Enhanced coating
to reduce metal ion release

CONCEPT

Materials commonly used in orthopaedics consist of metal alloys which can release metal ions [1,2]. Metal ions might elicit hypersensitivity reactions and expose the patient to inflammatory states which might lead to implant removal and revision surgery [1, 3, 4].  
Metal hypersensitivity affects about 10% to 15% of the general population, but recent studies report an even more frequent incidence due to the increasing exposure to metals [3]. It is important to consider alternative solutions in orthopaedics to reduce the release of metal ions and potentially reduce the occurrence of related reactions [5].

Enhanced coating to reduce metal ion release

SensiTiN is a ceramic-like coating of titanium nitride, designed to reduce the release of metal ions from Medacta’s implants for knee replacement.
This property makes SensiTiN the preferred choice of most orthopaedic surgeons for treating patients with metal hypersensitivity, and it is also considered a valid means of reducing the likelihood of hypersensitivity onset [6,7,8]

KEY FEATURES

REDUCED METAL ION RELEASE

SensiTiN coating acts as a barrier against the potential release of metal ions, reducing the risk of hypersensitive reactions.
With SensiTiN coating, the release of metal ions is reduced by up to 90% compared to uncoated implants [9].

HIGH ADHESIVE STRENGTH

SensiTiN coating is  applied  through  physical  vapour  deposition (PVD). This process allows the formation of a strong bond between the coating and the implant [4,9].
SensiTiN’s high adhesive strength makes it very resistant to chipping and delamination [9].

 

ENHANCED SURFACE PROPERTIES...

  • HIGHER SURFACE HARDNESS
    SensiTiN coating is up to 4 times harder than conventional CoCrMo alloys.
    It increases the implants’ surface hardness and makes them more resistant to scratches.[9]
  • IMPROVED SURFACE WETTABILITY
    Synovial liquids can better lubricate SensiTiN coated surfaces than uncoated CoCr, indicating a higher wettability that can increase the lubrication between the implant’s articulating surfaces. [9,10]
  • LOW SURFACE ROUGHNESS
    SensiTiN coated implants have very low surface roughness (less than 0.05 μm).[9] 
 

...RESULTING IN WEAR RATE REDUCTION

Laboratory tests have demonstrated that surface properties provided by SensiTiN allow for low wear rates of the polyethylene even when tested in extreme conditions (e.g. in the presence of particles between the articulating surfaces)[9].

PRODUCT RANGE

SensiTiN coating is applied to Medacta’s GMK System, forming a complete system characterized by low metal ion release that makes possible the treatment of a wide number of patients,
from primary to revision cases.

Total Knee Systems

 

Revision Knee Systems
REFERENCES

[1] Hallab N. et al., «Metal Sensitivity in Patients with Orthopaedic Implants», The Journal of Bone and Joint Surgery, vol. 83A, n. 3, pp. 428-436, 2001.
[2] Eftekhary N. et al., «Metal Hypersensitivity in Total Joint Arthroplasty», JBJS Reviews, vol. 6, n. 12, p. e1, 2018.
[3] Haddad S. F. et al., «Exploring the Incidence, Implications and Relevance of Metal Allergy to Orthopaedic Surgeons», Journal of the American Academy of Orthopaedic Surgeons, vol. 3, n. 4, p. e023, 2019.
[4] Malikian R. et al., «Four Station Knee Simulator Wear Testing Comparing Titanium Niobium Nitride with Cobalt Chrome», J Bioengineer & Biomedical Science, vol. 3, n. 3, 2013.
[5] Thienpont E., «Titanium niobium nitride knee implants are not inferior to chrome cobalt components for primary total knee arthroplasty», Arch Orthop Trauma Surg, vol. 135, pp. 1749-1754, 2015.
[6] Bader R. et al., «Alternative materials and solutions in total knee arthroplasty for patients with metal allergy [article in German]», Orthopade, vol. 37, n. 2, pp. 136-142, 2008.
[7] Thomsen M. et al., «Pain in a chromium-allergic patient with total knee arthroplasty: disappearance of symptoms after revision with a special surface coated TKA: a case report», Acta Orthop., vol. 82, n. 3, pp. 386-388, 2011.
[8] Thomsen M. et al., «Use of allergy implants in Germany: results of a survey [article in German]», Orthopade, vol. 42, n. 8, pp. 597-601, 2013.
[9] Medacta: data on file.
[10] Serro A. P. et al., «A comparative study of titanium nitrides, TiN, TiNbN and TiCN, as coatings for biomedical applications», Surface and Coatings Technology, pp. 3701-3707, 2009.

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