Advances in simulator testing of orthopaedic joint prostheses

Stewart, Todd; Williams, Sophie; Tipper, Joanne L.; Ingham, Eileen; Mh, Stone; Fisher, John

doi:10.1016/s0167-8922(03)80141-4

Cited by 6 publications

(6 citation statements)

References 13 publications

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“…From experimental studies of microseparation in the hip simulator, Fisher's group [26,27,31] showed the microseparation form of edge loading used in their experimental model accelerated wear of the overall articulation with both MOM and COC articulations. Importantly, the results of similar studies using MOP articulations were exactly the opposite.…”

Section: Discussionmentioning

confidence: 99%

“…The relationship between microseparation, edge loading, and wear across the joint was evaluated experimentally by Fisher's group [26,27,31] using a model system that simulated microseparation in a modified hip simulator. Their model showed microseparation produced both edge wear and accelerated general wear in COC articulations, as well as in MOM joints using the same type of model [14].…”

Section: Evidence For Edge Loading In Mop Thamentioning

confidence: 99%

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Edge Loading Has a Paradoxical Effect on Wear in Metal-on-Polyethylene Total Hip Arthroplasties

Harris

2012

Clinical Orthopaedics &Amp; Related Research

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Background Edge wear is an adverse factor that can negatively impact certain THAs. In some metal-on-metal THAs, it can lead to adverse tissue reactions including aseptic lymphocytic vasculitis-associated lesions and even to pseudotumor formation. In some ceramic-on-ceramic THAs, it can lead to squeaking and/or stripe wear. Edge wear in metal-on-metal and ceramic-on-ceramic THAs can also be associated with accelerated wear across the articulation of these joints. Questions/purposes I asked: Does edge wear occur in metal-on-polyethylene (MOP) articulations? And if so, does it increase joint wear? Methods I examined the evidence in the literature for edge wear occurring in MOP THA and then assessed the evidence in the literature for data supporting the concept that edge wear in MOP hips could accelerate wear across the articulation over time.

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Section: Discussionmentioning

confidence: 99%

Section: Evidence For Edge Loading In Mop Thamentioning

confidence: 99%

Edge Loading Has a Paradoxical Effect on Wear in Metal-on-Polyethylene Total Hip Arthroplasties

Harris

2012

Clinical Orthopaedics &Amp; Related Research

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“…Full details of the wear test and procedure can be found elsewhere. 18,19 The nominal diameter of the prosthesis was 28 mm. From these tests, a total of 18 Biolox V R forte alumina acetabular cups and 13 Biolox V R forte alumina femoral heads were selected for study on the basis that they exhibited some evidence of wear and were known to be completely free from damage on removal from the test rig and subsequent cleaning.…”

Section: Methodsmentioning

confidence: 99%

Characterization of worn alumina hip replacement prostheses

et al. 2011

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Alumina hip replacement prostheses have been analyzed following in vitro simulated microseparation. The worn surfaces of the alumina acetabular cup and femoral head were investigated using scanning electron microscopy (SEM) and atomic force microscopy (AFM) which identified four different wear zones. Focused ion beam (FIB) cross-sectioning was used to section the worn surface and produce 3D reconstructions of the subsurface damage. This showed that the subsurface fracture was predominantly intergranular, with occasional intragranular fracture. Significantly, in all cases, fracture was restricted to the outer layer of grains. The wear mechanisms leading to the generation of the stripe wear region on the worn alumina hip prostheses are proposed and microseparation is believed to play a critical role.

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“…1 This discrepancy is related to edge loading that can occur clinically due to lateralization (microseparation) of the femoral head relative to the acetabular cup, causing a localized increase in stress and wear. Although a number of experimental wear simulator studies have been conducted that reproduce edge loading under microseparation conditions, the general tribological mechanism under this adverse condition is unclear.…”

mentioning

confidence: 99%

In vitro investigation of friction under edge‐loading conditions for ceramic‐on‐ceramic total hip prosthesis

Sariali

Stewart

Jin

et al. 2010

Journal Orthopaedic Research

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Edge-loading generates higher wear rates in ceramic-on-ceramic total hip prosthesis (THP). To investigate the friction coefficient (FC) in these conditions, three alumina ceramic (Biolox Forte) 32 mm-diameter components were tested using a hip friction simulator. The cup was positioned with a 758 abduction angle to achieve edge-loading conditions. The motion was first applied along the edge and then across the edge of the cup. First, tests were conducted under lubricated conditions with 25% bovine serum. Next, to simulate an extremely high contact pressure, the tests were run with the addition of a third body alumina ceramic chip inserted between the edge of the cup and the head. Engineering blue was used to analyze the contact area. Reference values were determined using a 08 cup abduction angle. Edge loading was achieved. The FC increased by three-to sixfold when the motion was applied along the edge, and by 70% when the motion was applied across the edge. However, the FC value was still low (about 0.1), which is similar to metal-on-metal THP. With the third body alumina ceramic particle inserted, the FC was 26 times higher than in the ideal conditions and intermittent squeaking occurred. High cup abduction angles may generate edge-loading and an increase in the friction coefficient for ceramic THP. Keywords: friction coefficient; ceramic; hip prosthesis; edge loading; squeaking Ceramic-on-ceramic retrievals from total hip prostheses (THP) show higher wear rates than those predicted on simulators under normal conditions. 1 This discrepancy is related to edge loading that can occur clinically due to lateralization (microseparation) of the femoral head relative to the acetabular cup, causing a localized increase in stress and wear. Although a number of experimental wear simulator studies have been conducted that reproduce edge loading under microseparation conditions, the general tribological mechanism under this adverse condition is unclear. Friction levels, for example, have not been reported under these edgeloading conditions. We hypothesized that the friction coefficient (FC) increases under edge-loading conditions. A study to test such an hypothesis is important as it may assist in the understanding of clinical hip noises such as squeaking. 2,3 In addition, FC values are needed to develop computational models of contact mechanics and wear prediction under edge loading conditions, which can help improve implant design. Our goals were to determine the FC under edge loading for alumina ceramic-on-ceramic THP and to investigate the effect of the addition of alumina debris on the FC and the generation of squeaking. MATERIALS AND METHODS SpecimensThree Biolox Forte heads and liners were tested on the Leeds PROSIM 1 friction simulator. The components had a diameter of 32 mm, with a radial clearance of 30 mm. All specimens were manufactured by Ceramtec (Plochingen, Germany). Before testing, specimens were cleaned with a washing-up liquid, rinsed in water, and then ultrasonically cleaned in an isopropanol ...

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Advances in simulator testing of orthopaedic joint prostheses

Cited by 6 publications

References 13 publications

Edge Loading Has a Paradoxical Effect on Wear in Metal-on-Polyethylene Total Hip Arthroplasties

Edge Loading Has a Paradoxical Effect on Wear in Metal-on-Polyethylene Total Hip Arthroplasties

Characterization of worn alumina hip replacement prostheses

In vitro investigation of friction under edge‐loading conditions for ceramic‐on‐ceramic total hip prosthesis

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