Long-term differences in clinical prognosis between crossed- and parallel-cannulated screw fixation in vertical femoral neck fractures of non-geriatric patients

•In comparison with parallel screws, crossed screws can markedly reduce FNS, and potentially reduce NU, AVN rates.•Satisfactory reduction remains the key surgical goal that prevents NU.•The incidence of AVN strongly depends on the initial displacement at the time of injury.