Examining Preoperative Risk Factors for Nerve Injury in Pediatric Monteggia Fracture-Dislocations.

Background: The risk factors for fracture-related nerve injury in pediatric Monteggia fracture-dislocations are not well understood. As such, this study aimed to determine the incidence of, and preoperative risk factors for, nerve injury in pediatric Monteggia fracture-dislocations.

Methods: Patients aged ≤18 years with acute Monteggia or Monteggia-equivalent fracture-dislocations that underwent reduction in the operating room, including closed reduction and casting under general anesthesia and internal fixation of the ulnar fracture with or without opening the radiocapitellar joint, from 2011 to 2021 were retrospectively identified. Exclusion criteria included reduction in the emergency department, concomitant ipsilateral upper-extremity fractures, malunions, or patients without preoperative imaging. Nerve function was assessed preoperatively, and nerve injury was defined as persistent motor and/or sensory deficits on postoperative examination. Patients were followed until nerve-related symptoms resolved. Logistic regression controlled for age and fracture pattern to determine preoperative risk factors.

Results: Of 148 patients (mean age, 6.4 ± 2.8 years), 18.2% (27) had preoperative nerve injury. The posterior interosseous nerve (PIN) was injured in 15 patients, the anterior interosseous nerve (AIN) was injured in 7 patients, and other nerves were injured in 6 patients. All the nerve injuries resolved spontaneously, with a mean resolution time of 63.6 days (range, 8 to 150 days). Risk factors for nerve injury included patient age of ≥8 years (odds ratio [OR], 7.7; 95% confidence interval [CI], 2.6 to 22.8; p < 0.001), lateral radial head dislocation (OR, 6.8; 95% CI, 2.0 to 22.4; p = 0.002), an open fracture (OR, 4.5; 95% CI, 1.2 to 16.5; p = 0.025), and a comminuted ulnar fracture (OR, 4.1; 95% CI, 1.4 to 12.2; p = 0.012). PIN injury was associated with lateral radial head dislocation (p < 0.001) and a comminuted ulnar fracture (p < 0.001). AIN injury was associated with an open fracture (p = 0.002) and diaphyseal ulnar fracture (p = 0.004).

Conclusions: The incidence of preoperative nerve-related injury in pediatric Monteggia fracture-dislocations was 18.2%. Risk factors for preoperative nerve injury included patient age of ≥8 years, lateral radial head dislocation, an open fracture, and a comminuted ulnar fracture. All the nerve injuries resolved within 150 days, suggesting that early operative intervention may be unnecessary.

Level Of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.