Nerve Injuries Following Pediatric Supracondylar Humerus Fractures-A Systematic Review and Meta-Analysis.

Background: Nerve palsy complicates pediatric supracondylar humerus fractures (SCHFs) and creates uncertainty regarding observation versus exploration. We synthesized contemporary evidence on incidence, injury patterns, recovery, and management of traumatic and iatrogenic nerve injuries. Methods: A systematic review of PubMed, Scopus, and Web of Science was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. Pediatric SCHF studies reporting nerve injury incidence or neurological outcomes were included. The literature search covered all records through December 2022, was updated in October 2023, and was rerun through January 2026. Random-effect meta-analysis pooled proportions for overall, traumatic, and iatrogenic nerve injuries, with subgroup analysis by nerve involved. Management and recovery were synthesized descriptively. Results: Forty studies involving 6,850 children were included; 30 contributed to quantitative synthesis. The occurence of any nerve injury was reported in 11.3% (95% confidence interval [CI], 10-13%). Traumatic palsy predominated and most commonly involved the median/anterior interosseous nerve (AIN) complex (59.7%), followed by radial (25.1%) and ulnar (15.2%) nerves. Iatrogenic palsy occurred in 3.7% (95% CI, 2.8-4.6%) of surgically treated fractures and was predominantly ulnar. Recovery was excellent, with most deficits resolving within 2-6 months; median/AIN palsies recovered fastest and ulnar palsies slowest. Contemporary-only sensitivity analysis (2000-2024) yielded similar estimates. Conclusions: Approximately one in 10 displaced SCHFs is associated with nerve palsy, usually a transient traumatic neuropraxia. Observation with serial examinations is appropriate for most closed, well-perfused injuries. New postoperative ulnar palsy that is clearly pin related may improve with early pin removal or repositioning. Surgical exploration should be reserved for selective indications, including entrapment, vascular compromise requiring exploration, progressive deficit, or lack of recovery by 4-6 months. Key Concepts: (1)Incidence and natural history: Nerve palsy accompanies approximately 11% of displaced pediatric supracondylar humerus fractures and is most often a transient traumatic neuropraxia with an excellent prognosis.(2)Nerve-specific injury patterns: Median/anterior interosseous nerve palsy predominates in extension-type fractures, whereas ulnar nerve palsy is more common in flexion-type injuries, reflecting predictable biomechanical displacement patterns.(3)Traumatic vs iatrogenic nerve injuries: Traumatic nerve deficits present preoperatively in most cases and typically recover with observation, while iatrogenic nerve palsies are less common (3-4%), predominantly ulnar, and associated with medial pin placement.(4)Management and recovery: Structured observation with serial neurological examinations is appropriate for most closed, well-perfused injuries; recovery is near-universal, usually within 2-6 months, with median/anterior interosseous nerve palsies recovering fastest.(5)Indications for intervention: Routine immediate nerve exploration is not indicated in the absence of red flags. Early medial pin removal may expedite recovery in clearly pin-related ulnar palsy, while surgical exploration should be selective (entrapment, vascular injury, or no improvement by 4-6 months). Level of Evidence: IV (systematic review of case series).