Failure Patterns of Femoral Neck Fracture Fixation in Young Patients

The primary purpose of this study was to describe the failure patterns of femoral neck fracture fixation in young patients. The secondary purpose was to determine if pattern of failure varies by type of implant. Adult patients (age range, 18-55 years) who experienced a "fixation failure" following internal fixation of a femoral neck fracture were identified from 5 level 1 trauma centers. Failure was defined by screw cutout, implant breakage, varus collapse (<120° neck-shaft angle), or severe fracture shortening (≥1 cm). When multiple complications were identified, mechanical failures were preferentially noted for the analysis. Failure patterns were compared between patients who received multiple cancellous screws and patients who received a sliding hip screw plus a derotation screw. Severe fracture shortening was the most common complication identified (61%). No differences in the incidence of severe shortening (P=.750) or implant breakage (P=1.000) were detected between the fixation groups. However, among the failures with a sliding hip screw plus a derotation screw construct, a greater portion were related to screw cutout (38% for a sliding hip screw plus a derotation screw vs 7% for screws, P=.019). Failures with multiple screws were associated with varus collapse (25% for screws vs 0% for a sliding hip screw plus a derotation screw, P=.037). Severe shortening was the most common fixation failure. Sliding hip screw plus derotation screw implants were associated with screw cutout. Multiple cancellous screw implants failed by varus collapse. Selecting a surgical implant based on its likely failure pattern may allow surgeons to minimize the severity of failure or the need for secondary conversion to hip arthroplasty. [Orthopedics. 2019; 42(4):e376-e380.].