Ceramic Femoral Heads for Total Hip Arthroplasty

Willmann, Gero

doi:10.1002/(sici)1527-2648(200003)2:3<114::aid-adem114>3.0.co;2-p

Cited by 48 publications

(11 citation statements)

References 6 publications

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“…As a related matter, the size of a given microflaw will determine the degree of associated reduction of the material's mechanical properties. The assumed microflaws posited in the present study represent a mechanical decrement approaching alumina's limiting (initial) stress intensity factor, K I0 [39]. Proof-testing of ceramic implants was initiated to identify the presence of such microflaws immediately after manufacture; therefore, the likelihood is low of implanting a ceramic liner with a microflaw of similar magnitude as represented in the present study.…”

Section: Discussionmentioning

confidence: 59%

“…The vast majority of the fractures simulated in this investigation occurred for microflawed alumina, in which subcritical microfractures were assumed to be homogenously dispersed throughout the entire liner. Although microscopic imperfections are ubiquitous in modern ceramics [15,39], the probability of such an imperfection being just below critical size and existing precisely at the location of greatest tensile stress (as simulated in the present study) is certainly rather low. As a related matter, the size of a given microflaw will determine the degree of associated reduction of the material's mechanical properties.…”

Section: Discussionmentioning

confidence: 99%

“…The joint contact loads for different BMIs were linearly scaled from the baseline BMI (26.5 kg/m 2 ) of the test subjects. Because microscopic imperfections (which are ubiquitous in sintered ceramic materials [15,39]) decrease the tensile stresses otherwise necessary for fracture, material properties of alumina were varied to simulate liners both with and without microflaws.…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Do Obesity and/or Stripe Wear Increase Ceramic Liner Fracture Risk? An XFEM Analysis

Elkins

Pedersen

Callaghan

et al. 2013

Clinical Orthopaedics &Amp; Related Research

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Background Hypothesized risk factors for fracture of ceramic liners include impingement, edge-loading, and cup malpositioning. These risk factors are similar to those for generation of stripe wear. However, it is unclear whether the biomechanical conditions contributing to stripe wear generation also increase the risk for ceramic liner fracture Questions/purposes We asked whether (1) head stripe wear propensity; and (2) cup orientation would correlate with alumina liner fracture risk for instances of normal and elevated body weight. Methods An eXtended Finite Element Method (XFEM) model was developed to investigate these mechanisms. Liner fracture risk for 36-mm alumina bearings was studied by simulating two fracture-prone motions: stooping and squatting. Twenty-five distinct cup orientations were considered with variants of both acetabular inclination and anteversion. Four separate body mass indices were considered: normal (25 kg/m 2 ) and three levels of obesity (33, 42, and 50 kg/ m 2 ). Material properties were modified to simulate alumina with and without the presence of dispersed microflaws. The model was validated by corroboration with two previously published ceramic liner fracture studies. Results Of 200 XFEM simulations with flaw-free alumina, fracture occurred in eight instances, all of them involving obesity. Each of these occurred with cups in B 37°inclina-tion and in 0°anteversion. For 200 corresponding simulations with microflawed alumina, fracture propensity was greatest for cups with higher (edge loading-associated) scraping wear. Fracture risk was greatest for cups with lower inclination (average 42°for fractured cases versus 48°for nonfractured cases) and lower anteversion (9°versus 20°). Conclusions Fracture propensity for 36-mm liners was elevated for cups with decreased anteversion and/or inclination and under conditions of patient obesity. Clinical Relevance Factors causing stripe wear, including obesity and cup malpositioning, also involve increased risk of ceramic liner fracture and merit heightened concern.

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Section: Discussionmentioning

confidence: 59%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Do Obesity and/or Stripe Wear Increase Ceramic Liner Fracture Risk? An XFEM Analysis

Elkins

Pedersen

Callaghan

et al. 2013

Clinical Orthopaedics &Amp; Related Research

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“…In any case, the threshold K I0 represents the key parameter as far as durability is concerned 44 (as for orthopedic implants, which must survive in vivo for more than 10 years). From the well-known stress-intensity factor equation:…”

Section: Figure 7 Andmentioning

confidence: 99%

Slow‐Crack‐Growth Behavior of Zirconia‐Toughened Alumina Ceramics Processed by Different Methods

Aza

Chevalier

Fantozzi

et al. 2003

Journal of the American Ceramic Society

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A study of slow-crack propagation in zirconia-toughened alumina (ZTA) ceramics is presented. Different ZTA composites, using either unstabilized or yttria-stabilized zirconia, have been tested. The materials were prepared in the range 0 -15 vol% ZrO 2 , using two processing methods: powder mixing and a modified colloidal route. Crack propagation tests have been conducted for crack velocities from 10 ؊12 to 10 ؊2 m/s by means of a double-torsion method. The influence of the processing conditions and compositions on the microstructures and the effect of these microstructures on the slow-crackgrowth behavior have been studied. The option that these composites may offer in terms of the lifetime of ceramic joint prostheses is discussed.

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“…Currently, alumina ceramics, Al 2 O 3 , are widely used for bearing surfaces THR [6]. Their widespread use is based on a combination of good strength, modest fracture toughness, high wear resistance, good biocompatibility and excellent corrosion resistance.…”

Section: Introductionmentioning

confidence: 99%

Crack growth resistance of alumina, zirconia and zirconia toughened alumina ceramics for joint prostheses

et al. 2002

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Mono-phase bio-ceramics (alumina and zirconia) are widely used as femoral heads in total hip replacements (THR) as an alternative to metal devices. Unfortunately, the orthopaedic community reports significant in-vivo failures. Material scientists are already familiar with composites like alumina-zirconia. Since both are biocompatible, this could prove to be a new approach to implants. This paper deals with a new generation of alumina-zirconia nano-composites having a high resistance to crack propagation, and as a consequence may offer the option to improve lifetime and reliability of ceramic joint prostheses. The reliability of the above mentioned three bio-ceramics (alumina, zirconia and zirconia toughened alumina) for THR components is analysed based on the study of their slow crack-growth behaviour. The influence of the processing conditions on the microstructure development, of the zirconia toughened alumina composites and the effect of these microstructures, on its mechanical properties, are discussed. r

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Ceramic Femoral Heads for Total Hip Arthroplasty

Cited by 48 publications

References 6 publications

Do Obesity and/or Stripe Wear Increase Ceramic Liner Fracture Risk? An XFEM Analysis

Do Obesity and/or Stripe Wear Increase Ceramic Liner Fracture Risk? An XFEM Analysis

Slow‐Crack‐Growth Behavior of Zirconia‐Toughened Alumina Ceramics Processed by Different Methods

Crack growth resistance of alumina, zirconia and zirconia toughened alumina ceramics for joint prostheses

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