What is the prognosis for a patient with a radial nerve lesion and humeral fracture after Open Reduction Internal Fixation (ORIF)?

Prognosis of Radial Nerve Lesion with Humeral Fracture Post-ORIF

The prognosis for radial nerve recovery after humeral fracture ORIF is excellent, with 90-100% of patients experiencing recovery, though the timeline extends from 4 weeks to 18 months, with most recovery occurring between 7-9 months. 1, 2

Expected Recovery Rates and Timeline

Overall recovery rates are highly favorable:

• 90% of radial nerve injuries associated with humeral fractures recover spontaneously 1
• One surgical series demonstrated 100% recovery when early exploration and decompression were performed during ORIF 2
• Another surgical cohort showed 75% good recovery with plate fixation 3
• A large retrospective study found 91% of traumatic nerve injuries improved (72% complete, 19% partial recovery) 4

Recovery timeline follows a predictable pattern:

• Initial signs of recovery typically appear at 7-9 weeks post-injury 4
• Median recovery time is 26 weeks (approximately 6 months) 2
• Wrist extension recovers first (average 3 months), followed by finger extension 2-6 weeks later 2
• If no recovery by 7 months, probability of recovery by 18 months is still 56% 1
• If no recovery by 12 months, probability drops to 17% 1

Factors Affecting Prognosis

Injury characteristics that worsen prognosis:

• Concomitant vascular injury significantly reduces recovery rates (33% nerve transection rate vs. 7.3% without vascular injury) 4
• Open fractures are associated with higher nerve transection rates (22.7% vs. 6.8% in closed fractures) 4
• Nerve transection portends worse prognosis: only 40% recovery vs. 95.3% for nerves in continuity 4
• Multiple nerve palsies indicate worse outcomes 4

Timing of surgical intervention:

• Earlier ORIF correlates with better nerve recovery (statistically significant correlation between surgical delay and recovery delay) 3
• ORIF within 3 days showed good recovery in 75% of cases 3
• However, operative treatment of the fracture itself does not change the overall rate of nerve recovery compared to conservative management (88.5% vs. 100%) 4

Clinical Management Algorithm

Immediate assessment (at presentation):

• Document radial nerve function: wrist extension against gravity (Medical Research Council grade), finger extension, thumb extension, and sensation 1, 2
• Determine if palsy is preoperative (83% of cases) or postoperative (17% of cases) 1
• Assess for vascular injury and open fracture, which indicate higher risk of nerve transection 4

Intraoperative decision-making:

• When performing ORIF, nerve exploration and decompression can be considered, particularly for distal third fractures 2
• In 70% of cases where nerve is visualized, it remains in continuity; neurolysis may be performed 3
• Nerve transection is found in 14.1% of explored cases and requires immediate repair 4

Postoperative monitoring protocol:

• Assess nerve function every 2 months until recovery 2
• If no signs of recovery by 9 weeks, obtain nerve conduction studies 4
• Watchful waiting is appropriate for at least 7 months, as recovery probability remains >50% 1
• Consider nerve reconstruction, nerve transfers, or tendon transfers only after 12 months if no recovery 1

Functional Outcomes

Long-term disability is minimal in recovered patients:

• QuickDASH scores average 9 (range 0-59) after recovery 3
• 85% of patients return to previous physical activities 3
• Disability of Arm, Shoulder and Hand (DASH) scores range from 0-11.8 at >1 year post-operatively 2

Critical Pitfalls to Avoid

Do not perform early nerve surgery (<7 months) in the absence of confirmed transection, as the probability of spontaneous recovery remains high and early intervention is unlikely to be beneficial 1

Do not assume postoperative palsy indicates iatrogenic injury—only 4.6% of nerve palsies after ORIF are iatrogenic, and most represent continuation of the initial traumatic injury 4

Do not delay ORIF unnecessarily when surgery is indicated for fracture management, as earlier fixation (within 3 days) correlates with better nerve recovery 3

Recognize that absence of visible nerve injury during ORIF does not guarantee recovery—in 30% of cases, the nerve may not be visualized during surgery 3