Femoral neck system as a safe alternative to cannulated compression screw and dynamic hip screw in femoral neck fractures: an early comparative study

Abstract Introduction: The femoral neck system (FNS) is a safe alternative to cannulated compression screw (CCS) and dynamic hip screw (DHS) in femoral neck fractures. Methods: A dual-centre retrospective cohort study was performed on femoral neck fractures (AO type 31-B) treated with closed reduction and internal fixation using FNS, DHS or CCS between April 2016 and April 2020. Exclusion criteria were as follows: patients aged below 16 years; chronic fractures beyond 7 days; pathological fractures; fracture extension to the intertrochanteric region or ipsilateral neck and shaft fractures; and open fractures. A total of 85 patients were identified: FNS ( n = 28), DHS ( n = 29) and CCS ( n = 28). Results: The FNS and CCS groups had a lower Garden and Pauwels classification compared to the DHS group (both P < 0.001). Both FNS and CCS groups were comparable in postoperative orthopaedic complications (10.7% [ n = 3] vs. 3.6% [ n = 1], adjusted P = 0.321). The DHS group had more postoperative orthopaedic complications than the FNS group, but this was not statistically significant (27.6% [ n = 8] vs. 10.7% [ n = 3], adjusted P = 0.321). There were no significant differences in median time to radiological union or median femoral neck shortening at union (both P > 0.05) among the three groups. Conclusion: The new DePuy Synthes FNS is a safe alternative to CCS with comparable complication rates for femoral neck fractures that are less displaced and more stable. The FNS also appears to be a safe alternative to DHS in the fixation of femoral neck fractures for the few cases of high-energy femoral neck fractures.