Biocompatibility of Bone Allograft Toughened with a Novel Sterilization Method for Critically-Sized Segmental Defects: An In Vivo Rabbit Study

PURPOSE: Bone allografts often undergo γ-irradiation to decrease infection risk. This consequently degrades bone collagen and makes the bone brittle. Our laboratory found pre-treatment with ribose could protect the bone. This thesis aimed to determine if ribose-treated γ-irradiated allografts were biocompatible in vivo. MATERIALS AND METHODS: Using the New Zealand White rabbit (NZWr), we first aimed to establish a proper in vivo model to test the graft using intramedullary wire fixation (Study 1), and then tested the biocompatibility of ribose-treated grafts (compared to untreated and conventionally-irradiated grafts) (Study 2). Healing/union was assessed with radiographs, μCT, histomorphometry, backscatter electron microscopy, and torsion testing. RESULTS: Intramedullary fixation achieved stable reconstructions. All grafts achieved bony union. No differences were found in radiographic and biomechanical parameters tested. However, irradiated grafts had less bone volume (p=0.000) but greater bone forming properties (pM.A.S