LAUSR

INTRODUCTION The reported rate of nonunion of distal femoral fractures varies in the literature. Several risk factors for nonunion following lateral locked plating (LLP) have been described. We aimed to study the rate of nonunion, and risk factors thereof, in a Swedish population where fragility fractures are common. A secondary aim was to study risk factors for reoperation for any cause. PATIENTS AND METHODS We retrospectively reviewed the hospital files and radiographs of all adult patients admitted to our institution with a distal femoral fracture, from 2004 through 2013. In cases treated with LLP, medical comorbidities, fracture characteristics and implant characteristics were analysed as potential risk factors for nonunion, defined as any surgical intervention to improve healing. RESULTS There were 8 cases (4%, 95%CI: 1.8-8.1%) of nonunion in 191 fractures treated with LLP. Patients with nonunion were younger: 62 vs. 81 years (p = 0.009) and more commonly had open fractures: 38% vs. 9% (p = 0.034). No patient 80 years or older had a surgical intervention for nonunion. Lower age was independently associated with reoperation for any cause, but not for nonunion. DISCUSSION The low rate of nonunion in this study is probably due to the fact that we present data from a complete cohort from a geographic catchment area. Referral centres with a high proportion of young patients with high-energy injuries, may be better suited for studies on risk factors for nonunion, due to higher statistical power. However, results from such institutions may not be generalizable to the more common low-energy fractures.