Flexion-Type Supracondylar Humeral Fracture with Ulnar Nerve Injury in Children: Two Case Reports and Review of the Literature

BACKGROUND: Supracondylar humeral fracture is a common fracture in the pediatric population. Although extension-type is the most common fracture pattern (97% to 98%), flexion-type supracondylar fractures are rarely encountered (2% to 3%). The combination of a flexion-type supracondylar humeral fracture with an ulnar nerve injury represents a real challenge for an orthopaedic surgeon.
CASE REPORT: We report 2 cases of flexion-type supracondylar humeral fracture with ulnar nerve injury that open reduction and fixation was necessary because closed reduction could not achieve an acceptable result. An anterior approach to the elbow joint was chosen to explore whether any neurovascular structures were entrapped between the fragments. The ulnar nerve was not found to be compressed in the fracture site. After anatomic reduction, cross K-wire fixation of the fracture was performed. At 6-month follow-up, ulnar nerve injuries (in both patients) were resolved.
CONCLUSIONS: These case reports enhance the existing literature that flexion-type supracondylar fractures with ulnar nerve injury are associated with higher rates of open reduction. Orthopaedic surgeons should be aware, and family members of those patients should be informed, that the likelihood of an open reduction in these types of injuries is extremely high. Open reduction is needed not only to achieve an anatomic reduction of the fracture but to make sure that the ulnar nerve is not entrapped between the proximal and distal fragment.

Keywords: Accessory Nerve Injuries, Child, Fracture Fixation, Internal, humeral fractures, Ulnar Nerve