Acta Ortopédica Mexicana

Domínguez-Hernández VM, Ramos LVH, Feria RCV, Urriolagoitia CG, Hernández GLH
Mechanical effects of cement thickness around femoral component in Charnley prosthesis. A biomechanical analysis by the finite element method
Acta Ortop Mex 2000; 14 (6)

Language: Español
References: 18
Page: 443-448
PDF: 77.47 Kb.

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ABSTRACT

Stress and strain fields were analyzed on femoral component of a Charnley hip prosthesis, when physiological loads were applied. Bidimensional geometry of femur was determined by plain X-rays and its behavior was studied when loads corresponding to stance phase of gait were applied. Finite element method, and Ansys version 5.3 (Ansys, Inc., Houston PA, U.S.A.) were used. During analysis, three different materials were considered: trabecular bone, cortical bone corresponding to the hollow part of bone and cortical bone corresponding to the medial and lateral cortex of femur. After that, prosthesis size was chosen to fit our modeled bone and it was inserted on bidimensional femur model. In the same fashion, six cement layer thickness are developed, varying from one to six centimeters. It is desired that stress levels in bone be similar to those found in intact femur, meanwhile lower stress levels are preferable for inert materials such prosthesis as and cement. From six different layer thickness evaluated, a three millimeters cap addresses lower stress levels between prosthesis and cement, meanwhile trabecular bone presents closest stress levels to those corresponding to intact femur. For cortical bone, best results were obtained when cement was 4 millimeters thick. Based upon the present studio we recommend cement mantle thickness between three and four millimeters.


Key words: prosthesis, cement, finite element, biomechanics, hip, femur, analysis.


REFERENCES

  1. Andriacchi TP, Galante JO, Belytschko TB, Hampton S: A stress analysis of the femoral stem in total hip prosthesis. J Bone Joint Surg 1976; 58A: 618-24.

  2. Blacker G, Charnley J: Long-term study of changes in the upper femur after low-friction arthroplasty, Internal Publication No 62, Centre for Hip Surgery, Wrightinton Hospital, 1976.

  3. Brekelmans WAM, Poort HW, Slooff TJ: A new method to analyze the mechanical behavior of skeletal parts. Acta Orthop Scand 1972; 43: 301-17.

  4. Buckwalter JA, Glimcher MJ, Cooper RR, Recker R: Bone biology. Part II: Formation modeling, remodeling, and regulation of cell function. J Bone Joint Surgery 1995; 77A: 1276-89.

  5. Ebramzadeh E, Sarmiento A, McKellop HA, Llinas A, Gogan W: The cement mantle in total hip arthroplasty. Analysis of long-term radiograph results. J Bone Joint Surg 1994; 76A: 77-87.

  6. Huiskes R, Verdonschot N, Niubrant B: Migration, stem shape, and surface finish in cemented total hip arthroplasty. Clin Orthop 1998; 355: 103-12.

  7. Jasty M, Maloney WJ, Bragdon CR, Haire T, Harris WH: Histomorphological studies of the long-term skeletal responses to well fixed cemented femoral components. J Bone Joint Surg 1990; 72A: 1220-9.

  8. Kang YK, Park HC, Youm Y, Lee IK, Ahn MH, Ihn JC: Three dimensional shape reconstruction and finite element analysis of femur before and after the cementless type of total hip replacement. J Biomed Eng 1993; 15: 497-504.

  9. Keyak JH, Fourkas MG, Meagher JM, Skinner HB: Validation of an automated method of three-dimensional finite element modeling of bone. J Biomed Eng 1993; 15: 505-9.

  10. Keyak JH, Rossi SA: Estimation of femoral fracture load using finite element models: An examination of stress-and strain-based failure theories. Trans 44th Annual Meeting Orthop Res Soc 1998: 956.

  11. Kim BS, Mann KA: A thin cement mantle decrease fatigue life of cemented femoral hip components. Trans 45th Annual Meeting Orthop Res Soc 1999: 880.

  12. Kwak BM, Lim OK, Kim YY, Rim K: An investigation of the effect of cement thickness on an implant by finite element stress analysis. Int Orthop 1979; 2: 315-19.

  13. Mann KA, Bartel DL, Ayers DC: Influence of stem geometry on mechanics of cemented femoral hip components with proximal bond. Trans 43rd Annual Meeting Orthop Res Soc 1997: 840.

  14. Mann KA, Bartel DL, Wright TM, Burstein AH: Coulomb frictional interfaces in modeling cemented total hip replacements: A more realistic model. J Biomech 1995; 28(9): 1067-78.

  15. McNamara BP, Cristofolini L, Toni A, Taylor D: Relationship between bone-prosthesis bonding and load transfer in total hip reconstruction. J Biomech 1997; 30(6): 621-30.

  16. Namba RS, Keyak JH, Kim AS, Vu LP, Skinner HB: Cementless implant composition and femoral stress. Clin Orthop 1998; 347: 261-7.

  17. Rohlmann A, Mössner U, Bergmann G, Koelbel R: Finite-element analysis and experimental investigation with hip endoprosthesis. J Biomech 1983; 16: 727-42.

  18. Van Rietbergen B, Müller R, Ulrich D, Rüegsegger P, Huiskes R: Quantitative assessment of tissue loading in proximal femur, using a full scale microstructural FE-model. Trans 43rd Annual Meeting Orthop Res Soc 1997: 62.