The work is dedicated to quantify the loss of bone mass prosthetic hip as a result of growth and porosity dense demineralization of bone tissue surrounding the prosthesis stem. The first is the balance equation of bone mass loss prosthetic hip caused by mechanical factors, and given separate assessment of the contributions of these factors to the overall balance of the observed bone loss over a six-year period of operation of the prosthesis. The increase of porosity is investigated with the help of the author’s two-level model adaptation poroelasticity in a sample of bone prosthetic hip. To assess bone loss due to demineralization using the known experimental data. It is found that the 6.5 year duration of operation of the prosthesis porosity increases 4 times, which reduces the effective density of the bone tissue by an amount less than 0.135 g / cm3. Size reduction of the mineral content in the proximal part of the prosthetic hip after 6.5 years of use of the prosthesis is known and reaches 47%, which corresponds to an effective reduction in bone density to 0.067 g / cm3, i.e. 33% of the total mass lost per unit volume of the matrix of bone tissue.