Risk factors for cut-out after internal fixation of trochanteric fractures in elderly subjects.

Introduction: 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.

Methods: 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.

Results: 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.

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

Level Of Evidence: IV, retrospective study.