Comparison of standard versus reconstruction proximal interlocking screw configurations for antegrade intramedullary nail fixation of femoral shaft fractures.

Background: The standard proximal interlocking screw (SS) configuration for antegrade intramedullary nail (IMN) fixation of femoral shaft fractures is lateral to medial or from the greater to less trochanter. Some authors argue for the routine use of the reconstruction screw (RS) configuration (oriented up the femoral neck) instead to prevent femoral neck complications. The purpose of this study was to compare a matched cohort of patients receiving these screw configurations and subsequent complications.

Methods: A retrospective review of two urban level-one trauma centers identified adults with isolated femoral shaft fractures undergoing antegrade IMN. Patients with RS and SS configurations were matched 1:1 by age, sex, fracture location, and AO classification in order to compare complications.

Results: 130 patients with femoral shaft fractures were identified. SS and RS configurations were used in 83 (64%) and 47 (36%) patients. 30 patients from each group were able to be matched for analysis. The RS and SS group did not differ in age, fracture location, AO classification, operative time, or number of distal interlocking screws. The RS group had fewer open fractures and were more likely to have two proximal screws. There were 7 complications, including 5 nonunions and 2 delayed unions, with no detectable difference between RS vs. SS groups (10% vs 13%, Proportional difference -3%, 95% confidence interval (CI) -30 to 14%, p = 0.1). There were no femoral neck complications in the entire cohort of 130 patients. On multivariate analysis none of the variables analyzed were independently associated with the development of complications.

Conclusions: In this matched cohort of patients with femoral shaft fractures undergoing antegrade IMN fixation, RS and SS configurations were associated with a similar number of complications and no femoral neck complications. The SS configuration remains the standard for antegrade IMN femoral shaft fixation.

Level Of Evidence: Level III, Retrospective cohort study.