OBJECTIVES

: Intramedullary nailing (IMN) for femur fractures has become more popular in recent years but can be associated with various mechanical complications. The purpose of this study is to determine the rates of mechanical complications and evaluate factors associated with mechanical complications that occur over two years following IMN.

METHODS

: This retrospective observational cohort analysis used the IBM® Marketscan® Medicare Supplemental database (2010-2017). All patients 65 years or older with a claim for IMN for femur fractures (trochanteric, intertrochanteric and subtrochanteric) in an inpatient setting were included. The date of IMN was defined as the index date. Overall mechanical complication rates were determined at two-years post-index hospital discharge; and independent factors associated with mechanical complications were evaluated using multivariable logistic regression.

RESULTS

: A total of 36,544 patients with IMN for trochanteric, intertrochanteric, subtrochanteric or combinations of these femoral fractures were identified. The mean (standard deviation, SD) age for the cohort was 83.7 (7.6) years and 72.4% were female with multiple comorbidities – more than 50% of patients had an Elixhauser 3 or above. Crude rates of mechanical complications at the 2-year time point were 3.91% for intertrochanteric only, 8.76% for subtrochanteric only, 4.82% for trochanteric only and 4.51% for any fracture type. Results from the logistic regression analysis showed that subtrochanteric fractures were the greatest risk factor (odds ratio (OR): 4.72, 95% confidence interval (CI): 3.38-7.07), followed by rheumatoid arthritis (OR: 4.64, 95% CI: 3.00-8.15). Osteoporosis was also a significant risk factor (OR: 3.22, 95%CI: 2.59-4.17).

CONCLUSIONS

: Femoral fractures treated by IMN had an overall mechanical failure rate of 4.51% within 2 years after implant. Risk factors included subtrochanteric fracture site, rheumatoid arthritis and osteoporosis. The results from this study indicate treatment of femoral fractures with IMN is associated with generally low rates of mechanical failure 2 years after implant.