The impact of fixation type for intertrochanteric femoral fracture on patient survival

Intramedullary (IM) nail fixation for intertrochanteric fractures is potentially associated with improved postoperative function but may have an increased mortality risk compared to sliding hip screw (SHS) fixation. This study investigated postoperative mortality risk between surgical fixation type for intertrochanteric fracture in patients aged 50 years and older using linked data from the Australian Hip Fracture Registry and National Death Index.Descriptive analysis and Kaplan-Meier survival curves performed unadjusted analysis of mortality and fixation type (short IM nail, long IM nail and SHS). Multilevel logistic regression (AMLR) and Cox modelling (CM) performed adjusted analysis of fixation type and mortality following surgery. Instrumental variable analysis (IVA) was conducted to minimize the effect of unknown confounders.The 30-day mortality was 7.1% for short IM, 7.8% for long IM and 7.8% for SHS fixation (P = 0.2). The AMLR demonstrated significant increase in 30-day mortality risk for long IM nail compared to short IM nail (OR = 1.2, 95% CI = 1.0-1.4, P < 0.05) but no significant difference for SHS fixation (OR = 1.1, 95% CI = 0.9-1.3, P = 0.5). No significant difference between groups and postoperative mortality was demonstrated by the CM at 30-days nor 1-year nor by the IVA at 30-days.Despite a significant increase in 30-day mortality risk for long IM nail compared to short IM nail fixation in the adjusted analysis, this was not demonstrated in the CM nor IVA indicating the role of confounders influencing the regression findings. There was no significant association in 1-year mortality between long IM nail and SHS compared to short IM nail fixation.