Optimal Treatment of Malignant Long Bone Fracture: Influence of Method of Repair and External Beam Irradiation on the Pathway and Efficacy of Fracture Healing

The purpose of this project is to characterize the differential effects of radiation on the two pathways of fracture healing in an established animal model of bilateral femur fracture repair. Micro CT data obtained from 18 animals in the year 1 SOW (Group I) have been analyzed to assess callus volume and character. Data on RNA isolation and PCR array on 18 animals in the year 1 SOW (Group II) are being analyzed at the partner lab at University of Maryland. Surgical procedures consisting of bilateral femur fracture and repair have been completed on both planned study cohorts (Groups III and IV; total of 40 animals) in the year 2 SOW; all animals were imaged and have been sacrificed according to protocol schedule. Both 6 month (Group III) and 3 month (Group IV) specimens underwent biomechanical testing, and data have been analyzed. Surgical procedures on the bilateral plate group of 9 animals recently added by amendment are being performed. Year 3 SOW animal procedures in Group V for histological testing will begin on schedule in the ninth quarter of the award.