Orthopedic orthopedics alters the bone mineral density of rats submitted to race training

Abstract

Orthopedic orthoses act as therapeutic resources supporting a stricken limb to complement and allow adequate rehabilitation, with the purpose of immobilizing, correcting deviations, protecting or blocking certain structures that have non-physiological movements. The objective of this study was to analyze the impact of orthopedic orthosis on the bone mineral density of rats submitted to running training. The project was approved by the Ethics Committee for the Use of Animals of the State University of Ceará, under the protocol n^o 6923877 of 10/28/2016. Twenty-two female Wistar rats, with the body mass between 210 ± 10g were used. The animals were randomly divided into 3 groups: Control (CTR), Trained (TRE) and Trained with Orthosis (ORT). The animals of the CTR group did not perform the training; the TRE and TRO groups underwent moderate race training. The training took place for three weeks where the first week consisted of a treadmill adaptation. Over the next two weeks the animals underwent a stress test on the first day of the week, and on the next five days, for a training course at 60% of the maximum exertion capacity. The exercise test consisted of continuous races with an increase of 0.2km/h in the intensity of the exercise, until the animal reached exhaustion. After this period, the animals were anesthetized and later dissected to remove the femur and tibia from the hind paws (right and left). The following areas were analyzed: epiphysis (proximal and distal), diaphysis and bone length. Statistical analysis was used ANOVA One way with Brown-Forsythe and Kruskal-Wallis test, considering difference with p <0.05. Results were expressed as average ± standard error. It was verified that structurally there were few metric alterations in the analyzed areas, emphasizing diaphysis reduction in the tibia and femur of the TRE group in comparison to the CTR. Moreover, epiphyseal increase in the femur of the TRE group in relation to the CTR. However, it was verified that the TRO group promoted statistically significant alterations in the bone mineral density of the analyzed areas. Therefore, we conclude that the use of the orthopedic orthosis can influence structurally the bone mineral density, as well as it can attenuate the effects of the bone overload during the race training.