Individual chronobiological control of the reproducibility error by using the dexa method for evaluation of mineral density in the periprosthetic zone of patients after total hip arthroplasty

Purpose Using chronobiological methodology and on the basis of individual analysis, to determine the character of changes in the reproducibility error (RE) of double-energy X-ray absorptiometry (DEXA) by assessment of the projection bone mineral density in the Gruen zones in patients after total hip arthroplasty in the early postoperative period. Materials and methods Eight men and two women were examined. Results RE value was changed in oscillation manner. It was hypothesized that it is caused by tremor. On this basis, a theoretical physical model was proposed which considers the mechanisms of X-ray radiation attenuation by passing through bone tissue. According to the model, the tremor changes the length of X-ray path in the bone tissue. The fact that bone structure is characterized by parts with high and low atom density was taken into account in the model. It is especially strongly manifested in the areas of the trabecular bone. Theoretical modeling allowed us to suggest the physical mechanisms of tremor effect on X-ray radiation passing through bone structures as well as to demonstrate the dependence of the study results on tremor-related spatial vibrations of bone structures Conclusions These findings should be taken into account when investigating the projection mineral density of bone tissue in the periprosthetic zone after hip arthroplasty.