@article{d6b4a8b9906d4146a0f6effbd62d9808,
title = "Image Analysis Software as a Strategy to Improve the Radiographic Determination of Fracture Healing",
abstract = "Objectives: To develop and validate an unbiased, accurate, convenient, and inexpensive means of determining when an osseous defect has healed and recovered sufficient strength to allow weight bearing. Methods: A novel image processing software algorithm was created to analyze the radiographic images and produce a metric designed to reflect the bone strength. We used a rat femoral segmental defect model that provides a range of healing responses from complete union to nonunion. Femora were examined by x-ray, micro-computed tomography and mechanical testing. Accurate simulated radiographic images at different incident x-ray beam angles were produced from the micro-computed tomography data files. Results: The software-generated metric (SC) showed high levels of correlation with both the mechanical strength (tMech) and the polar moment of inertia (pMOI), with the mechanical testing data having the highest association. The optimization analysis yielded optimal oblique angles uB of 125 degrees for tMech and 50 degrees for pMOI. The Pearson R2 values for the optimized model were 0.71 and 0.64 for tMech and pMOI, respectively. Further validation using true radiographs also demonstrated that the metric was accurate and that the simulations were realistic. Conclusions: The preliminary findings suggest a very promising methodology to assess bone fracture healing using conventional radiography. With radiographs acquired at appropriate incident angles, it proved possible to accurately calculate the degree of healing and the mechanical strength of the bone. Further research is necessary to refine this approach and determine whether it translates to the human clinical setting.",
keywords = "Animal model, Bone healing, Computer model, Image analysis software, Load bearing, Radiology",
author = "Jeffrey Duryea and Christopher Evans and Vaida Glatt",
note = "Funding Information: This project was funded by a Building Innovative Research Teams Award (R01AR050243-09S1) from NIAMS (parent R01: R01AR050243). This work was conducted with support from Harvard Catalyst/The Harvard Clinical and Translational Science Center (National Center for Advancing Translational Sciences, National Institutes of Health Award UL1 TR001102) and financial contributions from Harvard University and its affiliated academic healthcare centers. The content is solely the responsibility of the authors and does not necessarily represent the official views of Harvard Catalyst, Harvard University and its affiliated academic healthcare centers, or the National Institutes of Health. This study was supported by NIH/NIAMS R01AR050243-S. The authors thank Dr Anna Woloszyk for her assistance with the figures. Funding Information: Twenty-five male, Sprague-Dawley rats, weighing 310–330 g, were used for this study. Rat femoral, mid-diaphyseal, 5 mm defects were stabilized with external fixa-tors providing 4 different degrees of axial stiffness.24,25The defect healing was enhanced using 5.5 mg of rhBMP-2 delivered on an absorbable collagen sponge, the same product as is used clinically (Infuse, Minneapolis, MN). Details of the surgical procedure are given in ref. 26. Animal care and experimental protocols were followed in accordance with National Institutes of Health guidelines and approved by Beth Israel Deaconess Medical Center Institutional Animal Care and Use Committee. This study was funded by a Building Innovative Research Teams grant from National Institute of Arthritis and Musculoskeletal and Skin Diseases. This mechanism is specifically designed to encourage the use of resources developed by a parent R01 grant for an additional purpose. In this case, the parent R01 grant supported the study of bone healing in a rat femoral defect model. This generated rats with a spectrum of different healing responses, whose mCT, radiograph, and mechanical testing data were used here. Publisher Copyright: {\textcopyright} 2018 Lippincott Williams and Wilkins. All rights reserved.",
year = "2018",
month = sep,
day = "1",
doi = "10.1097/BOT.0000000000001234",
language = "English (US)",
volume = "32",
pages = "E354--E358",
journal = "Journal of Orthopaedic Trauma",
issn = "0890-5339",
publisher = "Lippincott Williams and Wilkins",
number = "9",
}