Femoral Neck Stress Fracture: Can MRI Grade Help Predict Return-to-Running Time?

Background:Limited research is available regarding return-to-running (RTR) time after femoral neck stress fractures. While studies have shown the prognostic value of image-based grading scales for stress fractures at other sites, few have included femoral neck stress fractures.Purpose:To determine if the grade of femoral neck stress fractures based on magnetic resonance imaging (MRI) characteristics correlates with RTR time.Study Design:Cohort study; Level of evidence, 3.Methods:This study included 24 patients (mean age, 32.9 years; range, 18-51 years) who were diagnosed with 27 femoral neck stress fractures by MRI from 2009 to 2015 at a single sports medicine clinic. All fractures were compression sided and were treated nonoperatively. Charts were reviewed for patient demographics and RTR time. Images were graded from 1 to 4 using the Arendt stress fracture severity scale. Statistical analysis was performed using survival analysis and Cox proportional hazard model to compare the RTR time between grades. ...