Correlation of the physicochemical, dimensional and packing characteristics with the wear behavior of metal-on-UHMWPE tribological pairs

ABSTRACT

This manuscript presents preliminary results on the combined effects of physicochemical, dimensional, and packaging characteristics of ultra-high molecular weight polyethylene (UHMWPE) acetabular inserts on the wear rates of metal-on-polyethylene tribological pairs. Wear tests were conducted on tribological pairs from three different manufacturers (A, B, and C), in triplicate for each manufacturer until each pair reached 5 million cycles. Surface finish, dimensional properties, and physicochemical characteristics of the inserts were evaluated and subsequently correlated and discussed based on the measured wear rates. Higher average wear rates were observed for all three tribological pairs from manufacturer B (71.71 ± 10.61 mg per million cycles), which exhibited the largest diametrical clearance between components, higher surface roughness, and a higher oxidation index (0.329 ± 0.027) compared to the other manufacturers. Additionally, samples from manufacturer B with poorer physicochemical properties were stored in packaging lacking an oxygen barrier. Therefore, the study demonstrated that even with a certain level of cross-linking, inadequate sterilization process control and the use of non-oxygen-barrier packaging can lead to higher subsequent wear compared to non-cross-linked material.

Keywords:
UHMWPE; Total hip arthroplasty; Wear rate

1. INTRODUCTION

Total hip arthroplasty (THA) is a common orthopedic procedure performed worldwide [¹]. It involves replacing degenerate joint surfaces with an artificial implant to restore joint biomechanics and achieve primary goals such as pain reduction, improved joint mobility, and gait capacity. This procedure is increasingly recommended for younger, more active patients, driven by rising life expectancy globally [²].

Ultra-high molecular weight polyethylene (UHMWPE) has been a staple material for acetabular cups for over 50 years, owing to its mechanical and tribological properties derived from long, non-radical chains and strong secondary forces [³]. However, wear remains the primary cause of THA failure, significantly impacting long-term performance [⁴]. UHMWPE is susceptible to oxidative degradation, influenced by factors like shelf storage in oxygen-permeable packaging or exposure to oxygen-rich synovial fluid [⁵]. Oxygen acts by breaking molecular chains, reducing molecular weight, and thereby diminishing mechanical and tribological properties [⁶].

As wear resistance declines, contact between the spherical head and acetabular cup induces wear. Despite UHMWPE’s reputation for biocompatibility, this process can release small particles into surrounding tissues. These debris particles trigger the body’s immune response, initiating inflammation [⁷]. Inflammatory responses release mediators that stimulate osteoclastic activity, leading to bone resorption and subsequent osteolysis [⁸]. Given the substantial costs associated with surgery and ongoing concerns about implant performance, there is a critical need to explore new materials and/or designs offering enhanced wear resistance.

In addressing UHMWPE’s susceptibility to oxidative degradation, cross-linked UHMWPE bearings emerged in the 1980s. Gamma irradiation of the bearings creates a more interconnected network that hinders oxygen interaction with molecular chains. However, if gamma irradiation occurs in the presence of oxygen, the open chains produced may interact preferentially with oxygen, compromising bearing performance [⁹]. Gamma irradiation is also used for sterilization, but in an open atmosphere, it can adversely affect the bearings. An alternative sterilization method involves ethylene oxide gas [¹⁰].

Despite advancements in implant technology aimed at improving bearing performance, costs remain prohibitively high for some patients, particularly in developing countries where affordability is a primary concern [¹¹]. Consequently, manufacturers avoid certain practices to reduce costs and provide more accessible products [¹², ¹³]. In this context, evaluating product quality involves using in vitro preclinical tests that simulate physiological loads and movements of the human hip joint [¹⁴]. The principal method for evaluating wear in hip tribological pairs is through hip joint simulators, yielding critical insights into expected implant behavior during clinical use [¹, ¹⁴]. These tests have been pivotal for developing superior implant technology, providing realistic scenarios comparable to in vivo THA use [¹, ¹⁵,¹⁶,¹⁷,¹⁸].

Recognizing the pivotal role of preclinical studies in assessing hip prostheses, this study aimed to conduct a comparative analysis of wear rates among hip prostheses from three distinct manufacturers. Additionally, the study investigated the influence of dimensional parameters of tribological pairs, as well as the physicochemical properties and packaging types of UHMWPE, on wear rates. Experiments were conducted under identical loading and displacement conditions using a unified simulator, ensuring simultaneous and comparable evaluations across all tested variables.

2. MATERIALS AND METHODS

2.1. Specimens

This preliminary investigation evaluated tribological pairs of hip prostheses from three different manufacturers designated as A, B and C. For all of the selected tribological pairs, the UHMWPE acetabular cups were manufactured in GUR 1020 resin according to ASTM F648-14 [¹⁹]. The acetabular cups of manufacturers B and C were sterilized with gamma radiation and manufacturer A used ethylene oxide. The femoral heads were manufactured from the same stainless steel, as recommended in ASTM F138-13 [²⁰]. The nominal diameter of the components was 28 mm.

2.2. Surface finish and dimensional analysis of the tribological pair

The roughness of the heads and acetabular cups were measured in accordance with ISO 4288:2008 [²¹] and ISO 7206-2:2017 [²²], using a profilometer (Taylor-Hobson Form Talysurf-120L) with cut-off values of 0.25 mm and 0.8 mm, respectively. The diameter of the head and acetabulum components were measured with a Mitutoyo coordinate measuring machine (model BATY IM 0283, with U= 0.005 mm), also recommended in the norm ISO 7206-2:2017 [²²]. These analyses were performed before the wear testing of each component of the tribological pairs. Based on the measured diameters, it was possible to obtain the gap (diametrical clearance) between the components of the tribological pair.

2.3. Physicochemical properties and packing of UHMWPE

The oxidation index (IOX) and trans-vinylene index (TVI) were determined by Fourier transform infrared (FTIR) spectroscopy on a spectrophotometer (PerkinElmer, Frontier) using the transmission mode. The TVI was determined to evaluate if the UHMWPE samples had been submitted to gamma radiation and, if so, to estimate the radiation dosage. The IOX was determined to assess how much the samples were oxidized. To determine the crosslinking density, the acetabular cups were subjected to the swelling test. The test consists of immersing a sample of the polymer in xylene for 24 hours in a way that causes an increase in mass and volume. The standard provides for the calculation of the swelling ratio using Equation 1. Applying the FTIR and differential exploration calorimetry (DSC; Perkin Elmer 6000) techniques, the packages were evaluated based on the melting points and comparison with specific spectra. The packaging materials were identified and their effectiveness as a gas (oxygen) barrier was evaluated.

(1) $$\left[\left(\frac{M_m-M_o}{M_o-(M_o-M_f)}\right)*k\right]+1$$

2.4. Wear test

The wear testing of the tribological pairs was carried out on a hip joint simulator (model AMTI ADL-H06-1), designed to replicate the physiological environment of the joint and its movements, following the recommendations of ISO 14242-1 [⁹]. The test, applying 5 million cycles, was performed on three tribological pairs from each of the three manufacturers (A, B, and C) and thus a total of 15 million cycles per manufacturer was applied. The components of the tribological pair, consisting of a metallic femoral head and a UHMWPE acetabular insert, both 28 mm in diameter, were assembled in the apparatus as depicted in Figure 1, and coupled inside a bag with lubricating fluid based on fetal bovine serum with a protein mass concentration of 30 g/L (± 2 g/L), which was replaced every 500 thousand test cycles. The test was carried out considering three degrees of freedom in movement: abduction-adduction, internal-external rotation and flexion-extension, with a machine operating frequency of 1 Hz and a double peak loading curve with intensity ranging from 300 to 3000 N. To assess the wear rate of the acetabular inserts, the gravimetric method described in ISO 14242-2 [²³] was used. The cleaning and weighing of the acetabular inserts were carried out after half a million cycles, one million cycles, and then at one million-cycle intervals until 5 million cycles, i.e., the end of the test (giving a total of six stops). The weighing was performed with a precision scale (Shimadzu, AUW 2200), with an accuracy of 0.000001 g. The cleaning and weighing procedure were repeated at 24-h intervals until the incremental change in acetabular insert mass was less than 10% of the previous (cumulative) mass change. In order to ensure no influence of the hip simulator on the wear rate, the tribological pairs were interchanged on the six stations of the machine, with each tribological pair being tested on one station for each 5 million cycle period.

Figure 1
Sectional representation of the tribological couple assembly in the simulator device.

3. RESULTS AND DISCUSSIONS

3.1. Surface finish and dimensional results

The diameter, roughness and diametrical clearance results of the three tribological pairs from each manufacturer are presented in Table 1, designated as n1, n2 and n3. The three acetabular cups from Manufacturer A had a diameter above the limit allowed by the standard (28.3 mm). The diametrical clearance for the pairs was calculated using the difference between the diameter of the acetabular cup and the diameter of the femoral head. The gaps for the tribological pairs are shown in Table 1. These values are within the 0.5 mm maximum clearance limit allowed by the standard. Only the second tribological pair from Manufacturer A had a diametrical clearance above the maximum allowable limit. The femoral heads from manufacturer B showed higher roughness results than other manufacturers, but still within the maximum limit of 0.05 allowed by ISO 7206-2:2017 [²²].

Table 1
Results for the initial diameter, roughness and radial diametrical clearance of the inserts.

MANUFACTURER	ACETABULAR CUP		FEMORAL HEAD		CLEARANCE (MM)
	DIAMETER (MM)	ROUGHNESS (CUT-OFF 0.8 MM)	DIAMETER (MM)	ROUGHNESS (CUT-OFF 0.25 MM)
A (n1)	28,401 ± 0.008	1.18 ± 0.03	27.975 ± 0.006	0.014 ± 0.01	0.380
A (n3)	28.478 ± 0.008	0.24 ± 0.02	27.976 ± 0.006	0.012 ± 0.01	0.502
A (n3)	28.371 ± 0.008	0.31 ± 0.02	27.981 ± 0.006	0.013 ± 0.01	0.390
B (n1)	28.169 ± 0.008	1.54 ± 0.03	27.899 ± 0.006	0.040 ± 0.01	0.270
B (n2)	28.212 ± 0.008	1.85 ± 0.04	27.934 ± 0.006	0.020 ± 0.01	0.278
B (n3)	28.200 ± 0.008	1.30 ± 0.02	27.987 ± 0.006	0.035 ± 0.01	0.213
C (n1)	28.026 ± 0.008	0.33 ± 0.01	27.931 ± 0.006	0.016 ± 0.01	0.095
C (n2)	28.056 ± 0.008	0.62 ± 0.01	27.938 ± 0.006	0.020 ± 0.01	0.118
C (n3)	28.130 ± 0.008	0.67 ± 0.02	27.941 ± 0.006	0.021 ± 0.01	0.189

3.2. Physicochemical properties and packing of UHMWPE

The results for the physicochemical properties of the acetabular cups before the start of the wear test are presented in Table 2. The IOX values for the UHMWPE of sample B were higher compared with samples A and C. Values up to a maximum of 0.240 are cited as acceptable in the literature for implanted prostheses within their period of validity [³], [¹¹] and [¹³]. Therefore, only sample B does not fit the expected IOX value for prostheses before implant, with an average of 0.329.

Table 2
Results for the initial physicochemical characterization of acetabular cups of UHMWPE.

MANUFACTURER	OXIDATION (IOX)	TRANS-VINYLENE (TVI)	SWELLING RATIO
A	0.090 ± 0.004	0,00	13
B	0.329 ± 0.027	0.018 ± 0.001	7
C	0.110 ± 0.010	0.016 ± 0.001	3

The TVI values observed for sample B (0.018) and sample C (0.016) are within the acceptable range reported in the literature (0.011 – 0.018) [¹⁴,¹⁵,¹⁶]. Sample A showed no detectable values for TVI, indicating that it had been exposed to ethylene oxide (ETO) sterilization and suggesting the absence of crosslinking in its structure.

The crosslinking density was determined based on the swelling ratio, which is shown in Table 2. The UHMWPE from sample A showed the highest value of the three specimens, suggesting a low degree of crosslinking, as expected based on the IOX and TVI results. The TVI index results indicated that samples B and C were sterilized by gamma radiation and that sample B received a greater amount of radiation than sample C. However, sample B showed a higher degree of swelling, suggesting a lower degree of crosslinking when compared to sample C.

The absence of proper sealing in the packing of sample B suggests that the acetabular cup was exposed to atmospheric air after gamma irradiation, which explains the elevated IOX values (Table 2). Higher oxygen permeability indicates that oxygen can diffuse into the material, thereby causing greater oxidation in the presence of free radicals [²⁴]. The packaging of sample C was made of aluminum foil, which works as an air barrier, explaining the elevated TVI (0.016) but low oxidation (0.110), which shown in Table 3.

Table 3
Summary of materials used for packing of UHMWPE components [8].

MANUFACTURER	PACKING OF UHMWPE COMPONENTS
A	Two packages of PE with paper bottom
B	Double blister of PET covered with paper sheet
C	Double blister of PAN-PMMA covered with aluminum sheet

3.3. Wear rate

The results for the gravimetric wear obtained in the hip joint simulator for the three tribological pairs from each of the three manufacturers are shown in Table 4. The average wear rate per million cycles was calculated through linear regression employing the least-squares method.

Table 4
Wear rate in mg/million cycles.

MANUFACTURER	SAMPLE 1	SAMPLE 2	SAMPLE 3	AVERAGE
A	70.54 ± 11.55	70.34 ± 5.18	61.34 ± 16.13	67.41 ± 6.91
B	70.67 ± 8.78	82.49 ± 9.27	61.98 ± 14.20	71.71 ± 10.61
C	46.82 ± 11.36	50.32 ± 12.24	42.63 ± 5.17	46.59 ± 5.60

• Standard error was calculated for each of the manufacturers tested in triplicate: A = 3.03; B = 6.36; C = 5.83.

All tribological pairs tested presented an r-squared value greater than 0.99, indicating that there was linear wear throughout the test, which can be attributed to the fact that the testing of the tribological pairs of the three manufacturers were performed simultaneously, with the rotation of the stations at scheduled stops, eliminating the test equipment variable.

3.4. Correlation of results

Some authors have studied the wear rate as a function of the clearance and reported that extremely low clearance can cause reduced film thickness of the lubricating fluid and increase the wear rate [²⁵, ²⁶]. However, these authors also found that a larger gap between tribological pairs leads to greater contact stress in a small area, which may increase the wear rate. The conclusion drawn from clinical studies carried out by two different research groups using finite elements was that the wear and tear resulting from hip movement is smaller for gaps between 0.10 mm and 0.15 mm, because this clearance promotes a film of thick fluid that is sufficient for there to be a pressure distribution over a larger contact area [²⁷, ²⁸]. Our results show that sample C presented a gap close to the above-mentioned values and had the lowest wear rate. Samples A and B had a diameter slightly above that specified by the standard, however, this diameter still provides a clearance within the suggested range (0.10 mm and 0.50 mm).

The roughness results for both components of the tribological pair were in accordance with the requirements established by ISO 7206-2:2017 [²²]. The maximum roughness values (Ra) recommended by ISO 7206-2: 2017 [²²] are 2.0 μm for the UHMWPE acetabular cup (cut-off 0.8 mm) and 0.05 μm for the femoral head (cut-off 0.25 mm) This standard suggests a nominal diameter of 27.8 to 28.0 mm for the femoral head and 28.1 to 28.3 mm for the acetabular dome. The value for the acetabular cup roughness of sample C was less than those for the other specimens. ELFICK et al. [²⁹] also observed higher wear rates for the UHMWPE acetabular cups that had greater initial roughness, mainly in the initial part of the test. According to authors who have studied the relationship between the roughness and wear rate in the laboratory (in vitro) and in clinical studies (in vivo), hip prostheses undergo a period of adaptation in the body. This could explain the fact that during the initial test period the volumetric wear rate was significantly higher than the average observed over the whole of the test period [³⁰, ³¹]. Higher roughness is usually associated with machining marks remaining from the manufacturing process, which are removed in the initial period of in vitro testing or in vivo clinical use.

There is a series of tests available to investigate the effects of sterilization and packaging on the properties of UHMWPE. These effects include changes in the morphological characteristics and in the physicochemical and mechanical properties as well as the generation of reactive chemical species, and these directly influence the wear resistance [¹⁷]. Sample A had the highest swelling index, indicating that the degree of crosslinking is low or zero, which corroborates with the low oxidation index obtained for this sample. According to BERTOLI [³²], the fact that sample A was packaged in an oxygen-containing environment is not cause for concern, since this sample was submitted to EtO sterilization, which does not generate free radicals that are associated with sample oxidation during shelf storage [¹⁷]. But on the other hand, ethylene oxide sterilization does not have the potential to improve mechanical properties, if used correctly, compared to the use of gamma radiation. On the other hand, the IOX and swelling ratio results indicate that samples B and C had been subjected to sterilization via gamma irradiation.

The highest wear rate observed in sample B may be related to the high IOX (0.329) of the material observed in the FTIR analysis. The exposure of UHMWPE to gamma radiation in a non-controlled environment can generate crosslinking as well as chain scission and the formation of new functional groups. Chain scission reduces the molecular weight of the polymer [³³, ³⁴, ³⁵]. UHMWPE has a high resistance to wear provided by its non-radicular long chains, which brings the structures closer to each other, enabling stronger secondary forces links. Once the chains are broken, the long extensions of secondary forces are also broken and the resistance to wear decreases [³, ³²]. Also, in the presence of oxygen during irradiation or the shelf-life, molecular scission predominates over crosslinking and therefore oxidation predominates [³⁶].

The oxidative degradation of UHMWPE leads to significant changes in its mechanical properties and, in particular, to embrittlement [³⁷]. Although the proximity between the chains provides greater secondary forces interactions between one chain and another, the low amount of free space hinders the movement of these chains in the crystallization process. With the breaking of the chain, the energy required for crystallization decreases, as shown by the increase in delta H observed in the DSC analysis, revealing a crystalline brittle structure [³⁸]. The embrittlement has also been observed in indentation tests conducted by other authors [³⁶, ³⁹].

Studies have demonstrated an increase in the elastic modulus and a decrease in elongation to break, final stress and toughness. These changes in the properties have been noted in two different scenarios. Oxidation results in a cascade scission of the chains, which will affect the mechanical properties [³⁶]. On another hand, highly irradiated structures result in a high number of free radicals, which will not link to form a network, producing smaller reactive chains [⁴⁰]. Moreover, a decrease in fatigue crack propagation resistance was also verified in oxidized samples resulting in a dramatic reduction in wear resistance [³⁸, ⁴¹]. Although sample C showed evidence of crosslinking (TVI = 0.016) and also presented a low swelling rate, the wear rate for this material was higher than that of the samples without crosslinking [⁴²]. However, it is known that in in vitro tests the UHMWPE wear rates are influenced by a number of factors, that is, not only the roughness and hardness of the metallic material but also the type of lubricant and the tribological position used in the test along with the sterilization technique and packing of the acetabular polyethylene cup. As previously suggested, the UHMWPE of sample C was submitted to sterilization via gamma radiation combined with barrier packaging, which resulted in a low oxidation index and a high degree of crosslinking based on the swelling test. When the radiation process occurs under an inert atmosphere, the predominant effect is the formation of crosslinks between the polymer chains. Since crosslinking induces carbon-carbon bonds between adjacent chains, reducing the chain motility and inhibiting this molecular orientation, it is effective in retarding the formation of surface fibrils and rendering the polyethylene more wear-resistant [⁴³]. Several studies published in the literature report improved in vitro wear performance for irradiated UHMWPE compared to conventional UHMWPE [⁴³, ⁴⁴]. The wear rates observed in the tribological pairs used in this study are consistent with the wear rates found in simulated wear studies of hip implants with metal-polymer components reported in the literature. Specifically, in the case of wear tests with the metal-UHMWPE tribological pair, several authors have also reported similar results. Furthermore, the results obtained in our tests align with the literature review of in vitro studies involving both conventional and crosslinked UHMWPE components in combination with metallic femoral heads of various compositions, including 28 mm diameters [⁴⁵,⁴⁶,⁴⁷,⁴⁸,⁴⁹].

An intermediate effect on the wear rate was found for sample A compared to samples B and C. This material did not show the presence of trans-vinyl chemical bonds in the FTIR test and its packaging did not provide a barrier to oxygen, so it can be assumed that that sterilization was carried out with an alternative process such as ETO. This method does not generate free radicals. However, crosslinking of the polyethylene does not occur and consequently this procedure does not promote better wear resistance. A similarity in the results for the wear rates of samples A and B can be noted, which was not expected since the UHMWPE of sample B received gamma radiation while sample A received only ETO treatment. Thus, these results could be associated with the sterilization method and the absence of an oxygen barrier in the packaging of sample B.

4. CONCLUSIONS

In conclusion, our study investigated the complex interplay of roughness, sterilization method, and material properties on the wear rates of UHMWPE used in hip prostheses. The findings underscore that optimal wear performance is closely linked to a balance in these factors. Specifically, maintaining a clearance between 0.10 mm and 0.15 mm promotes sufficient lubrication and pressure distribution, resulting in reduced wear. Additionally, lower roughness on both components of the tribological pair correlates with decreased wear rates, as observed in sample C.

Sterilization method also emerged as a critical determinant: gamma irradiation combined with effective barrier packaging (manufacturer C) demonstrated superior wear resistance compared to ETO sterilization without barrier packaging (manufacturer A). This is attributed to the protective effect of crosslinking induced by gamma irradiation, which enhances polymer chain stability and reduces susceptibility to oxidative degradation.

Furthermore, our results highlighted the detrimental effects of oxidation and chain scission, evidenced by higher wear rates in samples with higher oxidative indices (manufacturer B). These findings underscore the importance of carefully controlled sterilization processes and packaging strategies to optimize the long-term performance of UHMWPE implants.

In conclusion, while our study contributes valuable insights into the factors influencing wear rates in UHMWPE hip prostheses, further research is necessary to refine our understanding and potentially enhance the durability and reliability of these critical medical devices.

5. ACKNOWLEDGMENTS

Fundo Nacional de Saúde (FNS) and Financiadora de Estudos e Projetos (FINEP).

6. BIBLIOGRAPHY

• ^[1]
  TROMMER, R.M., MARU, M.M., “Importance of preclinical evaluation of wear in hip implant designs using simulator machines”, Revista Brasileira de Ortopedia, v. 52, n. 3, pp. 251–259, May. 2017. doi: http://doi.org/10.1016/j.rboe.2016.07.004. PubMed PMID: 28702381.
  » https://doi.org/10.1016/j.rboe.2016.07.004
• ^[2]
  COSTA, L., LUDA, M.P., TROSSARELLI, L., et al, “Oxidation in orthopaedic UHMWPE sterilized by gamma-radiation and ethylene oxide”, Biomaterials, v. 19, n. 7–9, pp. 659–668, Apr. 1998. doi: http://doi.org/10.1016/S0142-9612(97)00160-9. PubMed PMID: 9663738.
  » https://doi.org/10.1016/S0142-9612(97)00160-9
• ^[3]
  ZHANG, D., LIU, H., WANG, J., et al, “Wear mechanism of artificial joint failure using wear debris analysis”, Journal of Nanoscience and Nanotechnology, v. 18, n. 10, pp. 6805–6814, Jun. 2018. doi: http://doi.org/10.1166/jnn.2018.15513. PubMed PMID: 29954497.
  » https://doi.org/10.1166/jnn.2018.15513
• ^[4]
  ULRICH, S.D., SEYLER, T.M., BENNETT, D., et al, “Total hip arthroplasties: what are the reasons for revision?”, International Orthopaedics, v. 32, n. 5, pp. 597–604, Oct. 2008. doi: http://doi.org/10.1007/s00264-007-0364-3. PubMed PMID: 17443324.
  » https://doi.org/10.1007/s00264-007-0364-3
• ^[5]
  MAITZ, M.F., “Applications of synthetic polymers in clinical medicine”, Biosurface and Biotribology, v. 1, n. 3, pp. 161–176, Sep. 2015. doi: http://doi.org/10.1016/j.bsbt.2015.08.002.
  » https://doi.org/10.1016/j.bsbt.2015.08.002
• ^[6]
  SPIEGELBERG, S., KOZAK, A., BRAITHWAITE, G., “Characterization of Physical, Chemical, and Mechanical Properties of UHMWPE,” In: UHMWPE Biomaterials Handbook: Ultra High Molecular Weight Polyethylene in Total Joint Replacement and Medical Devices, 3rd ed., Amsterdam, Elsevier, 2016, pp. 531–552. doi: http://doi.org/10.1016/B978-0-323-35401-1.00029-6.
  » https://doi.org/10.1016/B978-0-323-35401-1.00029-6
• ^[7]
  O. R. Mahon and A. Dunne, “Disease-associated particulates and joint inflammation, mechanistic insights and potential therapeutic targets,” Frontiers in Immunology, vol. 9, 2018. doi: http://doi.org/10.3389/fimmu.2018.01145.
  » https://doi.org/10.3389/fimmu.2018.01145
• ^[8]
  COSTA, L., BRACCO, P., BRACH DEL PREVER, E.M., et al, “Oxidation and oxidation potential in contemporary packaging for polyethylene total joint replacement components”, Journal of Biomedical Materials Research. Part B, Applied Biomaterials, v. 78B, n. 1, pp. 20–26, Jul. 2006. doi: http://doi.org/10.1002/jbm.b.30454. PubMed PMID: 16470814.
  » https://doi.org/10.1002/jbm.b.30454
• ^[9]
  BRACCO, P., BRUNELLA, V., LUDA, M.P., et al, “Radiation-induced crosslinking of UHMWPE in the presence of co-agents: chemical and mechanical characterisation”, Polymer, v. 46, n. 24, pp. 10684–10657, 2005. doi: http://doi.org/10.1016/j.polymer.2005.08.095.
  » https://doi.org/10.1016/j.polymer.2005.08.095
• ^[10]
  AFFATATO, S., BERSAGLIA, G., EMILIANI, D., et al, “The performance of gamma- and EtO-sterilised UHMWPE acetabular cups tested under severe simulator conditions. Part 2: Wear particle characteristics with isolation protocols”, Biomaterials, v. 24, n. 22, pp. 4045–4055, 2003. doi: http://doi.org/10.1016/S0142-9612(03)00264-3. PMid:12834600.
  » https://doi.org/10.1016/S0142-9612(03)00264-3
• ^[11]
  TSIKANDYLAKIS, G., OVERGAARD, S., ZAGRA, L., et al, “Global diversity in bearings in primary THA”, EFORT Open Reviews, v. 5, n. 10, pp. 763–775, Jan. 2020. doi: http://doi.org/10.1302/2058-5241.5.200002. PubMed PMID: 33204520.
  » https://doi.org/10.1302/2058-5241.5.200002
• ^[12]
  CHEN, D.Q., PARVATANENI, H.K., MILEY, E.N., et al, “Lessons learned from the comprehensive care for joint replacement model at an academic tertiary center: the good, the bad, and the ugly”, The Journal of Arthroplasty, v. 38, n. 7, pp. S54–S62, Jul. 2023. doi: http://doi.org/10.1016/j.arth.2023.02.014. PubMed PMID: 36781061.
  » https://doi.org/10.1016/j.arth.2023.02.014
• ^[13]
  KINGORI, P., PEETERS GRIETENS, K., ABIMBOLA, S., and RAVINETTO, R., “Poor-quality medical products: Social and ethical issues in accessing ‘quality’ in global health,” BMJ Global Health, vol. 4, no. 6., 2019. doi: http://doi.org/10.1136/bmjgh-2019-002151.
  » https://doi.org/10.1136/bmjgh-2019-002151
• ^[14]
  SHEN, G., ZHANG, J.F., FANG, F.Z., “In vitro evaluation of artificial joints: a comprehensive review”, Adv Manuf, v. 7, n. 1, pp. 1–14, Mar. 2019. doi: http://doi.org/10.1007/s40436-018-00244-z.
  » https://doi.org/10.1007/s40436-018-00244-z
• ^[15]
  LESTARI, W.D., NUGROHO, A., ISMAIL, R., et al, “Study of wear performance of crosslinking UHMWPE acetabular liner for artificial hip joint made from CNC milling”, In: IOP Conf Ser Mater Sci Eng, v. 1078, n. 1, pp. 012009, Feb. 2021. doi: http://doi.org/10.1088/1757-899X/1078/1/012009.
  » https://doi.org/10.1088/1757-899X/1078/1/012009
• ^[16]
  HUA, Z., DOU, P., JIA, H., et al, “Wear test apparatus for friction and wear evaluation hip prostheses”, Frontiers of Mechanical Engineering, v. 5, pp. 12, Apr. 2019. doi: http://doi.org/10.3389/fmech.2019.00012.
  » https://doi.org/10.3389/fmech.2019.00012
• ^[17]
  LOVING, L.Q., LEE, R.K.F., HERRERA, L., et al, “Wear performance evaluation of a contemporary dual mobility hip bearing using multiple hip simulator testing conditions”, The Journal of Arthroplasty, v. 28, n. 6, pp. 1041–1046, Jun. 2013. doi: http://doi.org/10.1016/j.arth.2012.09.011. PubMed PMID: 23434106.
  » https://doi.org/10.1016/j.arth.2012.09.011
• ^[18]
  WANG, A., ESSNER, A., COOPER, J., “The clinical relevance of hip simulator testing of high performance implants”, Seminars in Arthroplasty, v. 17, n. 2, pp. 49–55, 2006. doi: http://doi.org/10.1053/j.sart.2006.06.005.
  » https://doi.org/10.1053/j.sart.2006.06.005
• ^[19]
  AMERICAN SOCIETY FOR TESTING AND MATERIALS, ASTM F648: Standard Specification for Ultra-High-Molecular-Weight Polyethylene Powder and Fabricated Form for Surgical Implants 1, West Conshohocken, ASTM, 202. doi: http://doi.org/10.1520/F0648-21
  » https://doi.org/10.1520/F0648-21
• ^[20]
  AMERICAN SOCIETY FOR TESTING AND MATERIALS, ASTM F138: Standard Specification for Wrought 18Chromium-14Nickel-2.5Molybdenum Stainless Steel Bar and Wire for Surgical Implants, West Conshohocken, ASTM, 2019. doi: 10.1520/F0138-19.2
  » https://doi.org/10.1520/F0138-19.2
• ^[21]
  ASSOCIAÇÃO BRASILEIRA DE NORMAS TÉCNICAS, ABNT NBR ISO 4288: Especificações geométricas do produto (GPS) — Rugosidade: Método do perfil — Regras e procedimentos para avaliação de rugosidade, Rio de Janeiro, ABNT, 2008.
• ^[22]
  ASSOCIAÇÃO BRASILEIRA DE NORMAS TÉCNICAS, ABNT 7206-2Implantes para cirurgia — Próteses parcial e total de articulação de quadril - Parte 2: Superfícies de articulação feitas de materiais metálico, cerâmico e plástico, Rio de Janeiro, ABNT, 2017.
• ^[23]
  ASSOCIAÇÃO BRASILEIRA DE NORMAS TÉCNICAS, ABNT 14242-2: Implantes para cirurgia - Desgaste de próteses totais de articulação do quadril Parte 2: Métodos de medição, Rio de Janeiro, ABNT, 2017.
• ^[24]
  BUCHANAN, F.J., SIM, B., DOWNES, S., “Influence of packaging conditions on the properties of gamma-irradiated UHMWPE following accelerated ageing and shelf ageing”, Biomaterials, v. 20, n. 9, pp. 823–837, 1999. doi: http://doi.org/10.1016/S0142-9612(98)00237-3. PubMed PMID: 10226709.
  » https://doi.org/10.1016/S0142-9612(98)00237-3
• ^[25]
  MATTEI, L., DI PUCCIO, F., PICCIGALLO, B., et al, “Lubrication and wear modelling of artificial hip joints: a review”, Tribology International, v. 44, n. 5, pp. 532–549, 2011. doi: http://doi.org/10.1016/j.triboint.2010.06.010.
  » https://doi.org/10.1016/j.triboint.2010.06.010
• ^[26]
  TUDOR, A., LAURIAN, T., POPESCU, V.M., “The effect of clearance and wear on the contact pressure of metal on polyethylene hip prostheses”, Tribology International, v. 63, pp. 158–168, 2013. doi: http://doi.org/10.1016/j.triboint.2012.11.002.
  » https://doi.org/10.1016/j.triboint.2012.11.002
• ^[27]
  SEMLITSCH, M., WILLERT, H.G., “Clinical wear behaviour of ultra-high molecular weight polyethylene cups paired with metal and ceramic ball heads in comparison to metal-on-metal pairings of hip joint replacements”, Proceedings of the Institution of Mechanical Engineers. Part H, Journal of Engineering in Medicine, v. 211, n. 1, pp. 73–88, 1997. doi: http://doi.org/10.1243/0954411971534700. PubMed PMID: 9141893.
  » https://doi.org/10.1243/0954411971534700
• ^[28]
  TEOH, S.H., CHAN, W.H., THAMPURAN, R., “An elasto-plastic finite element model for polyethylene wear in total hip arthroplasty”, Journal of Biomechanics, v. 35, n. 3, pp. 323–330, Mar. 2002. doi: http://doi.org/10.1016/S0021-9290(01)00215-9. PubMed PMID: 11858807.
  » https://doi.org/10.1016/S0021-9290(01)00215-9
• ^[29]
  ELFICK, A.P.D., SMITH, S.L., GREEN, S.M., et al, “The quantitative assessment of UHMWPE wear debris produced in hip simulator testing: the influence of head material and roughness, motion and loading”, Wear, v. 249, n. 5–6, pp. 517–527, 2001. doi: http://doi.org/10.1016/S0043-1648(01)00589-0.
  » https://doi.org/10.1016/S0043-1648(01)00589-0
• ^[30]
  SMITH, S.L., UNSWORTH, A., “A comparison between gravimetric and volumetric techniques of wear measurement of UHMWPE acetabular cups against zirconia and cobalt-chromium-molybdenum femoral heads in a hip simulator”, Proceedings of the Institution of Mechanical Engineers. Part H, Journal of Engineering in Medicine, v. 213, n. 6, pp. 475–483, 1999. doi: http://doi.org/10.1243/0954411991535086. PubMed PMID: 10635696.
  » https://doi.org/10.1243/0954411991535086
• ^[31]
  SMITH, S.L., ELFICK, A.P.D., UNSWORTH, A., “Evaluation of the tribological performance of zirconia and CoCrMo femoral heads”, Journal of Materials Science, v. 34, n. 21, pp. 5159–5162, 1999. doi: http://doi.org/10.1023/A:1004737526529.
  » https://doi.org/10.1023/A:1004737526529
• ^[32]
  BERTOLI, G., “Estudo da estrutura e morfologia de acetábulos de UHMWPE fabricados por meio de usinagem de barras moldadas,” Tese de M.Sc., Florianópolis, UFSC, 2017.
• ^[33]
  COSTA, L., JACOBSON, K., BRACCO, P., et al, “Oxidation of orthopaedic UHMWPE”, Biomaterials, v. 23, n. 7, pp. 1613–1624, 2002. doi: http://doi.org/10.1016/S0142-9612(01)00288-5. PubMed PMID: 11924586.
  » https://doi.org/10.1016/S0142-9612(01)00288-5
• ^[34]
  ZHANG, H., ZHAO, S., XIN, Z., et al, “Wear resistance mechanism of ultrahigh-molecular-weight polyethylene determined from its structure-property relationships”, Industrial & Engineering Chemistry Research, v. 58, n. 42, pp. 19519–19530, 2019. doi: http://doi.org/10.1021/acs.iecr.9b04721.
  » https://doi.org/10.1021/acs.iecr.9b04721
• ^[35]
  KELLY, J.M., “Ultra-high molecular weight polyethylene”, Journal of Macromolecular Science, Part C: Polymer Reviews, v. 42, n. 3, pp. 355–371, 2002. doi: http://doi.org/10.1081/MC-120006452.
  » https://doi.org/10.1081/MC-120006452
• ^[36]
  BRACCO, P., BELLARE, A., BISTOLFI, A., et al, “Ultra-high molecular weight polyethylene: influence of the chemical, physical and mechanical properties on the wear behavior”, Materials (Basel), v. 10, n. 7, pp. 791, 2017. doi: http://doi.org/10.3390/ma10070791. PubMed PMID: 28773153.
  » https://doi.org/10.3390/ma10070791
• ^[37]
  MARKUT-KOHL, R., ARCHODOULAKI, V.M., SEIDLER, S., et al, “PE-UHMW in hip implants: properties of conventional and crosslinked prosthetic components”, Advanced Engineering Materials, v. 11, n. 10, pp. 148–154, 2009. doi: http://doi.org/10.1002/adem.200900050.
  » https://doi.org/10.1002/adem.200900050
• ^[38]
  LASKA, A., ARCHODOULAKI, V.-M., DUSCHER, B., “Failure analysis of retrieved PE-UHMW acetabular liners”, Journal of the Mechanical Behavior of Biomedical Materials, v. 61, pp. 70–78, Aug. 2016. doi: http://doi.org/10.1016/j.jmbbm.2016.01.007. PubMed PMID: 26849029.
  » https://doi.org/10.1016/j.jmbbm.2016.01.007
• ^[39]
  ZHANG, L., SAWAE, Y., YAMAGUCHI, T., et al, “Investigation on oxidation of shelf-aged crosslinked Ultra-High Molecular Weight Polyethylene (UHMWPE) and its effects on wear characteristics”, Tribology Online, v. 10, n. 1, pp. 1–10, 2015. doi: http://doi.org/10.2474/trol.10.1.
  » https://doi.org/10.2474/trol.10.1
• ^[40]
  HUOT, J.C., VAN CITTERS, D.W., CURRIER, J.H., et al, “The effect of radiation dose on the tensile and impact toughness of highly cross‐linked and remelted ultrahigh‐molecular weight polyethylenes”, Journal of Biomedical Materials Research. Part B, Applied Biomaterials, v. 97, n. 2, pp. 327–333, 2011. doi: http://doi.org/10.1002/jbm.b.31818. PubMed PMID: 21394903.
  » https://doi.org/10.1002/jbm.b.31818
• ^[41]
  PREMNATH, V., HARRIS, W.H., JASTY, M., et al, “Gamma sterilization of UHMWPE articular implants: an analysis of the oxidation problem”, Biomaterials, v. 17, n. 18, pp. 1741–1753, Sep. 1996. doi: http://doi.org/10.1016/0142-9612(95)00349-5. PubMed PMID: 8879511.
  » https://doi.org/10.1016/0142-9612(95)00349-5
• ^[42]
  TROMMER, R.M., MARU, M.M., OLIVEIRA FILHO, W.L., et al, “multi-scale evaluation of wear in UHMWPE-metal hip implants tested in a hip joint simulator”, Biotribology (Oxford), v. 4, pp. 1–11, 2015. doi: http://doi.org/10.1016/j.biotri.2015.08.001.
  » https://doi.org/10.1016/j.biotri.2015.08.001
• ^[43]
  STOJILOVIC, N., DORDEVIC, S.V., STOJADINOVIC, S., “Effects of clinical X-ray irradiation on UHMWPE films”, Nuclear Instruments & Methods in Physics Research. Section B, Beam Interactions with Materials and Atoms, v. 410, pp. 139–143, Nov. 2017. doi: http://doi.org/10.1016/j.nimb.2017.08.023.
  » https://doi.org/10.1016/j.nimb.2017.08.023
• ^[44]
  OONISHI, H., TAKAYAMA, Y., TSUJI, E., “Improvement of polyethylene by irradiation in artificial joints”, International Journal of Radiation Applications and Instrumentation Part C Radiation Physics and Chemistry, v. 39, n. 6, pp. 495–504, Jun. 1992. doi: http://doi.org/10.1016/1359-0197(92)90102-L.
  » https://doi.org/10.1016/1359-0197(92)90102-L
• ^[45]
  AFFATATO, S., DE MATTIA, J.S., BRACCO, P., et al, “Wear performance of neat and vitamin E blended highly cross-linked PE under severe conditions_ The combined effect of accelerated ageing and third body particles during wear test”, Journal of the Mechanical Behavior of Biomedical Materials, v. 64, pp. 240–252, 2016. doi: http://doi.org/10.1016/j.jmbbm.2016.08.003. PubMed PMID: 27522313.
  » https://doi.org/10.1016/j.jmbbm.2016.08.003
• ^[46]
  TROMMER, R.M., MARU, M.M., OLIVEIRA FILHO, W.L., et al, “Multi-scale evaluation of wear in UHMWPE-metal hip implants tested in a hip joint simulator”, Biotribology (Oxford), v. 4, pp. 1–11, 2015. doi: http://doi.org/10.1016/j.biotri.2015.08.001.
  » https://doi.org/10.1016/j.biotri.2015.08.001
• ^[47]
  ZIETZ, C., FABRY, C., MIDDELBORG, L., et al, “Wear testing and particle characterisation of sequentially crosslinked polyethylene acetabular liners using different femoral head sizes”, Journal of Materials Science. Materials in Medicine, v. 24, n. 8, pp. 2057–2065, Aug. 2013. doi: http://doi.org/10.1007/s10856-013-4936-z. PubMed PMID: 23615788.
  » https://doi.org/10.1007/s10856-013-4936-z
• ^[48]
  SCOTT, M., WIDDING, K., JANI, S., “Do current wear particle isolation procedures underestimate the number of particles generated by prosthetic bearing components?”, Wear, v. 251, n. 1–12, pp. 1213–1217, 2001. doi: http://doi.org/10.1016/S0043-1648(01)00762-1.
  » https://doi.org/10.1016/S0043-1648(01)00762-1
• ^[49]
  TIPPER, J.L., GALVIN, A.L., WILLIAMS, S., et al, “Isolation and characterization of UHMWPE wear particles down to ten nanometers in size from in vitro hip and knee joint simulators”, Journal of Biomedical Materials Research. Part A, v. 78, n. 3, pp. 473–480, Sep. 2006. doi: http://doi.org/10.1002/jbm.a.30824. PubMed PMID: 16721797.
  » https://doi.org/10.1002/jbm.a.30824

Publication Dates

• Publication in this collection
  11 Oct 2024
• Date of issue
  2024

History

• Received
  24 Apr 2024
• Accepted
  05 July 2024