CC BY-NC-ND 4.0 · Rev Bras Ortop (Sao Paulo) 2021; 56(01): 042-046
DOI: 10.1055/s-0040-1712491
Artigo Original
Joelho

Evaluation of Polyethylene Wear in a Brazilian Ultracongruent Knee Prosthesis with a Rotating Platform[*]

Article in several languages: português | English
1   Grupo do Joelho, Departamento de Ortopedia e Traumatologia, Instituto de Ortopedia e Traumatologia, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (HCFMUSP), São Paulo, SP, Brasil
,
2   Faculdade de Medicina, Universidade de Campinas, Campinas, SP, Brasil
› Author Affiliations
 

Abstract

Objective To evaluate the wear of polyethylene in a Brazilian ultracongruent knee prosthesis with a rotating platform (Rotaflex, Víncula, Rio Claro, SP, Brasil).

Methods We used the test method with the loading and preparation parameters mentioned in the standards regulation ISO 14243-1:2009, and the measurement methods mentioned in the standards regulation ISO 14243-2:2009, for the evaluation of the wear behavior of a Brazilian prosthesis with a rotating platform. The equipment used for the wear test was the ISO 14243–1 gait simulator (EndoLab, Riedering, Germany).

Results After 10 million cycles, the evaluation of the polyethylene wear showed a regular appearance of surface wear at a mean rate of 2.56 mg per million cycles.

Conclusion The wear of the polyethylene of the evaluated prosthesis was minimal after the tests performed and with safety limits higher than those recommended by biomechanical engineering.


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Introduction

The aging of the population and the higher prevalence of patients with osteoarthritis has increased the frequency of indications for total knee arthroplasty (TKA).[1] [2] Total knee arthroplasty can be defined as a highly-complex surgical procedure for the treatment of arthrosis that is capable of demonstrating satisfactory and long-lasting data on the improvement in pain, quality of life and patient functional outcomes, as well as in the correction of deformities and instabilities with origins related to degenerative processes that compromise the knee joint.[3] This procedure has excellent postoperative results in relation to implant survival, with rates higher than 95% in at least 10 years of follow-up.[4]

Polyethylene wear can produce debris that influences the release of prosthetic components. Total knee arthroplasty with a rotating platform has theoretical biomechanical advantages over a fixed-platform design.[5] These advantages include an improvement in kinematics by increasing the range of motion, facilitating axial rotation, better distribution of stress between the femoral and tibial components, and reduction in release forces at the implant interface with the bone.[6] [7] [8] Many variables can influence the frictional wear behavior of polyethylene, like the design of the prosthesis, the raw material used, and the surgical technique applied and the patient's morbidities, such as the activity level and body mass. The objective of the present study was to evaluate the wear of polyethylene of a Brazilian ultracongruent knee prosthesis with a rotating platform (Rotaflex, Víncula, São Paulo, SP, Brasil).


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Materials and Methods

We used the test method with the standard parameters for loading and preparation listed in the norm ISO 14243-1:2009–Implants for Surgery – Wear of Total Knee Joint Prostheses – Part 1: Loading and Displacement Parameters for Wear Testing Machines with Load Control and Corresponding Environmental Conditions for Tests (Accredited), and the measurement methods mentioned in the norm ISO 14243–2:2009 Implants for Surgery – Wear of Total Knee Joint Prostheses – Part 2: Methods of Measurement (Accredited). For the evaluation of the wear behavior, the Rotaflex prosthesis was used.[9] [10]

In total, 3 simultaneous tests were performed in the ISO 14243–1 knee joint gait simulator (EndoLab, Riedering, Germany) in 5 systems, totaling 15 components ([Figures 1] and [2]).

Zoom Image
Fig. 1 Representation of the individual test chamber.
Zoom Image
Fig. 2 Qualitative virtual analysis of the wear.

In the simulations, the implant was attached to the extension device. A cyclical flexion-extension variation from 0° to 58° was applied ([Table 1]). An axial force ranging from 168 N to 2,600 N was also applied, depending on the degree of flexion, simulating a normal human walk ([Table 1]). The tibial base was free to accommodate to the femoral component under the influence of applied contact forces, with this movement having all degrees of freedom, except the flexion-extension angle, which followed the specified cyclic variation. With this simulation, the applied contact force actions were: axial force, anteroposterior (AP) force, and tibial rotation torque. The femoral and tibial metal components, as well as the polyethylene, were immersed in a fluid medium simulating human synovial fluid throughout the test, which was carried out in a controlled environment, simulating the physiological conditions.

Table 1

Parameter

Values according to ISO 14243–1

Flexion/Extension

0° to 58°

Axial force

168 N to 2,600 N

Anteroposterior force

-265 N to 110 N

Torque

−1 Nm to 6 Nm

Frequency

1 Hz

Test fluid

Calf serum

Movement restriction - anteroposterior* (contrary to the positive anteroposterior movement)

9.3 N/mm

Movement restriction - anteroposterior* (contrary to the negative anteroposterior movement)

44 N/mm

Restriction of tibial rotation**

0.36 Nm/°

The wear assessment followed the ISO 14243–2:2009 norms, with 10 million cycles and measurements taken at every millionth cycle. In accordance with the aforementioned norms, the wear was assessed by analyzing the loss of mass.


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Results

After 10 million cycles, the qualitative analysis of the polyethylene surface showed an appearance of regular wear, with polished and matte areas ([Figure 2]). This regular wear pattern indicates an intrinsic stability of the prosthetic components ([Figure 3]).

Zoom Image
Fig. 3 X-UHMWPE insert wear versus number of cycles.

The quantitative result of mass wear for every millionth cycle is found in [Table 1]. [Figure 3] expresses the results mentioned in [Table 2].

Table 2

Coupling

1.1

1.2

1.3

Mass

Mass

Mass

Cycles (million)

X-UHMWPE 1.1 insert (g)

X-UHMWPE 1.1 insert (mg)

X-UHMWPE 1.2 insert (g)

X-UHMWPE 1.2 insert (mg)

X-UHMWPE 1.3 insert (g)

X-UHMWPE 1.3 insert (mg)

0.0

44.71242

0.00

44.48231

0.00

44.66329

0.00

0.5

44.70981

3.91

44.48121

2.41

44.65973

4.86

1.0

44.71073

4.24

44.48138

3.48

44.66000

5.84

2.0

44.71047

6.47

44.48102

5.81

44.65979

8.01

3.0

44.71210

6.71

44.48202

6.69

44.66085

8.83

4.0

44.71149

9.18

44.47986

10.70

44.65949

12.06

5.0

44.71378

9.30

44.48183

11.14

44.66343

10.52

6.0

44.71097

14.74

44.47747

18.13

44.65948

17.09

7.0

44.71004

15.47

44.47531

20.08

44.65842

17.95

7.5

44.71357

17.77

44.47810

23.13

44.66167

20.54

8.0

44.70607

22.38

44.47417

24.17

44.65625

23.06

9.0

44.70556

24.50

44.47504

24.90

44.65551

25.40

10.0

44.70660

25.23

44.47497

26.75

44.65645

26.24

The mean wear rate was 2.56 mg per millionth cycle, which was determined after 10 million cycles ([Figure 1]).


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Discussion

Total knee arthroplasty aims to promote pain relief and improve function in a lasting way. However, surgery can fail for a number of reasons, such as loosening of the components, infection, instability, and persistent pain, for example.[11] In order to reduce the wear of the polyethylene and consequently the production of debris, a tibial component with a rotating platform was created, in which the polyethylene can move rotationally over the tibial component, hypothetically reducing its friction and wear.[6] [7] [12]

In a study,[11] the authors state that prostheses with ultracongruent rotational support have the advantage of standardizing the contact pressures between components, thus reducing the formation of polyethylene particles and, consequently, osteolysis, in addition to the better adaptation of the extensor mechanism to possible imperfections in the rotational positioning of the tibial component.[11] An in-vivo video-fluoroscopic study, followed by three-dimensional reconstruction of the images obtained, comparing prostheses with fixed and mobile bases, with the same origin and design, showed that the femorotibial contact surface is twice as large in prostheses with rotational support when compared to those with fixed support.[13] In this study, the authors noted that the good results were similar in both models, but, both objectively and subjectively, the mobile platform was judged to be the closest to the normal knee.[13]

The high durability of prostheses with a rotating polyethylene component is well elucidated in the literature, and the prostheses can last for more than 20 years in 97.7% of cases.[14]

Schmidt et al[15] studied the wear rate of polyethylene in different models of prostheses already commercialized and established in the market, and they found values of volumetric wear that ranged from 1.9 mg/mc to 14.6 mg/mc. In the present study, the result obtained of 2.67 mg/mc of volumetric wear after 10 million test cycles, compared to the values found by Schmidt et al,[15] demonstrated that the Rotaflex system approaches the lowest rate found (1.9 mg/mc). In addition, the 2.67 mg/mc of wear of the polyethylene component measured in this Brazilian prosthesis obtained a wear resistance performance 5.47 times higher than the maximum published values.


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Conclusion

The wear of the polyethylene of the evaluated prosthesis was minimal after the tests performed with safety limits higher than those recommended by biomechanical engineering.


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Conflito de Interesses

Os autores declaram não haver conflito de interesses.

* Work developed at the Knee Group, Department of Orthopedics and Traumatology, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (HCFMUSP), São Paulo, SP, Brazil, and at Faculdade de Medicina, Universidade de Campinas, Campinas, SP, Brazil.


  • Referências

  • 1 Jämsen E, Jäntti P, Puolakka T, Eskelinen A. Primary knee replacement for primary osteoarthritis in the aged: gender differences in epidemiology and preoperative clinical state. Aging Clin Exp Res 2012; 24 (06) 691-698
  • 2 Hernandez AJ, Camanho GL, Pécora JR. Artrodese do joelho: gênese e soluções. São Paulo: Atheneu; 2010
  • 3 Ferreira MC, Oliveira JCP, Zidan FF, Franciozi CEDS, Luzo MVM, Abdalla RJ. Total knee and hip arthroplasty: the reality of assistance in Brazilian public health care. Rev Bras Ortop 2018; 53 (04) 432-440
  • 4 McLaughlin JR, Lee KR. Hybrid total knee arthroplasty: 10- to 16-year follow-up. Orthopedics 2014; 37 (11) e975-e977
  • 5 Tirico LEP, Pasqualin T, Pécora JO, Gobbi RG, Pécora JR, Demange MK. Estudo da estabilidade dos componentes na artroplastia total do joelho sem cimento. Acta Ortop Bras 2012; 20 (04) 230-234
  • 6 Kim YH, Park JW, Kim JS, Kulkarni SS, Kim YH. Long-term clinical outcomes and survivorship of press-fit condylar sigma fixed-bearing and mobile-bearing total knee prostheses in the same patients. J Bone Joint Surg Am 2014; 96 (19) e168
  • 7 Fransen BL, van Duijvenbode DC, Hoozemans MJM, Burger BJ. No differences between fixed- and mobile-bearing total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc 2017; 25 (06) 1757-1777
  • 8 Cobra H, Palma IM. Polietileno tibial móvel na artroplastia total do joelho. Rev Bras Ortop 2009; 44 (06) 475-478
  • 9 ISO 14243–1:2009 Implants for surgery - Wear of total knee-joint prostheses–Part 1: Loading and displacement parameters for wear-testing machines with load control and corresponding environmental conditions for test. Disponível em: https://www.iso.org/standard/44262.html
  • 10 ISO 14243–2:2009 Implants for surgery–Wear of total knee-joint prostheses–Part 2: Methods of measurement. Disponível em: https://www.iso.org/standard/44263.html
  • 11 Guglielmetti LG, Couto RC, Camargo OP. et al. Artroplastia total do joelho com o apoio tibial móvel. Avaliação dos resultados a médio prazo. Acta Ortop Bras 2010; 18 (06) 310-314
  • 12 Jorgensen NB, McAuliffe M, Orschulok T, Lorimer MF, de Steiger R. Major Aseptic Revision Following Total Knee Replacement: A Study of 478,081 Total Knee Replacements from the Australian Orthopaedic Association National Joint Replacement Registry. J Bone Joint Surg Am 2019; 101 (04) 302-310
  • 13 Ranawat CS, Flynn Jr WF, Saddler S, Hansraj KK, Maynard MJ. Long-term results of the total condylar knee arthroplasty. A 15-year survivorship study. Clin Orthop Relat Res 1993; (286) 94-102
  • 14 McEwen HM, McNulty DE, Auger DD. et al. Wear analysis of mobile bearing knee. In: Hamelynck KJ, Stiehl JB. editors. LCS mobile bearing knee arthroplasty: a 25 years worldwide review. Heidelberg, Germany: Springer Verlag; 2002: 67-73
  • 15 Scmidt R, Jinnah R, Green J, Moseley J, Brownhill J. In vitro assessment of a cruciate retaining and cruciate sacrificing medially pivoting knee replacement. In: Annual Meeting of the Orthopaedic Research Society 2011, Long Beach, CA, 2011. (Poster n° 1150. ORS 2011)

Endereço para correspondência

Valéria Romero, PhD
Faculdade de Medicina, Universidade de Campinas
Rua Sérgio Buarque de Holanda, Cidade Universitária, Campinas, SP, 13083859
Brasil   

Publication History

Received: 04 February 2020

Accepted: 02 March 2020

Article published online:
10 June 2020

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  • Referências

  • 1 Jämsen E, Jäntti P, Puolakka T, Eskelinen A. Primary knee replacement for primary osteoarthritis in the aged: gender differences in epidemiology and preoperative clinical state. Aging Clin Exp Res 2012; 24 (06) 691-698
  • 2 Hernandez AJ, Camanho GL, Pécora JR. Artrodese do joelho: gênese e soluções. São Paulo: Atheneu; 2010
  • 3 Ferreira MC, Oliveira JCP, Zidan FF, Franciozi CEDS, Luzo MVM, Abdalla RJ. Total knee and hip arthroplasty: the reality of assistance in Brazilian public health care. Rev Bras Ortop 2018; 53 (04) 432-440
  • 4 McLaughlin JR, Lee KR. Hybrid total knee arthroplasty: 10- to 16-year follow-up. Orthopedics 2014; 37 (11) e975-e977
  • 5 Tirico LEP, Pasqualin T, Pécora JO, Gobbi RG, Pécora JR, Demange MK. Estudo da estabilidade dos componentes na artroplastia total do joelho sem cimento. Acta Ortop Bras 2012; 20 (04) 230-234
  • 6 Kim YH, Park JW, Kim JS, Kulkarni SS, Kim YH. Long-term clinical outcomes and survivorship of press-fit condylar sigma fixed-bearing and mobile-bearing total knee prostheses in the same patients. J Bone Joint Surg Am 2014; 96 (19) e168
  • 7 Fransen BL, van Duijvenbode DC, Hoozemans MJM, Burger BJ. No differences between fixed- and mobile-bearing total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc 2017; 25 (06) 1757-1777
  • 8 Cobra H, Palma IM. Polietileno tibial móvel na artroplastia total do joelho. Rev Bras Ortop 2009; 44 (06) 475-478
  • 9 ISO 14243–1:2009 Implants for surgery - Wear of total knee-joint prostheses–Part 1: Loading and displacement parameters for wear-testing machines with load control and corresponding environmental conditions for test. Disponível em: https://www.iso.org/standard/44262.html
  • 10 ISO 14243–2:2009 Implants for surgery–Wear of total knee-joint prostheses–Part 2: Methods of measurement. Disponível em: https://www.iso.org/standard/44263.html
  • 11 Guglielmetti LG, Couto RC, Camargo OP. et al. Artroplastia total do joelho com o apoio tibial móvel. Avaliação dos resultados a médio prazo. Acta Ortop Bras 2010; 18 (06) 310-314
  • 12 Jorgensen NB, McAuliffe M, Orschulok T, Lorimer MF, de Steiger R. Major Aseptic Revision Following Total Knee Replacement: A Study of 478,081 Total Knee Replacements from the Australian Orthopaedic Association National Joint Replacement Registry. J Bone Joint Surg Am 2019; 101 (04) 302-310
  • 13 Ranawat CS, Flynn Jr WF, Saddler S, Hansraj KK, Maynard MJ. Long-term results of the total condylar knee arthroplasty. A 15-year survivorship study. Clin Orthop Relat Res 1993; (286) 94-102
  • 14 McEwen HM, McNulty DE, Auger DD. et al. Wear analysis of mobile bearing knee. In: Hamelynck KJ, Stiehl JB. editors. LCS mobile bearing knee arthroplasty: a 25 years worldwide review. Heidelberg, Germany: Springer Verlag; 2002: 67-73
  • 15 Scmidt R, Jinnah R, Green J, Moseley J, Brownhill J. In vitro assessment of a cruciate retaining and cruciate sacrificing medially pivoting knee replacement. In: Annual Meeting of the Orthopaedic Research Society 2011, Long Beach, CA, 2011. (Poster n° 1150. ORS 2011)

Zoom Image
Fig. 1 Representação da câmara de teste individual.
Zoom Image
Fig. 2 Análise virtual qualitativa do desgaste.
Zoom Image
Fig. 1 Representation of the individual test chamber.
Zoom Image
Fig. 2 Qualitative virtual analysis of the wear.
Zoom Image
Fig. 3 Desgaste do inserto X-UHMWPE versus número de ciclos.
Zoom Image
Fig. 3 X-UHMWPE insert wear versus number of cycles.