Ratcheting behavior of adult and juvenile cartilage under rolling load / 中国组织工程研究

BACKGROUND: Domestic and foreign scholars have done a lot of researches on the stress of articular cartilage under different mechanical environments and cyclic compressive loads, but they mainly studied the effect of cartilage under the cyclic compressive load. Studies on the effects of age factor on the mechanical properties of cartilage and studies regarding the properties of cartilage in complex stress environments are not exhaustive. OBJECTIVE: To investigate the effects of different rolling load conditions on the ratcheting behavior of adult and juvenile articular cartilage. METHODS: Adult cartilage and juvenile cartilage were used as experimental objects, and the load was applied by a rolling load device under different experimental conditions (compression: 10%, 20%, 30%; rolling rate: 1.66, 3.44, 6.68 mm/s; defect width: 1, 2,4 mm). At the same time, non-contact digital technology was used to collect the sample during the loading process, and the cyclical pressure was studied by analyzing and processing the image. The ratcheting behavior of adult and juvenile articular cartilage was studied under rolling load. RESULTS AND CONCLUSION: Under rolling load, the ratcheting strain of adult cartilage and juvenile cartilage showed a rapid increase followed by a slow increase tendency with the rolling load. With the increase of compression, the ratcheting strain of adult cartilage and juvenile cartilage increased. At the same amount of compression, the ratcheting strain of juvenile cartilage was greater than that of adult cartilage, and their ratcheting strain gradually decreased from the surface layer to the deep layer along the depth of cartilage. As the rolling rate increased, the ratcheting strain of adult cartilage and juvenile cartilage decreased. The ratcheting strain values and trends of 1 mm microdefect articular cartilage were similar to those of intact articular cartilage. Under the condition of 2,4 mm defect, the ratcheting strain value of the defected cartilage was higher than that of the intact cartilage.

Ratcheting strain and theoretical prediction of articular cartilage under cyclic loading / 医用生物力学

Objective To obtain the ratcheting strain of articular cartilage under different loading conditions, and construct the theoretical model so as to predict the ratcheting strain of cartilage. Methods The fresh articular cartilage obtained from the trochlear of distal femur was used as experimental subject. The ratcheting strain of articular cartilage was tested under cyclic compressive loads by applying the non-contact digital image correlation technique. The theoretical model was constructed to predict the ratcheting strain of articular cartilage with different stress amplitudes and stress rates. The results from predictions were compared with the experimental results. Results The ratcheting strain of cartilage increased rapidly at initial stage and then showed the slower increase with cycles increasing. The ratcheting strain increased with stress amplitude increasing when the stress rate was constant. However, the ratcheting strain decreased with stress rate increasing when the stress amplitude was constant. When the stress rate increased, the ratcheting stain decreased. The prediction results of the established theoretical model were in good agreement with experimental results. Conclusions The ratcheting strain of articular cartilage is proportional to the stress amplitude, and inversely proportional to the stress rate. The established theoretical model can predict the ratcheting strain of articular cartilage and provide guidance for the construction of tissue engineered artificial cartilage.

Ratcheting strain and theoretical prediction of articular cartilage under cyclic loading / 医用生物力学

Objective To obtain the ratcheting strain of articular cartilage under different loading conditions,and construct the theoretical model so as to predict the ratcheting strain of cartilage.Methods The fresh articular cartilage obtained from the trochlear of distal femur was used as experimental subject.The ratcheting strain of articular cartilage was tested under cyclic compressive loads by applying the non-contact digital image correlation technique.The theoretical model was constructed to predict the ratcheting strain of articular cartilage with different stress amplitudes and stress rates.The results from predictions were compared with the experimental results.Results The ratcheting strain of cartilage increased rapidly at initial stage and then showed the slower increase with cycles increasing.The ratcheting strain increased with stress amplitude increasing when the stress rate was constant.However,the ratcheting strain decreased with stress rate increasing when the stress amplitude was constant.When the stress rate increased,the ratcheting stain decreased.The prediction results of the established theoretical model were in good agreement with experimental results.Conclusions The ratcheting strain of articular cartilage is proportional to the stress amplitude,and inversely proportional to the stress rate.The established theoretical model can predict the ratcheting strain of articular cartilage and provide guidance for the construction of tissue engineered artificial cartilage.

Ratcheting strain and theoretical prediction of articular cartilage under cyclic loading / 医用生物力学

Objective To obtain the ratcheting strain of articular cartilage under different loading conditions,and construct the theoretical model so as to predict the ratcheting strain of cartilage.Methods The fresh articular cartilage obtained from the trochlear of distal femur was used as experimental subject.The ratcheting strain of articular cartilage was tested under cyclic compressive loads by applying the non-contact digital image correlation technique.The theoretical model was constructed to predict the ratcheting strain of articular cartilage with different stress amplitudes and stress rates.The results from predictions were compared with the experimental results.Results The ratcheting strain of cartilage increased rapidly at initial stage and then showed the slower increase with cycles increasing.The ratcheting strain increased with stress amplitude increasing when the stress rate was constant.However,the ratcheting strain decreased with stress rate increasing when the stress amplitude was constant.When the stress rate increased,the ratcheting stain decreased.The prediction results of the established theoretical model were in good agreement with experimental results.Conclusions The ratcheting strain of articular cartilage is proportional to the stress amplitude,and inversely proportional to the stress rate.The established theoretical model can predict the ratcheting strain of articular cartilage and provide guidance for the construction of tissue engineered artificial cartilage.

Ratcheting strain and theoretical prediction of articular cartilage under cyclic loading / 医用生物力学

Objective To obtain the ratcheting strain of articular cartilage under different loading conditions,and construct the theoretical model so as to predict the ratcheting strain of cartilage.Methods The fresh articular cartilage obtained from the trochlear of distal femur was used as experimental subject.The ratcheting strain of articular cartilage was tested under cyclic compressive loads by applying the non-contact digital image correlation technique.The theoretical model was constructed to predict the ratcheting strain of articular cartilage with different stress amplitudes and stress rates.The results from predictions were compared with the experimental results.Results The ratcheting strain of cartilage increased rapidly at initial stage and then showed the slower increase with cycles increasing.The ratcheting strain increased with stress amplitude increasing when the stress rate was constant.However,the ratcheting strain decreased with stress rate increasing when the stress amplitude was constant.When the stress rate increased,the ratcheting stain decreased.The prediction results of the established theoretical model were in good agreement with experimental results.Conclusions The ratcheting strain of articular cartilage is proportional to the stress amplitude,and inversely proportional to the stress rate.The established theoretical model can predict the ratcheting strain of articular cartilage and provide guidance for the construction of tissue engineered artificial cartilage.