Supracondylar Humerus Fractures: When Lateral Entry Pins Are Not Enough

Percutaneous pin configuration for the management of pediatric supracondylar humerus fractures has been studied extensively both in the biomechanics laboratory and in the clinical setting. Medial entry pins (ie, crossed pinning) increase supracondylar humerus fracture construct stability under certain loading conditions. However, there are noted drawbacks of medial entry pinning, specifically the risk of iatrogenic ulnar nerve injury. In most circumstances, the additional biomechanical stability of crossed pinning is unlikely to be clinically necessary for maintenance of fracture alignment, but there are scenarios in which medial entry pins should be strongly considered. It is important to review the biomechanics of various pin configurations in the setting of pediatric supracondylar humerus fractures, discuss the indications for medial entry pinning (crossed pinning), and discuss a safe technique for applying medial entry pins when indicated.