Geometrical restoration and component positioning after hip arthroplasty for femoral neck fracture

In this study, the restoration of leg length and global femoral offset and positioning of the femoral stem and acetabular cup of hemiartroplasty (HA) and total hip arthroplasty (THA) after femoral neck fracture (FNF) were compared at the postoperative radiographs between 181 hips operated using the direct lateral (DL) approach and 127 hips operated using the posterolateral (PL) approach. Regarding HA, the DL approach was associated with lengthening of the operated leg (5.7 mm vs. 2.1 mm), p=0.001. The PL approach had more varus stem position (23% vs. 12%, p=0.03) and the DL approach had more stems with C-position (58% vs. 32%, p=0.001). Regarding THA, the DL approach showed increased cup anteversion (28° vs. 21°), p=0.016, and a decrease in FO (-5.9 mm vs. -2.0 mm, p=0.04). Surgeons caring for FNF patients are to be aware of the differences in geometrical restroration and component positioning between the two approaches.