Nonunion in Pediatric Femoral Neck Fractures

Abstract

➢ Nonunion is the third most common complication of femoral neck fractures in children after osteonecrosis and premature physeal closure causing coxa vara.➢ The most common cause of nonunion of a femoral neck fracture in developed countries is failure of fixation or loss of reduction, whereas in developing countries, it is delayed presentation.➢ Most failures of fixation, if identified in time (<3 months), retain adequate bone contact. Hence, removal of the offending implant, refixation without bone-grafting, and valgus osteotomy to correct the biomechanical forces by converting the vertical fracture line into a horizontal fracture line provide adequate results with respect to osseous union.➢ In patients with a delayed presentation, the intervening fibrous tissue and resorption of the neck pose challenges. In these patients, in addition to performing a valgus osteotomy and fixation, in situ stabilization across the fibrous tissue and reconstruction of the inferomedial aspect of the neck using fibular strut-grafting, which adds stability, bone contact, and biological material, provide adequate union.

Fractures of the Proximal Femur in Childhood: A Review

“…The prevalence of non-union in paediatric femoral neck fractures has been reported to range from 0 to 44% [60]. The primary cause for non-union is failure to achieve or maintain adequate reduction [20,43,[61][62][63].…”

“…Non-union is most common in type II, and least common in type IV Delbet fractures [22]. In a review of 24 studies including 110 cases of non-union, 65% were type II fractures; 29% type III; 6% type I; and 0% type IV [60]. Fracture displacement, vertical orientation of fracture line, and damage to proximal femoral vascularity are other injury-related factors that contribute to poor fracture healing [16,61,62,64].…”

“…Fracture displacement, vertical orientation of fracture line, and damage to proximal femoral vascularity are other injury-related factors that contribute to poor fracture healing [16,61,62,64]. Non-union used to be common in fractures treated nonoperatively [2]; with recent trends towards internal fixation, non-union rates have declined [18,19,60,65]. Nevertheless, it is still seen in fractures fixed in poor reduction [16,43,63]; fixed using less rigid implants (threaded pins/ Kirschner wires) [60,64]; and when fixation does not cross the physis thus compromising stability [22,66].…”

“…Non-union used to be common in fractures treated nonoperatively [2]; with recent trends towards internal fixation, non-union rates have declined [18,19,60,65]. Nevertheless, it is still seen in fractures fixed in poor reduction [16,43,63]; fixed using less rigid implants (threaded pins/ Kirschner wires) [60,64]; and when fixation does not cross the physis thus compromising stability [22,66]. Delayed presentation remains an important cause for non-union in developing countries [7,39].…”

“…Non-union and AVN frequently co-exist, however, this is not a contra-indication for surgery. In fact, once union is achieved, the femoral head tends to revascularize in children, and clinically significant collapse may not occur [60]. Sanghavi et al [60] recently described an algorithm for the management of non-unions depending upon the underlying cause.…”