Intramedullary nailing using K-wires for high-energy distal humeral metaphyseal-diaphyseal fractures accompanying radial nerve palsy in a 2-year-old toddler: A case report.

Rationale: Pediatric distal humeral diaphyseal fractures are rare and challenging to manage due to anatomical and biomechanical complexities. In addition, humeral shaft fractures in adults are often accompanied by radial nerve paralysis (RNP), but there are no studies on the incidence or treatment of pediatric humeral shaft fractures accompanied by RNP in toddlers. The authors present the outcomes of closed reduction and intramedullary nailing using Kirschner wires (K-wires) for high-energy distal humeral metaphyseal-diaphyseal open fractures accompanied by RNP in a toddler. This case report aims to highlight an effective surgical approach and its outcomes in a toddler, providing insights for clinicians facing similar scenarios.

Patient Concerns: A 23-month-old boy was referred to our emergency room after several hospital visits. He complained of pain in his right arm and presented wrist drop due to a crushing injury by a conveyor belt. A 1 cm open wound was located at the lateral side of the elbow.

Diagnosis: The patient was diagnosed with an open displaced fracture in the distal third of the right humerus on radiographic examination and RNP was diagnosed on the basis of physical examination.

Interventions: The authors initially attempted open reduction and internal fixation of the fracture using a Steinmann pin after radial nerve exploration, which confirmed continuity of the normal radial nerve, but fixation failed. Reduction loss and displacement progressed with pin migration the day after surgery, and revision surgery was selected. Closed reduction and intramedullary nailing using K-wires were performed on day 2 after the primary surgery.

Outcomes: The patient recovered his ability to extend the wrist and metacarpophalangeal joint approximately 3 weeks after surgery. At the 1-month and 6-month follow-up, the fracture had healed, and radial nerve function had recovered completely.

Lessons: Intramedullary nailing using K-wires for metaphyseal-diaphyseal fractures of the humerus in toddlers is an effective operative treatment. Among them, high-energy open fractures accompanied by radial nerve palsy might require nerve exploration.