Lateral external fixation plus K-wire for pediatric supracondylar humeral fracture with medial comminution: a retrospective study of 53 cases in a tertiary medical center.

Background: Medial comminuted supracondylar humeral fracture (SCHF) is a common elbow injury in children, and there is no consensus on treatment yet. While crossed pinning offers biomechanical advantages for medial comminution, it carries inherent risks of iatrogenic ulnar nerve injury. This study aims to describe the surgical technique of lateral external fixation (LEF) combined with K-wire (KW) as an alternative technique and evaluate the clinical and radiological outcomes of this method.

Methods: We retrospectively analyzed 53 children (mean age 7.1 years; 28 males, 25 females) with Gartland type II (n=9) and III (n=44) SCHFs with medial comminution, treated between January 2019 and January 2022. All fractures were fixed with LEF and KW. Functional outcomes were assessed using Flynn's criteria, with radiological parameters (carrying-angle loss, shaft condylar angle, Baumann's angle) measured at a minimum 12-month follow-up (range, 12-26 months).

Results: At last follow-up, radiographic evaluation demonstrated a mean shaft condylar angle of 37.1°±4.4°, Baumann's angle of 75.6°±3.6°, and carrying angle loss of 3.4°±2.0°. Range-of-motion loss averaged 3.5°±2.4°. According to Flynn's criteria, 87% (46/53) achieved excellent and 13% (7/53) good outcomes. Subgroup analysis revealed significantly greater carrying-angle deviation (P<0.01) and motion loss (P=0.05) in Gartland III versus II fractures. Complications included two superficial pin-site infections (3.8%) resolved with oral antibiotics; no instances of iatrogenic nerve injury, vascular compromise, or malunion occurred.

Conclusions: For pediatric SCHF with medial comminution, external fixator (EF) plus KW is a feasible alternative without the risk of iatrogenic ulnar nerve injury.