Fracture Behavior of the Cement Mantle of Reconstructed Acetabulum in the Presence of a Microcrack Emanating from a Microvoid

Abstract

In this work, the fin ite element method is used to analyze the behavior of the crack emanating fro m a microvoid in acetabular cement mantle by co mputing the stress intensity factor. A simple 2D mu ltilayer model developed by Benbarek et al.[1] to reproduce the stress distributions in the cement mantle has been used. To provide the place of birth of the crac k, the stress distribution around the microvoid is determined in several positions for three different loads. The effect of axial an d radial d isplacement of the microvoid in the cement is highlighted. The results indicate that the stress distribution , xx  yy  and xy  induced in the cement around the microvoid are not ho mogeneous and this, whatever its position. In addit ion, there is a large birth risk of cracks in several radial directions depending on the position of the microvoid in the cement mantle. The crack can be triggered in several d irect ions in mode I or mode II, while the mixed mode is dominant. The K I and K II SIF varies according to the position of the microcrack and the microvoid in the cement. They increase proportionally with the increase of the weight of the patient. It should be noted that the K I SIF are t wo t imes higher than the SIF K II. The maxima of the K I SIF are obtained for the position of the microvoid α = 100° and θ = 45° of the microcrack and the risk of the propagation of the microcrack is very important for this orientation.

Study of an Additional Layer of Cement Mantle Hip Joints for Reducing Cracks

“…However, the maximum von Mises stress for all simulated materials were still within the elastic limit over all thickness variations. The tensile strength of the PMMA material is approximately 25 MPa [17,18,19]. The von Mises stress results in this study confirms the study of stress [7] and strain [1] characteristics.…”

“…Table 1 summarizes the material properties from literature that were used for the components of the hip prosthesis simulation. According to Anderson et al [16], Sahli et al [17], and Ouinas et al [18], cortical bone has a modulus of elasticity of 17,000 MPa and Poisson’s ratio of 0.3. The cement mantle of polymethyl methacrylate (PMMA) has a modulus of elasticity ranging from 2000 to 2300 MPa and Poisson’s ratio of 0.3 according to [17,18], and Achour et al [19].…”

“…According to Anderson et al [16], Sahli et al [17], and Ouinas et al [18], cortical bone has a modulus of elasticity of 17,000 MPa and Poisson’s ratio of 0.3. The cement mantle of polymethyl methacrylate (PMMA) has a modulus of elasticity ranging from 2000 to 2300 MPa and Poisson’s ratio of 0.3 according to [17,18], and Achour et al [19]. The ultra–high–molecular–weight polyethylene (UHMWPE) liner as used by [18,19], and Eichmiller et al [20], has an elasticity modulus of 690 to 945 MPa and Poisson’s ratio of 0.45.…”

“…The cement mantle of polymethyl methacrylate (PMMA) has a modulus of elasticity ranging from 2000 to 2300 MPa and Poisson’s ratio of 0.3 according to [17,18], and Achour et al [19]. The ultra–high–molecular–weight polyethylene (UHMWPE) liner as used by [18,19], and Eichmiller et al [20], has an elasticity modulus of 690 to 945 MPa and Poisson’s ratio of 0.45. The ball was 316 L stainless steel as used by Yildiz et al [21], with a modulus of elasticity of 193,000 MPa and Poisson’s ratio of 0.3.…”

Finite Element analysis of stress state in the cement of total hip prosthesis with elastomeric stress barrier

“…A numerical study with four different stem shapes of varying curvatures for hip prosthesis was conducted by Senalp et al [16] to determine the fatigue endurance of cemented implant and to reduce sliding of the implant in the bonecement. The effect of the position and orientation of a crack in the cement mantle under various loads using the finite element method has been studied [17][18][19]. In this work, a three dimensional finite element method was employed to analyze both conventional and proposed prosthesis.…”