Humeral Shaft Fracture

Snapshot

• A 63-year-old man presents to the emergency room with left arm pain after falling off the second step of his ladder. He has significant pain over the middle of his left arm. On exam, he is tender to palpation along the middle of his left arm and a small deformity is appreciated. He has weakness in wrist extension and metacarpal phalangeal joint extension. Radiographs of his left arm demonstrate a spiral midshaft humeral fracture. He is placed in a coaptation splint and discharged with plans to follow-up in one week.

Introduction

• Clinical definition
  • fracture of the humeral shaft
• Epidemiology
  • incidence
    • account for approximately 3% of all fractures
    • increasing incidence in the elderly
  • demographics
    • bimodal age distribution
      • fragility fractures in the elderly
      • high-energy traumatic fractures in younger patients
  • risk factors
    • osteoporosis
• Etiology
  • low-energy injury in elderly patients
  • high-energy injury in younger patients
• Pathoanatomy
  • normal anatomy
    • spiral groove (also known as the radial sulcus) is a shallow depression in the center of the lateral border of the humerus bone
      • radial nerve and deep brachial artery course along the spiral groove of the humerus
• Associated conditions
  • radial nerve palsy
  • forearm fractures
  • shoulder dislocation
• Prognosis
  • favorable
    • low-energy injuries
  • unfavorable
• high-energy injuries

Presentation

• Symptoms
  • arm pain
  • weakness
• Physical exam
  • deformity may or may not be appreciated depending on the location and severity of the fracture
  • neurovascular examination before and after reduction is critical to identify radial nerve palsy or deep brachial artery injury
    • radial nerve palsy (5-10%) results in loss of 
      • wrist extension (wrist drop) 
      • metacarpal phalangeal joint extension
• thumb abduction and extension

Imaging

• Radiography 
  • indication
    • always indicated if a humeral shaft fracture is suspected
  • findings
    • fracture patterns can vary
      • spiral, transverse, and comminuted
    • fracture locations can vary
• proximal, midshaft, and distal

Differential

• Distal humerus fracture
  • distinguishing factor
    • radiographs will demonstrate a fracture in the supracondylar, lateral condylar, or medial condylar zones of the distal humerus
• Proximal humerus fracture
  • distinguishing factor
• radiographs will demonstrate a fracture in the surgical neck or anatomic neck of the proximal humerus

Treatment

• Nonoperative
  • coaptation splint followed by functional bracing
    • indication
      • most humeral shaft fractures can be treated conservatively
• Operative
  • open reduction and internal fixation (ORIF)
    • indication
• severe fractures (e.g., open fractures and vascular injury requiring repair)

Complications

• Radial nerve palsy 
  • neuropraxia
    • most resolve over 3 months of observation