Pinning of supracondylar fractures in children - Strategies to avoid complications

Abstract

In the pediatric population supracondylar humerus fracture (SHF) is one of the most common injuries. Diagnosis is based on inspection and conventional radiography. SHFs should be classified according to the modified Gartland classification, which guides treatment. Non-displaced or minimally displaced fractures (Gartland type-I) should be treated non-operatively, completely displaced type III fractures require closed reduction and K-wire fixation. In type-II fractures, important landmarks, such as the anterior humeral line (Roger´s line), the shaft-physeal angle (Baumann´s angle) and the shaft condylar angle should be considered to guide treatment. Special attention has to be paid for potential rotational dislocation, which is indicated by a ventral spur. In such cases surgery is necessary. The degree of acceptable extension malpositioning depends on patient´s age. In 10-year-old children fractures with a shaft condylar angle of more than 15° are still suitable for non-operative therapy. Timing for surgery is controversially discussed. Postponing surgery to the next day seems reasonable if absence of pain, intact soft tissue and normal neurovascular status are present. Neurovascular complications are not uncommon, especially in Gartland type-III fractures and in cases with additional forearm injuries. A white hand without palpable pulse needs emergency surgery, the management of the pulseless pink hand is still controversially discussed. Different operative techniques exist for surgical treatment. The golden standard is closed reduction and percutaneous K-wire pinning. Crossed pinning seems to achieve best biomechanical stability. Since ulnar nerve injuries are reported to occur in 6% after medially inserting K-wires, lateral divergent insertion of two K-wires has been compared to crossed pinning fixation in several randomized controlled trials. Meta-analyses demonstrated a higher risk for ulnar nerve injury for the crossed pinning technique while risk for loss of fixation was higher in lateral only pinning. In both cases, K-wires should be removed 3-6 weeks after surgery with consolidation of the fracture. Clinical and radiological follow-up should be carried out at 3 weeks post fracture fixation to rule out loss of reduction. If this should occur, early revision surgery has been demonstrated beneficial.

Keywords: K-wire; Pinning; Supracondylar humerus fracture; Ulnar nerve.