Fixation failure following femoral neck system fixation for intracapsular femoral neck fractures: Association with fracture orientation.

PURPOSE: To evaluate fixation failure following femoral neck system fixation (FNS) for intracapsular femoral neck fractures (FNF) and to determine whether fracture characteristics, particularly fracture orientation, were associated with fixation failure.

METHODS

A retrospective cohort study was performed at a Level I trauma center. 82 patients with intracapsular femoral neck fractures treated with FNS fixation were included. Fixation failure was defined as implant cut-out, loss of fixation, nonunion, or revision surgery. Associations between fracture characteristics and fixation failure were evaluated.

RESULTS

The mean age was 70.1 ± 12.7 years, with a mean follow-up of 22.2 ± 10.2 months. Eight fixation failures occurred (9.8%). Pauwels classification was significantly associated with fixation failure (p < 0.001), with higher-angle fractures demonstrating increased risk of failure. No failures occurred in Pauwels type I fractures, whereas failures occurred in Pauwels type II and III fractures. Fracture morphology (subcapital, including valgus impacted vs transcervical) and Garden classification were not associated with fixation failure (p = 1.000 and p = 1.000, respectively). One case of distal locking screw breakage was observed; however, most fixation failures were associated with fracture orientation rather than implant-related mechanical failure.

CONCLUSION

Fixation failure following femoral neck system fixation appears to be primarily associated with fracture orientation rather than implant-related mechanical failure. The low rate of implant-related mechanical complications suggests that the FNS provides adequate biomechanical stability for intracapsular femoral neck fracture fixation, whereas vertical fracture patterns remain a major determinant of fixation failure.