Proximal femoral fracture is associated with severe morbidity and mortality and high socioeconomic costs. The main mechanical complication of internal fixation in trochanteric fracture is lag-screw cut-out through the femoral head. Several factors are involved, but remain controversial. The aim of the present study was to determine risk factors for cut-out in internal fixation of extracapsular proximal femoral fracture.

A single-center retrospective study was conducted on a continuous series of 228 patients aged over 75 years, operated on for trochanteric fracture by gamma3 nail or DHS screw plate between July 2009 and December 2014.

Thirteen patients experienced mechanical failure of the internal fixation (5.7%). Tip-apex distance (TAD) differed significantly between the group with cut-out (32.69mm) and the group with consolidation (23.70mm; p-value=0.003052). Cut-out rate was 0.89% in good reduction, versus 9.64% in moderate and 12.12% in poor reduction (p-value=0.002693). In contrast, there were no significant differences according to age, type of fracture, or severity of osteoporosis.

To minimize mechanical complications exacerbating morbidity and mortality, great attention should be paid to fracture reduction and lag-screw positioning.

IV, retrospective study.