Femoral Neck Shortening After Hip Fracture Fixation Is Associated With Inferior Hip Function: Results From the FAITH Trial.

Abstract

To describe the distribution of femoral neck shortening after internal fixation and to determine whether shortening is associated with inferior hip function at 24 months after a hip fracture in patients 50 years of age or older. Retrospective cohort study. A secondary analysis of data from 81 clinical centers included in the Fixation using Alternative Implants for the Treatment of Hip Fractures (FAITH) trial. Three hundred fifty patients, 50 years of age or older, who had an isolated femoral neck fracture and underwent timely operative fixation of the fracture. Femoral neck shortening was measured as a categorical variable and classified into one of the following groups, as determined by the Central Adjudication Committee: no shortening, mild shortening (≤5 mm), moderate shortening (6-10 mm), or severe shortening (>10 mm). The primary outcome for the current analysis was hip function, as measured by the Western Ontario & McMaster Universities Osteoarthritis Index questionnaire, at 24 months after injury. Two-thirds of patients had no or mild shortening (≤5 mm), whereas one-third of patients had moderate or severe shortening (>5 mm). After adjusting for surgical treatment, a greater amount of femoral neck shortening was found to be associated with poorer hip function (P < 0.01). We found that increasing femoral neck shortening was associated with inferior hip function. Although internal fixation often results in successful union, patients who heal in a shortened position report poorer functional outcomes. Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.