Dual energy X-Ray absorptiometry: desenvolvimento, validação e reprodutibilidade de recomendações técnicas para osteoartrite de ratos

Abstract

Objective: The aim of the present study is to develop, validate and make reproducible standardized anatomical regions of interest for bone mineral density (BMD) and bone mineral content (BMO) of rat knee at different times of osteoarthritis (OA) by formulating a guide to recommendations techniques for using dual energy X-ray absorptiometry (DXA). Methodology: 7 male winstar rats were used, divided into 2 groups entitled Osteoarthritis (OA) (n=6) and Test (T) (N=1). The OA group underwent transection of the anterior cruciate ligament for OA induction in the 14th week. The animals were anesthetized and scanned by DXA at the 14th, 19th and 24th weeks. After the scan, all images of the animals were analyzed using the software in specific and high-resolution small animal mode (resolution: 311 μm²) and anatomical regions of interest were made in the bones often associated with OA of the knee, femur and tibia. they were named Distal Femur and Proximal Tibia. In sequence, the technical recommendations guide was developed, validated and made reproducible, with norms and standardizations of the techniques for using the DXA, containing specific guidelines for the pre and post-test and preparation of regions of interest. The evaluators were divided into two groups with 2 members each, the evaluators were classified as experienced and inexperienced. Training was carried out to perform the positioning of the animal and selection of regions of interest for experienced and inexperienced evaluators. The evaluators carried out the proposed activities following the new recommendation guide made without any interference from the researcher using the group T mouse. Results: The validations of the regions of interest together with the formulation of technical recommendations formulated a valid and reliable basis for evaluating the BMD and CMO at different times of knee OA. Conclusion: The uses of the validated regions of interest and the recommendations guide make analyzes objective and less biased, increasing the efficiency of research standardization.