Can a radial nerve lesion make it difficult for a patient to heal from a humeral fracture?

Radial Nerve Lesion Does Not Impair Humeral Fracture Healing

A radial nerve lesion does not make it difficult for a patient to heal from a humeral fracture—bone healing occurs independently of nerve function. The nerve injury and fracture are separate pathologies that require concurrent but distinct management approaches.

Understanding the Relationship Between Nerve Injury and Fracture Healing

Bone Healing is Independent of Nerve Function

• Humeral fracture healing proceeds through normal biological processes (hematoma formation, callus development, remodeling) regardless of radial nerve status 1
• The radial nerve injury represents a soft tissue complication that occurs alongside the fracture but does not interfere with osseous union 2
• Most radial nerve injuries associated with humeral fractures are neuropraxias or axonotmesis that resolve spontaneously without affecting bone healing 2

The Clinical Challenge is Evaluation, Not Healing

• The primary difficulty with concurrent radial nerve injury is clinical assessment, not fracture healing 3
• When multiple upper extremity injuries coexist (fracture plus nerve injury), evaluating nerve recovery becomes challenging but does not impede bone union 3
• Radial nerve injury is the most common peripheral nerve complication of humeral shaft fractures, occurring in approximately 10-18% of cases 1

Management Algorithm for Humeral Fracture with Radial Nerve Injury

Initial Assessment

• Perform early postoperative physical assessment to detect peripheral neuropathy, as recommended by the American Society of Anesthesiologists 4
• Document baseline radial nerve function (wrist extension, thumb extension, finger extension at MCPs) before any manipulation 1
• Distinguish between primary nerve injury (present at initial presentation) versus secondary injury (developing after manipulation or surgery) 5

Treatment Decision-Making

For Primary Radial Nerve Palsy (present at injury):

• Conservative management is preferred, as most resolve spontaneously 2
• Proceed with fracture stabilization (operative or non-operative) based on fracture characteristics, not nerve status 1
• Observe for nerve recovery with serial examinations 2
• Explore the nerve only if no clinical or electromyographic evidence of recovery by 3.5-4 months post-injury 2

For Secondary Radial Nerve Palsy (develops after manipulation/surgery):

• This represents an absolute indication for surgical exploration 5
• Immediate surgical intervention is warranted as this suggests nerve entrapment or iatrogenic injury 5

Intraoperative Considerations

• Avoid prolonged pressure on the radial nerve in the spiral groove of the humerus during positioning, as recommended by the American Society of Anesthesiologists 4
• This positioning concern relates to perioperative neuropathy prevention, not fracture healing 4

Expected Outcomes

Fracture Healing

• Humeral fractures heal at normal rates regardless of radial nerve injury status 1
• Union rates are determined by fracture pattern, stability, and patient factors—not nerve function 2

Nerve Recovery

• With primary nerve injuries managed conservatively, 92% achieve complete return of radial nerve function 2
• Surgical outcomes show motor recovery to Grade 3 or better in 80-98% depending on repair type 6
• Only 8% of primary radial nerve palsies require surgical exploration 2

Critical Pitfalls to Avoid

• Do not delay fracture treatment waiting for nerve recovery—treat the fracture based on its characteristics 1
• Do not explore primary nerve palsies prematurely—wait 3.5-4 months unless secondary palsy develops 2
• Do not assume nerve injury affects bone healing—these are parallel processes requiring separate monitoring 1
• Do not miss secondary nerve palsy—this requires immediate surgical intervention unlike primary injuries 5

Monitoring Strategy

• Serial clinical examinations to assess both fracture healing and nerve recovery 4
• Electromyographic studies at 3-4 weeks can help distinguish neuropraxia from axonotmesis 2
• Radiographic assessment of fracture union proceeds on standard timeline regardless of nerve status 1
• If unremitting pain develops during follow-up, reevaluate for complications as recommended by the American Academy of Orthopaedic Surgeons 4