Varus displacement of intertrochanteric femur fractures on injury radiographs is associated with screw cutout.

Abstract

The purpose of this study was to determine if varus displacement of intertrochanteric femur fractures on injury radiographs is associated with screw cutout after fixation. A retrospective review performed at two urban level 1 trauma centers identified 334 patients with intertrochanteric femur fractures treated with either a cephalomedullary nail (CMN) or a sliding hip screw (SHS). Median patient age was 75 years, 69% were female and 46% had unstable fractures. Varus fracture displacement on injury radiographs, defined as the most proximal aspect of the femoral head being at or below the most proximal aspect of the greater trochanter, was present in 38% of patients. Screw cutout was recorded. Varus displacement was associated with unstable fracture patterns (62% vs. 37%, difference (D) 25%, 95% confidence interval (CI) 15-35%), female gender (77% vs. 64%, D 13%, CI 3-22%) and poor/adequate reductions (54% vs. 41%, D 13%, CI 2-23%). Cutout occurred in 9 (3%) patients, 8 of which had varus displacement. There was no detectable difference, with wide confidence intervals, between patients that did and did not experience cutout in terms of age, gender, unstable fractures, implants, tip-apex distance (TAD) or poor/adequate reductions. On univariate and multivariate analysis, varus displacement was the only variable associated with cutout. Patients with and without varus displacement had a cutout incidence of 6 and 0.5% (Odds ratio 13, CI 1.6-108). Intertrochanteric fractures presenting with varus displacement were more likely to experience cutout. This potential risk factor for cutout warrants further study. Level 3, retrospective cohort.