Privacy Policy & Notice to California Residents

MAX Acetabular Inserts Design Rationale

Hip Product Group

Optimized crosslinking for wear resistance

First generation XLPE hip inserts have demonstrated very low wear rates in both hip simulators and in clinical radiographic studies. [1,2,3,4,5,6,7,8,9,10] Researches have found that the optimal radiation dose for improving wear resistance is about 10 Mrad, above which no further beneficial effects are observed. Thus, MAX is irradiated to 10 Mrad XLPE.

Mechanically-annealed, rather than melt-annealed

Currently available XLPE is melt-annealed to eliminate the free radicals that lead to oxidation and subsequent polymer degradation. The reduction in mechanical properties caused by melt-annealing is well-known.

MAX is annealed using a proprietary mechanical compression process. This mechanical annealing eliminates* free radicals—like melt-annealing—but without sacrificing mechanical properties. [11,12]

*With both melt annealing and mechanical annealing, free radicals are eliminated to a level at or near the detection limit of ESR measurement equipment.

  1. Kurtz S, Medel FJ, MacDonald D, Rimnac CM. In vivo oxidation, oxidation potential, and clinical performance of highly crosslinked UHMWPEs implanted for up to 8 years. 4th International Meeting UHMWPE for arthroplasty: From Powder to Debris 2009; Torino, Italy.
  2. Digas G, Karrholm J, Thanner J, Herberts P. 5-year experience of highly cross-linked polyethylene in cemented and uncemented sockets: Two randomized studies using radiostereometric analysis. Acta Orthop 2007; 78(6): 746-54.
  3. D’Antonio JA, Manley MT, Capello WN, et al. Five-year experience with Crossfire highly cross-linked polyethylene. Clin Orthop Relat Res 2005; 441: 143-50.
  4. Engh CA, Stepniewski AS, Ginn SD, et al. A randomized prospective evaluation of outcomes after total hip Arthroplasty using crosslinked marathon and non-cross-linked Enduron polyethylene liners. J Arthroplasty 2006; 21(6): 17-25.
  5. Olyslaegers C, Defoort K, Simon JP, Vandenberghe L. Wear in conventional and highly cross-linked polyethylene cups: a 5-year follow-up study. J Arthroplasty 2008; 23(4): 489-94.
  6. Garcia-Rey E, Garcia-Cimbrelo E, Cruz-Pardos A, Ortega-Chamarro J. New polyethylenes in total hip replacement: a prospective, comparative clinical study of two types of liner. J Bone Joint Surg Br 2008; 90(2): 149-53.
  7. Geerdink CH, Grimm B, Vencken W, Heyligers IC, Tonino AJ. Cross-linked compared with historical polyethylene in THA: An 8-year clinical study. Clin Orthop Relat Res 2009; 467(4): 979-84.
  8. Glyn-Jones S, Isaac S, Hauptfleisch J, McLardy-Smith P, Murray DW, Gill HS. Does highly cross-linked polyethylene wear less than conventional polyethylene in total hip arthroplasty? A doubleblind, randomized, and controlled trial using roentgen stereophotogrammetric analysis. J Arthroplasty 2008; 23(3): 337-43.
  9. Kurtz SM, Medel FJ, MacDonald DW, Parvizi J, Kraay MJ, Rimnac CM. Reasons for revision of first-generation highly cross-linked polyethylenes. J Arthroplasty. 2010 Sep;25(6 Suppl):67-74.
  10. Kurtz SM. Chapter 8 The clinical performance of UHMWPE in knee replacements. In UHMWPE Biomaterials Handbook Second Edition (ed. Kurtz SM). Elsevier: Amsterdam, 2009.
  11. Bhattacharyya S, Matrisciano L, Spiegelberg S, Harris W, Muratoglu O. Mechanical elimination of residual free radicals in an irradiated UHMWPE rod: advantages over melting. 50th annual meeting of the orthopaedic research society. 2004:1474.
  12. Gomez-Barrena E, Medel F, Puertolas JA. Polyethylene oxidation in total hip arthroplasty: evolution and new advances. The Open Orthopedics Journal 2009; 3:115-120.