The use of the femoral neck system (FNS) leads to better outcomes in the surgical management of femoral neck fractures in adults
Abstract
A meta-analysis of 509 adult femoral neck fractures comparing the novel Femoral Neck System (FNS) against traditional Cannulated Cancellous Screws (CCS). Data confirms FNS provides superior angular stability, significantly reducing non-union and femoral neck shortening.
The End of the Cannulated Screw Era?
Key Finding
"FNS reduced the risk of complications by 75% (OR 0.25, p < 0.001) and femoral neck shortening by 71% (OR 0.29, p < 0.001) compared to screws."
Background: Cannulated screws (CCS) have long been the standard for young adult femoral neck fractures despite high failure rates, particularly in unstable Pauwels Type 3 patterns. The lack of angular stability often leads to varus collapse and neck shortening. The Femoral Neck System (FNS) was engineered to combine the minimally invasive benefits of screws with the angular stability of a DHS, but comparative clinical data was previously fragmented.
Methods: This meta-analysis synthesized data from 8 retrospective studies comprising 509 patients (Mean age ~50.8 years). The authors compared FNS (n = 230) vs. CCS (n = 279). Primary endpoints included complication rates, femoral neck shortening, time to union, and Harris Hip Scores (HHS). Statistical pooling utilized a random-effects model for heterogeneous data (I² > 50%).
Results: FNS demonstrated decisive clinical superiority. Patients treated with FNS achieved union significantly faster (Mean Difference -0.92 months, p = 0.002) and had higher functional outcomes (HHS + 4.12 points, p < 0.001). Crucially, the sliding bolt design of the FNS mitigated the risk of femoral neck shortening (Odds Ratio 0.29). While FNS was associated with marginally higher blood loss (+ 16.5 mL, p < 0.001), operative time was statistically equivalent to screws (p = 0.24).
Conclusion: The FNS offers a definitive biomechanical and clinical upgrade over cannulated screws for adult femoral neck fractures. By preventing neck shortening and ensuring faster union, it should be considered the new standard of care for preserving the native hip in young patients.