[Translated article] Fixation of adult femoral neck fractures: Retrospective comparison between cannulated screws and femoral neck system (FNS)

Objective

The FNS System DePuy Synthes® (EEUU, 2018) represents a recent alternative treatment for the fixation of femoral neck fractures, providing biomechanical advantages with respect to cannulated screws (3 CS). The objective of this study is to compare the clinical results of both fixation methods.

Method

A retrospective collection of the 36 subcapital fractures treated with the FNS system was carried out compared with a retrospective search of the last 35 patients treated with 3 CS. Age, sex, fracture pattern, delay until the intervention, length of intervention, hospital length stay, and haemoglobin loss were analysed. In addition, the rate of avascular necrosis, nonunion, symptomatic femoral neck shortening, and material protrusion with or without its removal were recorded during a minimum follow-up of 6 months.

Results

No significant differences were found in age (p-value 0.32), fracture patterns (p-value 0.77), surgical delay (p-value 0.28), surgical time (p-value 0.226), length of hospital stay (p-value 0.921) and blood loss (p-value 0.086) between the two groups.

A significantly higher overall complication rate was observed in the group treated with cannulated screws (p-value 0.004). Analysed separately, a higher rate of avascular necrosis, symptomatic shortening of the femoral neck, protrusion of the osteosynthesis material with or without removal was observed in the group treated with cannulated screws.

Conclusions

The FNS system represents a safe and reproductible alternative for the fixation of femoral neck fractures, showing non-inferior outcomes to treatment with cannulated screws.