Objectives: Description of an anatomic condition where a femoroacetabular impingement was identified as the cause for the development of nonunion of the femoral neck.
Design: Retrospective analysis.
Setting: University hospital.
Patients: Three patients, aged 27 to 74 years, in whom, after exclusion of other known factors, a femoroacetabular impingement was identified as the cause for the nonunion of a femoral neck fracture.
Intervention: Surgical correction of the femoroacetabular impingement.
Main outcome measurement: Intraoperative verification of femoroacetabular impingement. Healing of the femoral neck non-union.
Results: In all 3 patients, femoroacetabular impingement was confirmed at surgery. After elimination of the cause for impingement, all nonunions went on to uneventful healing.
Conclusions: A femoroacetabular impingement mechanism is proposed as a cause for nonunion of femoral neck fractures. Predisposing factors such as bulging at the fracture site or decreased femoral-neck offset should be addressed at the time of initial fracture treatment.