Fixation of femoral neck fractures in patients younger than 65 years: a retrospective descriptive study at a high-volume trauma centre

BACKGROUND: The management of femoral neck fractures in the younger patient remains contentious, with high failure rates being reported in the literature. Patient age usually plays a major role during decision-making with regard to head-sparing versus head-sacrificing surgical strategies. The aim of this study was to review the outcomes of fixation of femoral neck fractures in patients younger than 65 years in an attempt to identify factors that might predict fixation failure. METHODS: A retrospective study, evaluating the outcome of fixation of femoral neck fractures in patients younger than 65 years of age was conducted. Factors affecting the outcome of treatment were explored in an attempt to identify variables that might predict fixation failure. RESULTS: The final cohort comprised 51 men (76%) and 16 women (24%) with a mean age of 43.9±12.2 years (95% CI 41.0-46.8; range 23-64) and a median follow-up of 8.7 months (IQR 6.2-17.4). Thirteen patients (19%) presented with undisplaced (Garden I and II) fractures while 54 (81%) presented with displaced (Garden III and IV) fractures. Twenty-four patients (36%) met the definition of failure. These included 15 cases (22%) of non-union, seven cases (10%) of femoral neck collapse and two cases (3%) of avascular necrosis. Sixteen patients (24%) underwent conversion to total hip arthroplasty. All cases of failure occurred in patients who presented with Garden III and IV displaced fractures. Factors associated with failure included the presence of fracture comminution (p<0.001) and the increased vertical orientation of the fracture line according to the Pauwels classification (p<0.001). Neither patient age (p=0.117), time from injury to surgery (p=0.204), mechanism of injury (p=0.136), smoking (p>0.999) nor alcohol abuse (p=0.528) was associated with failure CONCLUSION: The incidence of fixation failure following surgical management of femoral neck fractures in patients younger than 65 years of age remains high. While undisplaced fractures heal readily regardless of time from injury to surgery, mechanism of injury or fixation method, displaced fractures remain a difficult problem to solve. In our series, fixation failure was observed in one in three patients, while one in four required revision to total hip arthroplasty. Level of evidence: Level 4.