What is the appropriate management for a patient with a humeral mid shaft fracture and suspected nerve impingement after a fall on an outstretched arm?

Management of Humeral Mid Shaft Fracture with Nerve Impingement

For a humeral mid shaft fracture with suspected nerve impingement after a fall on an outstretched arm, surgical management with open reduction and internal fixation (ORIF) combined with nerve exploration is recommended, especially when there are signs of vascular compromise or persistent neurological deficit after initial management. 1

Initial Assessment and Classification

• Immediately assess neurovascular status, particularly looking for:

  • Signs of radial nerve injury (most common): wrist drop, decreased sensation over dorsal first web space
  • Median nerve function: thumb opposition, sensation to index/middle fingers
  • Vascular status: pulse, capillary refill, hand temperature and color

• Obtain appropriate radiographs to classify the fracture pattern and displacement

Management Algorithm

Step 1: Initial Stabilization

• Immobilize the fracture with a posterior splint or sling
• Perform detailed neurovascular examination and documentation
• Obtain high-quality orthogonal radiographs

Step 2: Definitive Treatment Decision

For mid-shaft humeral fractures with nerve impingement:

1. Surgical Management (Recommended):

   • ORIF with nerve exploration is indicated for:
     • Displaced fractures with nerve deficit
     • Open fractures
     • Vascular compromise
     • Multiple trauma patients
     • Bilateral fractures
     • Floating elbow injuries

2. Timing of Surgery:

   • Urgent surgical intervention (within hours) is required if there is vascular compromise 1
   • Early exploration (within days) is recommended for nerve deficits associated with fracture 2

Step 3: Surgical Technique

• Approach based on fracture pattern and nerve involved (typically anterolateral or posterior)
• Careful nerve identification and neurolysis
• Fracture reduction and stable fixation
• Consider shortening osteotomy if needed for tension-free nerve repair in cases of neurotmesis 3

Post-operative Management

• Early finger motion to minimize stiffness
• Regular neurovascular checks
• Structured rehabilitation program
• EMG/NCS at 6 weeks if no nerve recovery is observed
• Consider tendon transfers if no recovery by 6 months

Clinical Considerations and Pitfalls

1. Nerve Injury Assessment:

   • Radial nerve is most commonly injured in humeral shaft fractures (11-18% of cases) 4
   • Document baseline nerve function before any manipulation
   • Distinguish between neuropraxia (most common) vs. neurotmesis

2. Surgical Exploration Timing:

   • Immediate exploration is indicated for:
     • Open fractures
     • Vascular injury
     • Progressive neurological deficit
     • Nerve laceration suspected (sharp injury)
   • Delayed exploration (3-4 months) may be considered for closed injuries with no recovery 5

3. Avoid Common Pitfalls:

   • Failure to recognize and document nerve injury at initial presentation
   • Inadequate immobilization leading to secondary displacement
   • Overly aggressive manipulation during reduction
   • Delayed treatment of vascular compromise
   • Failure to explore the nerve when indicated

4. Special Situations:

   • Combined nerve injuries (median and radial) require more aggressive surgical exploration 6
   • In cases of complete nerve transection, primary repair is preferred when possible 3

The American Academy of Orthopaedic Surgeons suggests that surgical exploration is mandatory when vascular compromise persists after reduction due to the catastrophic risks of inadequate perfusion, including limb loss, ischemic muscle contracture, nerve injury, and functional deficit 1.

International surveys indicate a trend toward more aggressive management of humeral shaft fractures with associated nerve palsy, with surgeons preferring ORIF with acute exploration of the nerve 2.