Recovery of Motor Nerve Injuries Associated With Displaced, Extension-type Pediatric Supracondylar Humerus Fractures

Background: Nerve injuries occur in approximately 11% of pediatric extension supracondylar humerus fractures (SCHF), yet there is scarce literature to guide clinicians on management. The primary goal of this study was to report the presentation, treatment, and outcome of motor nerve injuries associated with extension SCHF. Our secondary goal was to determine which injury and treatment factors were associated with prolonged motor nerve recovery. Methods: Two hundred forty-four traumatic nerve injuries associated with extension SCHF treated at a single institution between 1996 and 2012 were reviewed. Patients with iatrogenic nerve injuries or subjective paresthesias without motor deficit were excluded. Univariable and multivariable general linear modeling were used to compare recovery times across nerve injury types and to determine the effect of injury and treatment characteristics on recovery time. Results: Patients were a mean age of 6.7 years, with 89% presenting with a single nerve injury and 29% of the cohort experiencing a concurrent vascular injury. The majority of injuries (62%) were to the median nerve. Forty-three (18%) cases had acute nerve decompression at the time of fracture fixation. Five cases required subsequent surgery for poor nerve recovery; none of which underwent initial nerve decompression. Thirty-one patients were lost to follow-up after injury. Median time to nerve recovery was 2.3 months (IQR 1.4 to 3.7 mo); 60% of injuries had nerve recovery by 3 months and 196 (92%) patients had complete nerve recovery at final follow-up. A greater percentage of isolated median nerve (70%) injuries recovered within 3 months compared with radial nerve (42%) injuries (P=0.01). Multivariable analysis demonstrated that multiple nerve injuries took 54% longer to recover than single median nerve injuries (P=0.01), and single radial nerve injuries took 30% longer to recover than single median nerve injuries (P=0.04). Conclusions: The majority of nerve injuries associated with pediatric extension SCHF recover within 6 months without acute nerve decompression. The presence of either an isolated radial nerve injury or multiple nerve injuries is associated with prolonged motor recovery.