Complications of femoral neck fracture in young adults.

Femoral neck fractures are uncommon but serious injuries in young adults, with high rates of nonunion and avascular necrosis reported. This study was undertaken to examine the relationship between the mechanism and severity of injury, anatomic site of fracture, health status, and method of therapy on the incidence of these complications in young adults. The hospital records of 32 skeletally mature patients between the ages of 15 and 50 years (mean, 33) treated for femoral neck fracture between 1975 and 1982 were reviewed, and data analyzed for the 25 patients with a minimum 2-year followup (mean, 61 months). Data pertaining to the cause of injury, fracture pattern, prior health status, overall injury severity, method of fracture treatment, and long-term outcome were analyzed. Nonunion of the fracture site was observed in five (20%); avascular necrosis in nine (36%). Of patients with subcapital fracture 83% developed nonunion or avascular necrosis, compared to 21% with true femoral neck fracture (p = 0.05). There was no difference in cause of injury, overall injury severity, degree of comminution, displacement, method of treatment, or prior health status between those with and without complications. In this study, high rates of nonunion and avascular necrosis were seen after all types of femoral neck fracture in young adults, but were more often associated with subcapital fracture. These complications of hip fracture appeared to be independent of health status, method of treatment, or mechanism or severity of injury.