Treatment of displaced femoral neck fractures in young patients with DHS and its association to osteonecrosis☆

Objective The purpose of this study is to evaluate the performance of dynamic hip screw for the treatment of dislocated femoral neck fractures in young patients, focusing on osteonecrosis. Methods A series of 53 patients with less than 55 years of age were retrospectively evaluated. All patients had dislocated femoral neck fractures (Garden III or IV) and were treated with DHS. Ficat's staging system was used to evaluate avascular necrosis. Results There were 38 (71.7%) males and 15 (28.3%) females, with an overall mean age at the onset of fracture of 41.9 years (±12.8). According to Garden's classification, 21 (39.6%) fractures were classified as type III and 32 (60.4%) were considered totally dislocated, Garden IV. Fracture healing was achieved in 39 patients (73.6%). Thirteen cases of avascular necrosis were observed (24.6%). Conclusions The incidence of avascular necrosis in young patients with a displaced femoral neck fractures treated with DHS was 24.6%. No statistically significant association was found between times elapsed to surgery, fracture displacement, and presence of derotation screw with osteonecrosis. Level of evidence IV.