral scapular spine, are frequently associated with other shoulder injuries that must be excluded 4:

• Evaluate for coracoid base fractures 4
• Assess for acromioclavicular joint injury 4
• Examine for rotator cuff involvement 1
• Check neurovascular status, particularly axillary nerve function 5

The mechanism is typically indirect force from the lateral direction for fractures of the anatomic acromion 4.

Orthopedic Consultation and Definitive Management

• Activate orthopedic consultation for all displaced acromion fractures (step-off of 3.8 mm indicates displacement) 5
• Most acromion fractures can be managed conservatively with sling immobilization, pain control, and early mobilization as pain allows 1
• Displaced fractures may require operative fixation with tension banding or plate osteosynthesis, particularly when there is significant displacement 5
• Surgery is more commonly needed for type I fractures (anatomic acromion and extremely lateral scapular spine) compared to type II fractures (more medial spine) 4

Early Mobilization Strategy

• Begin early mobilization as the patient's pain allows 1
• Patients should remain pain-free before gradually increasing activity levels 6
• Initiate physical therapy for range-of-motion exercises once acute pain subsides 1
• Avoid overly aggressive physical therapy during the acute healing phase (first 6-8 weeks) as this can impede fracture healing 6

Critical Monitoring and Red Flags

Red flags requiring urgent reassessment include 6:

• Progressive neurological deficits
• Severe uncontrolled pain despite appropriate analgesia
• Inability to participate in basic activities of daily living

Common Pitfalls to Avoid

• Do not assume all acromion fractures are benign stress fractures—many result from direct trauma and may have significant displacement requiring surgery 7
• Do not delay orthopedic consultation for displaced fractures, as early operative intervention may optimize outcomes 5
• Avoid premature aggressive mobilization, which can compromise fracture healing 6
• Do not overlook associated injuries, particularly coracoid fractures and AC joint disruption 4