Peculiarities of stress-strain state of the conical stem of the hip endoprosthesis in different types of its fixation


  • Oleg Loskutov



arthroplasty, hip joint, femoral stem, femur, modeling, stress state, finite element method


Objective: To study stress state of the femur and the conical femoral stem of the hip endoprosthesis KS «ORTEN» in differ­ent types of fixation and functional loadings.

Methods: The finite element modeling with using the software complex «ANSYS» and computational model «bone – implant».

Results: it was found that regardless of level of fixation maximal tensile stresses arise on the lateral surface of the femoral stem and bone, and squeezing ones were on the medial surface. In cases of diaphyseal fixation type we determined maximal stresses in the endoprosthesis when the surface area of contact with the bone is too small (less than 40 %). Increasing the contact area of the femoral stem with the bone increases the rigidity of the system «bone - implant» and reduces tensile and compressive stresses in the body of the femoral stem. In case of diaphyseal fixation there can occur stress concen­tration in the distal femur leading to the risk of stress-shielding effect and instability of the implant. In case of metaphyseal fixation we revealed a uniform distribution of stress on the bone which eliminates excessive concentration of mechanical stress. Optimal stress distribution in the femur may be achieved in case when the contact area of the femoral stem with the bone is 50 % or more. Conclusion: The value of the maximum stresses in the conical femoral stem of KS «ORTEN» with metaphyseal-diaphyseal type of fixation was 34 ÷ 140 MPa, and for the femur was 5,8 ÷ 7,15 MPa. For all types of fixation of the endoprosthesis maximal tensile stresses were found on the lateral surface of its stem and squeezing ones on the medial. In case of diaphyseal fixation of the conical femur stem stress concentration occurs in the distal femur which increases the risk of stress-shielding effect and instability of the endoprosthesis. In cases of metaphyseal and metaphyseal-diaphyseal fixation stresses distribute evenly ensuring continued functioning of the endoprosthesis.


Loskutov A. Ye. Hip replacement: monography / edited by . prof. А. Ye. Loskutov. — Dnipropetrovsk: Lira, 2010. — 344 p.

Bone grafting in cementless total hip replacement for congeni¬tal dysplasia of the hip / X. Dai, H. Omori, M. Ando [et al.] // Int. Orthop. — 2000. — Vol. 24. — P. 260–263.

Is there evidence for a superior method of socket fixation in total hip arthroplasty? A systematic review / D. Pakvis, G. van Hellemondt, E. de Visser [et al.] // Int. Orthop. — 2011. — Vol. 35. — P. 1109–1118.

The new arthritic patient and nonarthroplasty treatment op¬tions / M. A. Kelly, D. F. Dalury, R. H. Kim, D. Backstein // J. Bone Joint Surg. — 2009. — Vol. 91, Suppl. 5. — P. 40–42.

Biomechanical and mathematical justification of development preconditions of aseptic loosening after uncemented total hip replacement / G. V. Gayko, V. M. Pidgayetskiy, O. M. Sulyma, O. V. Chkalov [et. al.] // Materials of scientific-practical conference with international participation [«Actual problems of joint replacement»]. — Vinnitsa, 2008. — P. 23–24.

Oleynik A. E. Biomechanical analyze of hip endoprosthesis femoral component construction «ORTEN» / A. E. Oleynik, V. L. Krasovsky, O. A. Loskutov // Orthopedics, traumatology and prostetics. — 2009. — № 1. — P. 17–25; doi: 10.15674/0030-59872009126-29.

Prohorenko V. M. Primary and revision hip replacement / V. M. Prohorenko. — Novosibirsk: ANO «Clinic NIITO», 2007. — 348 p.

Pidgayska О. О. Stem choice before uncemented hip replacement justification: author's abstract of dissertation ... Ph. D.: spec. 14.01.21 «Traumatology and orthopeadics» / О. О. Pidgayska. — Kharkiv, 2014. — 24 p.

Zenkevych О. The method of finite elements in technician / О. Zenkevych. — М.: Myr, 1975. — 542 p.

Hip contact forces and gait patterns from routine activities / G. Bergmann, G. Deuretzbacher, M. Heller [et al.] // J. Biomechanics. — 2001. — Vol. 34. — P. 859–871.