The Effects of Acetabular Shell Deformation and Liner Thickness on Frictional Torque in Ultrahigh-Molecular-Weight Polyethylene Acetabular Bearings

Schmidig, Gregg; Patel, Amisha; Liepins, Imants; Thakore, Mayur; Markel, David C.

doi:10.1016/j.arth.2009.03.020

Cited by 24 publications

(30 citation statements)

References 35 publications

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“…Schmidig et al [14] observed higher magnitudes of deformation in the polyethylene liner than in the shell in which they were inserted. Because maximal deformation occurs at the periphery of the cup, this change could potentially lead to adverse consequences with respect to the peripheral locking mechanisms in modular cups.…”

Section: Discussionmentioning

confidence: 98%

“…Recent studies have begun to examine the effect of polyethylene liner deformation in regard to frictional torque, liner fracture, and volumetric wear in foam block and finite element analyses [8,11,14]. Schmidig et al [14] observed higher magnitudes of deformation in the polyethylene liner than in the shell in which they were inserted.…”

Section: Discussionmentioning

confidence: 99%

“…However, with stress relaxation and diminished deformation of the polyethylene liner over time, reduced effect on fracture and wear would be expected. Likewise, the negative clinical impact of this polyethylene deformation may be ameliorated through modern polyethylene processing techniques [14]. It is important to note these potential adverse consequences of liner deformation have yet to be demonstrated clinically.…”

Section: Discussionmentioning

confidence: 99%

“…Clinical and cadaveric investigations have described component pinching between the ischial and ilial columns after press-fit implantation of thin-walled acetabular cups [5,16,17], resulting in deformation of the acetabular cup in underreamed specimens. This deformation could be accompanied by increased micromotion at the bone-implant interface or lead to an increase in wear due to induced changes in component sphericity, degradation of fluid-film lubrication, or induced equatorial contact [5,6,8,11,14,17].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Acetabular Cup Design Influences Deformational Response in Total Hip Arthroplasty

Meding

Small

Jones³

et al. 2013

Clinical Orthopaedics &Amp; Related Research

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Background Press-fit acetabular components are susceptible to deformation in an underreamed socket, with excessive deformation of metal-on-metal (MOM) components potentially leading to increased torsional friction and micromotion. Specifically, however, it remains unclear how cup diameter, design, and time from implantation affect shell deformation. Questions/purposes We asked whether (1) changes in component geometry and material altered maximum shell deformation and (2) time-dependent deformational relaxation processes occurred. Methods Diametral deformation was quantified after press-fit implantation of metal shells into a previously validated polyurethane model. Experimental groups (n = 6-8) consisted of 48-, 54-, 60-, and 66-mm MOM cups of 6-mm wall thickness, 58-mm cups of 10-mm wall thickness, and CoCrMo and Ti6Al4V 58-mm modular cups. Results Greater cup diameter, thinner wall construction, and Ti6Al4V modular designs generated conditions for maximum shell deformation ranging from 0.047 to 0.267 mm. Relaxation (18%-32%) was observed 120 hours postimplantation in thin-walled and modular designs. ConclusionsOur findings demonstrate a reduction of shell deformation over time and suggest, under physiologic loading, early component deformation varies with design. Clinical Relevance Component deformation should be a design consideration regardless of bearing surface. Designs neglecting to adequately address deformational changes in vivo could be susceptible to diminished cup survival, increased wear, and premature revision.

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Section: Discussionmentioning

confidence: 98%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Acetabular Cup Design Influences Deformational Response in Total Hip Arthroplasty

Meding

Small

Jones³

et al. 2013

Clinical Orthopaedics &Amp; Related Research

View full text Add to dashboard Cite

show abstract

“…This acetabular model was designed to replicate the structural properties observed around the acetabulum, which comprised compressive forces anteriorly and posteriorly from the acetabular columns and non-supportive areas superiorly and inferiorly caused by the presence of the radiolucent triangle and the acetabular notch, respectively, resulting in a pinching effect. This model was used in a previous study [12] , and others have similarly been used in studies to assess acetabular shell deformation in both THR and hip resurfacing implants [20][21][22] , stress distribution within press-fitted ceramic liners [23] , and cup turn-out due to joint frictional moments [24] .…”

Section: Methodsmentioning

confidence: 99%

The effect of dynamic hip motion on the micromotion of press-fit acetabular cups in six degrees of freedom

Crosnier

Keogh

Miles

2016

Medical Engineering & Physics

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The hip joint is subjected to cyclic loading and motion during activities of daily living and this can induce micromotions at the bone-implant interface of cementless total hip replacements. Initial stability has been identified as a crucial factor to achieve osseointegration and long-term survival. Whilst fixation of femoral stems achieves good clinical results, the fixation of acetabular components remains a challenge. In vitro methods assessing cup stability keep the hip joint in a fixed position, overlooking the effect of hip motion. The effect of hip motion on cup micromotion using a hip motion simulator replicating hip flexion-extension and a six degrees of freedom measurement system was investigated. The results show an increase in cup micromotion under dynamic hip motion compared to Static Flexion. This highlights the need to incorporate hip motion and measure all degrees of freedom when assessing cup micromotion. In addition, comparison of two press-fit acetabular cups with different surface coatings suggested similar stability between the two cups. This new method provides a basis for a more representative protocol for future pre-clinical evaluation of different cup designs.

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Fabrication of Polyurethane‐Based Composites Used in Water‐Lubricated Bearings

Wang

Yang

et al. 2014

Adv Polym Technol

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The preparation of a new antiwear composites based on polyurethane (PU) elastomer blended and modified with ultra-high molecular weight polyethylene (UHMWPE) has been described. The performance of PU-based composites (PUC) with different proportions of UHMWPE micropowder was demonstrated with mechanical testing, thermal gravimetric analysis, scanning electron microscopy, and friction and wear testing. Compared with the single PU elastomeric material, the composites showed excellent mechanical properties (including tensile strength, break elongation, and flexible modulus), thermal stability, extremely good wear resistance, and low coefficient of friction, especially in water. PUC fabricated in this study is a kind of typical wear-resistant material, which is especially suitable for water-lubricated bearings widely used in metallurgy, mining, hydraulic engineering, and other harsh working conditions. C

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The Effects of Acetabular Shell Deformation and Liner Thickness on Frictional Torque in Ultrahigh-Molecular-Weight Polyethylene Acetabular Bearings

Cited by 24 publications

References 35 publications

Acetabular Cup Design Influences Deformational Response in Total Hip Arthroplasty

Acetabular Cup Design Influences Deformational Response in Total Hip Arthroplasty

The effect of dynamic hip motion on the micromotion of press-fit acetabular cups in six degrees of freedom

Fabrication of Polyurethane‐Based Composites Used in Water‐Lubricated Bearings

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