What damage accompanies a surgical neck of humerus fracture?

Associated Damage with Surgical Neck of Humerus Fractures

Surgical neck of humerus fractures are commonly associated with neurovascular injuries, particularly to the axillary nerve and axillary artery, which can significantly impact morbidity, mortality, and quality of life outcomes.

Neurovascular Complications

Nerve Injuries

• Axillary nerve injury is the most common neurological complication with proximal humeral fractures, especially with surgical neck fractures 1
• Brachial plexus irritation or injury can occur, particularly with fracture dislocations 2
• The proximity of the surgical neck to the neurovascular bundle makes these structures vulnerable during displacement of fracture fragments

Vascular Injuries

• Axillary artery injury can occur with surgical neck fractures, particularly when there is medialization of the shaft fragment 3
• This is a potentially life-threatening complication with reported mortality cases 3
• Signs of vascular compromise include:
  • Absent or diminished pulses at the wrist
  • Pale, cold hand
  • Decreased perfusion

Soft Tissue Damage

• Rotator cuff tears are highly associated with proximal humeral fractures 1
• Significant hemarthrosis is typically present in the acute setting 1
• Glenohumeral joint capsule injuries may occur
• Surrounding muscle damage, particularly to the deltoid

Diagnostic Considerations

Imaging for Associated Injuries

• CT is the preferred imaging modality for characterizing fracture patterns and assessing displacement 1
• 3D-reformatted CT images help visualize fracture displacement and angulation 1
• MRI can detect associated rotator cuff tears but is generally inferior to CT for fracture characterization 1
• Ultrasound can identify full-thickness rotator cuff tears in ideal conditions but is limited in acute settings due to swelling and decreased mobility 1

Management Implications

• Vascular compromise requires immediate attention:

  • Fractures with absent pulses and underperfusion may require exploration of the antecubital fossa 1
  • Fracture dislocations with plexus irritation are an acute indication for operation 2

• Nerve injuries may influence treatment approach:

  • Primary radial nerve paresis is considered a relative indication for surgery 2
  • Secondary radial nerve paresis is an absolute indication for operation 2
  • Axillary nerve paresis may be observed for up to 8 weeks before surgical exploration 2

Potential Long-Term Complications

• Avascular necrosis of the humeral head (particularly with high surgical neck fractures)
• Malunion requiring potential corrective osteotomy 4
• Nonunion of the fracture site
• Persistent neurological deficits
• Shoulder stiffness and reduced range of motion
• Post-traumatic arthritis

Clinical Pitfalls to Avoid

• Failing to assess neurovascular status thoroughly in all patients with surgical neck fractures
• Overlooking subtle signs of vascular compromise that may progress to limb-threatening ischemia
• Delaying treatment in cases with vascular injury, which can lead to increased morbidity and mortality
• Underestimating the potential for axillary nerve injury, which can significantly impact functional outcomes

The presence of these associated injuries significantly influences treatment decisions and patient outcomes, making thorough neurovascular assessment essential in all cases of surgical neck fractures of the humerus.