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PMMA third-body wear after unicondylar knee arthroplasty decuples the UHMWPE wear particle generation in vitro.

Paulus AC, Franke M, Kraxenberger M, Schröder C, Jansson V, Utzschneider S - Biomed Res Int (2015)

Bottom Line: The particles of all groups were similar in size and shape.The addition of bone or PMMA particles in terms of a third-body wear results in no change of particle size and morphology.PMMA third-bodies generated tenfold elevated particle numbers.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopedic Surgery, University Hospital of Munich (LMU), Campus Großhadern, Marchioninistraße 15, 81377 Munich, Germany.

ABSTRACT

Introduction: Overlooked polymethylmethacrylate after unicondylar knee arthroplasty can be a potential problem, since this might influence the generated wear particle size and morphology. The aim of this study was the analysis of polyethylene wear in a knee wear simulator for changes in size, morphology, and particle number after the addition of third-bodies.

Material and methods: Fixed bearing unicondylar knee prostheses (UKA) were tested in a knee simulator for 5.0 million cycles. Following bone particles were added for 1.5 million cycles, followed by 1.5 million cycles with PMMA particles. A particle analysis by scanning electron microscopy of the lubricant after the cycles was performed. Size and morphology of the generated wear were characterized. Further, the number of particles per 1 million cycles was calculated for each group.

Results: The particles of all groups were similar in size and shape. The number of particles in the PMMA group showed 10-fold higher values than in the bone and control group (PMMA: 10.251 × 10(12); bone: 1.145 × 10(12); control: 1.804 × 10(12)).

Conclusion: The addition of bone or PMMA particles in terms of a third-body wear results in no change of particle size and morphology. PMMA third-bodies generated tenfold elevated particle numbers. This could favor an early aseptic loosening.

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The change of the polyethylene wear particle number in the progress of the simulator tests, respectively after the addition of the third-body wear.
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fig5: The change of the polyethylene wear particle number in the progress of the simulator tests, respectively after the addition of the third-body wear.

Mentions: We found differing particle numbers for each group. First, a difference between the running in and the steady state phase was found. In the running in phase 5.126 × 1012 particles were calculated per 1 million cycles. In the steady state phase the particle number decreased to 1.804 × 10 1012. Interestingly, the addition of bone particles did not lead to an increase of the particle number (1.146 × 1012), whereas the added PMMA particles in the PMMA particle group decupled the polyethylene wear particle number (10.252 × 1012; Figure 5). The huge number of accumulating particles can already be suggested in Figures 3(b) and 3(e).


PMMA third-body wear after unicondylar knee arthroplasty decuples the UHMWPE wear particle generation in vitro.

Paulus AC, Franke M, Kraxenberger M, Schröder C, Jansson V, Utzschneider S - Biomed Res Int (2015)

The change of the polyethylene wear particle number in the progress of the simulator tests, respectively after the addition of the third-body wear.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4383432&req=5

fig5: The change of the polyethylene wear particle number in the progress of the simulator tests, respectively after the addition of the third-body wear.
Mentions: We found differing particle numbers for each group. First, a difference between the running in and the steady state phase was found. In the running in phase 5.126 × 1012 particles were calculated per 1 million cycles. In the steady state phase the particle number decreased to 1.804 × 10 1012. Interestingly, the addition of bone particles did not lead to an increase of the particle number (1.146 × 1012), whereas the added PMMA particles in the PMMA particle group decupled the polyethylene wear particle number (10.252 × 1012; Figure 5). The huge number of accumulating particles can already be suggested in Figures 3(b) and 3(e).

Bottom Line: The particles of all groups were similar in size and shape.The addition of bone or PMMA particles in terms of a third-body wear results in no change of particle size and morphology.PMMA third-bodies generated tenfold elevated particle numbers.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopedic Surgery, University Hospital of Munich (LMU), Campus Großhadern, Marchioninistraße 15, 81377 Munich, Germany.

ABSTRACT

Introduction: Overlooked polymethylmethacrylate after unicondylar knee arthroplasty can be a potential problem, since this might influence the generated wear particle size and morphology. The aim of this study was the analysis of polyethylene wear in a knee wear simulator for changes in size, morphology, and particle number after the addition of third-bodies.

Material and methods: Fixed bearing unicondylar knee prostheses (UKA) were tested in a knee simulator for 5.0 million cycles. Following bone particles were added for 1.5 million cycles, followed by 1.5 million cycles with PMMA particles. A particle analysis by scanning electron microscopy of the lubricant after the cycles was performed. Size and morphology of the generated wear were characterized. Further, the number of particles per 1 million cycles was calculated for each group.

Results: The particles of all groups were similar in size and shape. The number of particles in the PMMA group showed 10-fold higher values than in the bone and control group (PMMA: 10.251 × 10(12); bone: 1.145 × 10(12); control: 1.804 × 10(12)).

Conclusion: The addition of bone or PMMA particles in terms of a third-body wear results in no change of particle size and morphology. PMMA third-bodies generated tenfold elevated particle numbers. This could favor an early aseptic loosening.

Show MeSH
Related in: MedlinePlus