Cubitus Valgus

Abstract

Cubitus valgus is a relatively uncommon problem following elbow fractures in children. The primary etiology is lateral condylar nonunion that drifts into a valgus deformity. Late presentation is common with deformity and/or ulnar nerve symptoms. The root cause is often an underappreciation of acute lateral condylar fracture management (discussed under acute lateral condylar fractures). The acute fracture has a large cartilaginous component and extends into the radiocapitellar or ulnohumeral joint. Any disruption of the epiphyseal cartilage increases the probability of displacement and allows synovial fluid into the fracture site. Osteoblasts cannot cross a fluid barrier and nonunion results with insufficient healing between the lateral condylar fragment and distal humerus. Subsequently, progressive valgus deformity ensues with increasing fracture fragment displacement and deformity over time. Tardy ulnar nerve palsy can result due to ongoing stretch of the ulnar nerve.