Change of Volume and Mechanical Properties of Femoral Bone in Rabbits at Different Ages with Knee Osteoarthritis under Sand-therapy / 生物医学工程学杂志

The present paper is aimed to study the effect of sand-therapy with Uyghur medicine on biomechanical properties and femoral bone volume of the femur of osteoarthritis (OA) rabbits at two different ages. In the experiments, we injected Papain through the joint space of right knees into the bodies of New Zealand rabbits (16 in the growing group, and 16 in the mature group), and established an OA model. The 16 rabbits in the mature group were divided randomly into 2 sub-groups: 8 in control group (no sand therapy), and 8 sand-therapy group. The 16 rabbits in the growing group were divided randomly into 2 groups as well: 8 in the control group (no sand therapy), and 8 in the sand-therapy group. We carried out CT scanning four times (1 day before, 13th, 27th and 41st days after the establishment of the model, respectively). After importing the CT data to MIMICS, the different volumes of each sclerotin were recorded and change of the percentage of each sclerotins in total femur bone volume were analyzed. Finally the rabbit femurs were given three-point bending test, the elastic load and the elastic deflection were obtained and the inertia of the section, the maximum bending stresses, the bending modulus of elasticity and the structural rigidity were calculated. The experimental results showed that (1) Compared with 1 day before and 13th day after establishment of model at maturity, the cancellous bone volume increased and cortical bone volume decreased (P < 0.05), but compared with those in the control group, the cancellous bone volume of femurs decrease and cortical bone volume increased under sand-therapy (P < 0.05). Compared with those in the control group, there were no significant changes in the deflection and cross-sectional moment of inertia in the sand-therapy group (P > 0.05), but the maximum bending normal stress, maximum load, elastic modulus, and structural stiffness (P < 0.05) in the sand therapy group were larger than those in the control group. The study showed that sand-therapy in Uyghur medicine has benign effect on bone volume of the OA rabbit femur in two ages and the mechanical properties of the OA rabbit femur at the two ages induced by sand-therapy in Uyghur medicine have been improved.

Analysis on changes of sclerotin volume during the self-repairing process of bone defect / 生物医学工程学杂志

Bone maintenance theory considers that the external load is the direct stimulating source of the bone remodeling. In this article, the method of experimental observation of self-repairing process of the bone defect and related results are introduced. Firstly, a hole was drilled in the rabbit thighbone so that the continuity of the bone was changed. Then bone defect model was established, and the thighbone data were obtained by using CT scanning, and the self-repairing process of bone defects caused by growth factor were observed and analyzed by MIMICS software. Finally, the relationship between volume changes of sclerotin was established, and scientific bases were provided for introducing the bionic topology optimization method to the remodeling process. The experimental results showed that the self-repairing of the each layer sclerotin of the young rabbits was faster than that of the adult ones under the same condition. In addition, the volume always changes contrarily between the spongy bone and enamel bone during the self-repairing process of bone defect.