PIONEERING
As early as the 1970s, Robert Mathys, Sr. pursued the pioneering idea of developing isoelastic monoblock implants¹. This idea in combination with the equatorial pressfit described by Prof. Erwin Morscher^2,3 and the tribological option of a vitamin E-enriched, highly cross-linked polyethylene (VEPE)⁴ resulted in the unique RM Pressfit vitamys cup.

PROVEN
The basic philosophy based on Wolff’s law^1,5, which has proven its worth over many years, convinces with excellent clinical outcomes^{6 – 10} and outstanding international registry data^11–15.

ISOELASTIC
The elasticity of the RM Pressfit vitamys cup matches that of the surrounding bone¹⁶, thus having a positive impact on the stress shielding behaviour^17,25,26.

BONE PRESERVING
The interaction of low-wear isoelastic vitamys polyethylene (VEPE)⁴ with maximum wall thickness^17-19 and titanium particle coating reduces the risk of osteolysis^{4, 7, 20–23} and preserves the surrounding bone^{10, 24–27} in the long term.

EFFICIENT
Mathys-typical straightforward instruments support an efficient workflow. The monobloc design of the RM Pressfit vitamys cup moreover allows minimisation of implant warehousing space despite a comprehensive size range.

1. Mathys R. History – How the success story of the RM Classic cup started. In: Horne G (Editor). The RM Cup – Long-term experience with an elastic Monobloc acetabular implant. Einhorn-Presse Verlag. ISBN ISBN 978-3-88756-507-7. 2008;23-30.
2. Morscher E, Masar Z. Development and first experience with an uncemented press-fit cup. Clin Orthop Relat Res. 1988(232):96-103.
3. Morscher E W, Dick W. Cementless fixation of «isoelastic» hip endoprostheses manufactured from plastic materials. Clin Orthop Relat Res. 1983(176):77-87.
4. Beck M, Delfosse D, Lerf R, Becker R, French G, Hollmann L, Knahr K, Naeder H, Meijer E, Rehbein P, Baines J, Steenmeijer V, de Gast A. Oxidation Prevention with Vitamin E in a HXLPE Isoelastic Monoblock Pressfit Cup: Preliminary Results. In: Knahr K (Editor). Total Hip Arthroplasty. Springer Berlin Heidelberg. ISBN 978-3-642-27360-5. 2012;21-31.
5. Wolff J (Editor). Das Gesetz der Transformation der Knochen. ISBN ISBN 978-3-86805-648-8. 1892.
6. Erivan R, Eymond G, Villatte G, Mulliez A, Myriam G, Descamps S, Boiscgard S. RM Pressfit® cup: good preliminary results at 5 to 8 years follow-up for 189 patients. Hip Int. 2016.
7. Mahmood F F, Beck M, de Gast A, Rehbein P, French G J, Becker R, Dominkus M, Helmy N, Hollmann L, Baines J. Survivorship and Patient-Reported Outcomes of an Uncemented Vitamin E-Infused Monoblock Acetabular Cup: A Multicenter Prospective Cohort Study. J Arthroplasty. 2020.
8. Snijders T E, Halma J J, Massier J R A, van Gaalen S M, de Gast A. The Survivorship of the Uncemented Iso-Elastic Monoblock Acetabular Component at a Mean of 6-Year Follow-up. HSS Journal®. 2019.
9. Minten M J, Heesterbeek P J, Spruit M. No effect of additional screw fixation of a cementless, all-polyethylene press-fit socket on migration, wear, and clinical outcome. Acta Orthop. 2016:1-5.
10. Ihle M, Mai S, Pfluger D, Siebert W. The results of the titanium-coated RM acetabular component at 20 years: a long-term follow-up of an uncemented primary total hip replacement. J Bone Joint Surg Br. 2008;90(10):1284-90.
11. SIRIS. Swiss National Joint Registry – Annual Report 2021
12. NZJR. New Zealand Joint Registry – Annual Report. 2021
13. LROI. Dutch Arthroplasty Register – Annual Report. 2021
14. EPRD. Endoprothesenregister Deutschland – Jahresbericht. 2021
15. AOANJRR. Australian Orthopaedic Association National Joint Replacement Registry – Annual Report. 2021
16. Gasser B. Biomechanical principles and studies. In: Horne G (Editor). The RM Cup – Long-term experience with an elastic Monobloc acetabular implant. Einhorn-Presse Verlag. ISBN ISBN 978-3-88756-507-7. 2008;16-22.
17. Horne G, Devane P A, Dalton D J. Does pelvic osteolysis occur with a nonmodular uncemented acetabular component? J Arthroplasty. 2006;21(2):185-90.
18. Oonishi H, Iwaki H, Kin N, Kushitani S, Murata N, Wakitani S, Imoto K. The effects of polyethylene cup thickness on wear of total hip prostheses. J Mater Sci Mater Med. 1998;9(8):475-8.
19. Young A M, Sychterz C J, Hopper R H, Jr., Engh C A. Effect of acetabular modularity on polyethylene wear and osteolysis in total hip arthroplasty. J Bone Joint Surg Am. 2002;84-a(1):58-63.
20. Wyatt M, Weidner J, Pfluger D, Beck M. The RM Pressfit vitamys: 5-year Swiss experience of the first 100 cups. Hip Int. 2017;27(4):368-72.
21. Rochcongar G, Buia G, Bourroux E, Dunet J, Chapus V, Hulet C. Creep and Wear in Vitamin E-Infused Highly Cross-Linked Polyethylene Cups for Total Hip Arthroplasty: A Prospective Randomized Controlled Trial. J Bone Joint Surg Am. 2018;100(2):107-14.
22. Scemama C, Anract P, Dumaine V, Babinet A, Courpied J P, Hamadouche M. Does vitamin E-blended polyethylene reduce wear in primary total hip arthroplasty: a blinded randomised clinical trial. Int Orthop. 2016.
23. Rochcongar G, Remazeilles M, Bourroux E, Dunet J, Chapus V, Feron M, Praz C, Buia G, Hulet C. Reduced wear in vitamin E-infused highly cross-linked polyethylene cups: 5-year results of a randomized controlled trial. Acta Orthop. 2020:1-5.
24. Manley M T, Ong K L, Kurtz S M. The potential for bone loss in acetabular structures following THA. Clin Orthop Relat Res. 2006; 453:246-53.
25. Brodt S, Jacob B, Nowack D, Zippelius T, Strube P, Matziolis G. An Isoelastic Monoblock Cup Retains More Acetabular and Femoral Bone Than a Modular Press-Fit Cup: A Prospective Randomized Controlled Trial. J Bone Joint Surg Am. 2021.
26. Young P S, Macarico D T, Silverwood R K, Farhan-Alanie O M, Mohammed A, Periasamy K, Nicol A, Meek R M D. Anatomical pelvic loading of a monoblock polyethylene acetabular component. Bone Joint J. 2021;103-b(5):872-80.
27. Anderl C, Mattiassich G, Ortmaier R, Steinmair M, Hochreiter J. Peri-acetabular bone remodelling after uncemented total hip arthroplasty with monoblock press-fit cups: an observational study. BMC Musculoskelet Disord. 2020;21(1):652.