To analyze the influences of fracture level and comminution, time to operation and reduction quality on the results of displaced femoral neck fractures in young adults.

From January 1996 to January 2003, 39 of 51 cases of displaced femoral neck fractures that were treated with closed reduction and percutaneous internal fixation using cannulated screws, were evaluated after at least two years of follow-up with respect to the fracture level, comminution, time to operation, and reduction quality.

The incidence of AVN and non-union were 6/39 (15.4%) and 3/39 (7.7%), respectively. The differences in the incidences of complications among subcapital, transcapital, and subcapital fractures was not significant (p=1 & p=1). There was a higher incidence of AVN (p=0.0066) and non-union (p=0.0219) with posterior comminutions than anterior ones. The time to operation was not an important factor in influencing the development of complications (p=0.4984 & p=1). Between acceptable and poor reductions, the differences in the incidences of AVN was significant (p=0.0105), but not in the incidences of non-unions (p=0.1011).

We concluded that good quality of reduction is more important than the time to operation for achieving good results, and that comminution is a more important prognostic factor than is the fracture level.