Surfaces of medical implants can be enhanced with the favorable properties of titanium-nitride (TiN). In a review of English medical literature, the effects of TiN-coating on orthopaedic implant material in preclinical studies were identified and the influence of these effects on the clinical outcome of TiN-coated orthopaedic implants was explored. The TiN-coating has a positive effect on the biocompatibility and tribological properties of implant surfaces; however, there are several reports of third body wear due to delamination, increased ultrahigh molecular weight polyethylene wear, and cohesive failure of the TiN-coating. This might be due to the coating process. The TiN-coating process should be optimized and standardized for titanium alloy articulating surfaces. The clinical benefit of TiN-coating of CoCrMo knee implant surfaces should be further investigated.
Titanium-nitride (TiN) is a ceramic which has general properties such as great hardness (2000 kg/mm2), high decomposition temperature (2949°C), defect structure, that is, deviation from stoichiometry, chemical stability at room-temperature, superconductivity, and a gold-yellow color [
TiN is mainly used as a coating to enhance other materials with the properties of TiN. TiN showed encouraging blood tolerability properties with a hemolysis percentage near to zero [
In 1972, Steinemenan patented the “use of implants of titanium or a titanium alloy for the surgical treatment of bones” [
Untreated titanium-aluminum-vanadium alloy (Ti6Al4V) showed excessive wear of femoral heads, and surface treatment of Ti6Al4V by TiN-coating was discussed as a possibility to enhance the Ti6Al4V surface [
This study focuseson preclinical and clinical studies using TiN-coated orthopaedic implants and implant material. Inclusion criteria were clinical studies on TiN-coated orthopaedic implants and preclinical studies on wear and biocompatibility of TiN-coated implant material. To identify all relevant studies on TiN-coated orthopaedic implants and implant material in English scientific literature, the following databases were searched: Medline (1947 to January 2015), Embase Classic and Embase (1947 to January 2015). No restrictions were made to the type of studies. Papers outside the English language, abstracts from scientific meetings, and unpublished reports were excluded. References of retrieved publications were used to add studies meeting the inclusion criteria that were missed by the electronic search. The Medline search is defined in Appendix. The query was checked for inconsistencies using PubMed Query Editor 0.1. Selection of studies was first performed by screening titles and abstracts. In case of insufficient information in the title or abstract, full text copies were retrieved to make a decision for the article selection. References of retrieved publications were used to add studies meeting the inclusion criteria that were missed by the electronic search.
The results of the combined Medline and Embase search are shown in Figure
Flow diagram of the search process. Duplicate studies were excluded as well as studies of which there was no abstract. Studies on cardiovascular, dental, and neurological titanium-nitride coated implant material and other studies were excluded. Four studies on dental titanium-nitride coated implant material were included in this study in Section
A high variety of cell types were used for cell culture on TiN-coated implant materials: human bone marrow stem cells [
Preclinical studies on proliferation and differentiation of cells cultured on TiN-coated materials compared with control material.
Study | Cell type | TiN-coated material | Proliferation | Differentiation |
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van Raay et al. (1995) [ |
Human fibroblasts | Glass cover slips | ~ | |
Groessner-Schreiber et al. (2003) [ |
Mouse fibroblasts | cpTi | + | |
Yeung et al. (2007) [ |
Mouse osteoblasts | NiTi; SS; Ti6Al4V | + | |
Annunziata et al. (2008) [ |
BMSC | Ti6Al4V | ~ | ~ |
Annunziata et al. (2011) [ |
BM-MSC | TPS | ~ | ~ |
Czarnowska et al. (2011) [ |
Saos-2 | Ti6Al4V | ~ | ~ |
Durual et al. (2011) [ |
hOB | cpTi | + | ~ |
Gordin et al. (2012) [ |
hFOB 1.19 | cpTi; Ti6Al4V | ~ | |
Rieder et al. (2012) [ |
hOB | cpTi; SS | + | ~ |
van Hove et al. (2013) [ |
MC3T3-E1 | CoCrMo | + | ~ |
~: no difference between TiN-coated material and the control; +: higher on TiN-coated material than the control; −: lower on TiN-coated material than the control. TiN: titanium-nitride; BMSC: human bone marrow stromal cells; BM-MSC: human bone marrow mesenchymal stem cells; Saos-2: sarcoma osteogenic, human osteoblast-like cells; hOB: human primary osteoblasts; hFOB 1.19: human fetal-osteoblastic cell line; MC3T3-E1: mouse calvarial osteoblast-like cell; cp Ti: commercially pure titanium; NiTi: nickel-titanium; SS: stainless steel; Ti6Al4V: titanium-aluminum-vanadium alloy; TPS: titanium plasma sprayed.
TiN-coated materials were implanted in the femurs of dogs [
Results of three independent experiments showed a lower adhesion and proliferation (
TiN-coated Ti6Al4V showed a high scratch resistance [
Preclinical studies on wear of TiN-coated materials compared with control material.
Study | Test | TiN-coated material | TiN-coating process | Control | Findings | TiN-coating related problems |
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Coll and Jacquot (1988) [ |
UHMWPE pin on disc | Ti6Al4V | AVID | Ti6Al4V | Reduction of UHMWPE wear |
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Maurer et al. (1993) [ |
Screws on plates | Ti6Al4V | PVD/PIII/NII | Ti6Al4V | Reduction of weight loss and metal release |
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Venugopalan et al. (2000) [ |
Pin-cylinder scratch test | Ti6Al4V | N | Ti6Al4V | Better scratch resistance |
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Hendry and Pilliar (2001) [ |
Fretting test | Ti6Al4V | PVD | Ti6Al4V | No evidence of significant wear |
Microparticles and pinholes |
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Komotori et al. (2001) [ |
Multidirectional scratch testing | Ti6Al4V/SP-700 | AIP | TO-Ti6Al4V/SP-700 | More mechanical damage |
Adhesive coating failure; pitting and blistering |
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Fisher et al. (2002) [ |
MOM hip simulator | CoCrMo | AEPVD | CoCrMo | Lower wear |
Relatively high wear inserts |
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Williams et al. (2003) [ |
Multidirectional pin on plate | CoCrMo | AEPVD | CoCrMo | Fourfold increase of wear |
Cohesive failure |
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Gutmanas and Gotman (2004) [ |
UHMWPE hip simulator | cpTi/Ti6Al4V | PIRAC | SS | Lower UHMWPE wear rate |
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Fisher et al. (2004) [ |
MOM hip simulator | CoCrMo | AEPVD | CoCrMo | Lower wear |
Some localized damage |
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Galvin et al. (2008) [ |
UHMWPE hip simulator | CoCrMo | AEPVD | CoCrMo | Higher UHMWPE volumetric wear rate |
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Galetz et al. (2010) [ |
Station-wheel-on-flat testing | CoCrMo | PVD | CoCrMo | No scratches |
Polyethylene in pinholes |
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Kim et al. (2010) [ |
Pin on disc | Ti6Al4V | AIP | Ti6Al4V | Lower wear |
Higher wear of TiN compared with TiAlN |
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Lee et al. (2010) [ |
UHMWPE pin on disc | SS | PIII | CoCrMo | Lower UHMWPE volumetric wear rate |
In a metal-on-metal hip simulator test, TiN-coated CoCrMo showed a lower wear rate compared with uncoated CoCrMo [
Clinical studies on survival of TiN-coated orthopaedic implants are presented in Table
Clinical studies on survival of TiN-coated orthopaedic implants.
Study | Type | Prosthesis | TiN-coated material | Number | Fixation | Follow-up | Survival | Reasons for revision |
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Buechel and Pappas (1992) [ |
Cohort | TAP | Ti6Al4V | 14 | Cementless | 15 (5–24) | 100% | None |
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Massoud et al. (1997) [ |
Cohort | THP | Ti nos | 16 | Cemented | 26 | 56% | Aseptic loosening |
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Buechel et al. (2003) [ |
Cohort | TAP | Ti6Al4V | 50 | Cementless | 60 (24–120) | 93.5% | Malalignment; PE wear; component subsidence |
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Buechel et al. (2004) [ |
Cohort | THP | Ti6Al4V | 130 | Cementless | 77 (27–134) | 95.5% | Aseptic loosening; bearing dissociation |
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Buechel and Pappas (2011) [ |
Cohort | RHP | Ti6Al4V | 60 | Cementless | 36 (8–70) | 91.8% | Not specified |
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Mohammed et al. (2014) [ |
Cohort | TKP | CoCrMo | 305 | Cementless | 79 (36–122) | 95.1% | Prosthetic fractures; aseptic loosening; alignment |
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van Hove et al. (2015) [ |
RCT | TKP | CoCrMo | 50 | Cementless | 60 | 96% | Aseptic loosening |
All prosthetic joint articulations were TiN-coated implant material to UHMWPE. Follow-up is presented as mean (range) in months. RCT: randomized clinical trial; TAP: total ankle prosthesis; THP: total hip prosthesis; RHP: resurfacing total hip prosthesis; TKP: total knee prosthesis; Ti6Al4V: titanium-aluminum-vanadium alloy; CoCrMo: cobalt-chromium-molybdenum alloy; Ti nos: titanium not otherwise specified.
In a postmortem retrieval analysis of a cementless TiN-coated Ti6Al4V THA one year after index surgery, the TiN-coated Ti6A14V femoral head showed circular voids without TiN-coating and voids filled with circular droplets of pure titanium [
Failures of a cementless TiN-coated titanium alloy-on-UHMWPE resurfacing THA were suggested to be due to the use of conventional UHMWPE instead of highly cross-linked UHMWPE [
In the radiological follow-up (16.6 months, range 12–39 months) of 330 hips with a press-fit polyethylene cup with TiN-coated stainless steel mesh (Sulmesh, Sulzer, Winterthur, Switzerland) for the bone-implant interface, there was one case showing a radiolucent line around the cup; however, this was without clinical problems [
In a retrospective study of mainly cementless TiN-coated CoCrMo mobile bearing TKAs, revision surgery was performed in 4.9% [
In a recently published RCT, no differences in postoperative pain, KSS, revision surgery, knee flexion and knee flexion contracture, knee circumference, and knee skin temperature were observed between the TiN-coated CoCrMo TKA (
In preclinical studies, TiN-coating of implant materials showed to be biocompatible with mainly favorable tribological properties. Several cohort studies of TiN-coated implants showed an overall survival exceeding 90% with a follow-up of 15 to 77 months and good clinical results [
In a pins-and-plate test of polished PVD TiN-coated CoCrMo a higher surface roughness, catastrophic cohesive failure within the layers of the TiN-coating and a fourfold increase in wear was found [
A high incidence of aseptic loosening was found with a new design of cemented THA using CoCrMo and TiN-coated titanium heads on UHMWPE liner [
Prosthetic fractures of the medial flange of size 5 right-sided TiN-coated CoCrMo femoral component of a TKA were found [
Noteworthy is that of the 7 clinical studies, case reports not included, 4 studies [
Titanium alloys used for articulating surfaces require surface treatment to increase hardness and reduce wear. TiN-coating has a favorable effect on the biocompatibility and tribological properties of implant surfaces. However, there are reports of third body wear due to delamination of the PVD TiN-coating on Ti6Al4V, increased UHMWPE wear and cohesive failure of the PVD TiN-coating on CoCrMo of hip implants in preclinical studies, and TiN-coating breakthrough and fretting in a retrieval study of TiN-coated Ti6Al4V femoral heads. These adverse effects might be related to the various coating processes of titanium alloys. The TiN-coating process of titanium alloy articulating surfaces should be optimized and standardized. There were no reports of adverse effects related to TiN-coating of CoCrMo knee implants. Clinical benefit of TiN-coating of CoCrMo knee implant articulating surfaces should be investigated further.
Pubmed/Medline Search strategy: (((((((“shoulder”[MeSH Terms] OR “shoulder”[Tiab]) AND (“prosthesis implantation”[MeSH Terms] OR (“prosthesis”[Tiab] AND “implantation”[Tiab]) OR “prosthesis implantation”[Tiab] OR “prosthesis”[Tiab] OR “prostheses and implants”[MeSH Terms] OR (“prostheses”[Tiab] AND “implants”[Tiab]) OR “prostheses and implants”[Tiab])) OR ((“shoulder”[MeSH Terms] OR “shoulder”[Tiab]) AND (“arthroplasty”[MeSH Terms] OR “arthroplasty”[Tiab]))) OR ((“shoulder”[MeSH Terms] OR “shoulder”[Tiab]) AND (“replantation”[MeSH Terms] OR “replantation”[Tiab] OR “replacement”[Tiab]))) OR ((“hip prosthesis”[MeSH Terms] OR (“hip”[Tiab] AND “prosthesis”[Tiab]) OR “hip prosthesis”[Tiab] OR “arthroplasty, replacement, hip”[MeSH Terms] OR (“arthroplasty”[Tiab] AND “replacement”[Tiab] AND “hip”[Tiab]) OR “hip replacement arthroplasty”[Tiab] OR (“hip”[Tiab] AND “prosthesis”[Tiab])) OR ((“hip”[MeSH Terms] OR “hip”[Tiab]) AND (“arthroplasty”[MeSH Terms] OR “arthroplasty”[Tiab])))) OR ((“arthroplasty, replacement, knee”[MeSH Terms] OR (“arthroplasty”[Tiab] AND “replacement”[Tiab] AND “knee”[Tiab]) OR “knee replacement arthroplasty”[Tiab] OR (“knee”[Tiab] AND “arthroplasty”[Tiab]) OR “knee arthroplasty”[Tiab]) OR (“knee prosthesis”[MeSH Terms] OR (“knee”[Tiab] AND “prosthesis”[Tiab]) OR “knee prosthesis”[Tiab] OR “arthroplasty, replacement, knee”[MeSH Terms] OR (“arthroplasty”[Tiab] AND “replacement”[Tiab] AND “knee”[Tiab]) OR “knee replacement arthroplasty”[Tiab] OR (“knee”[Tiab] AND “prosthesis”[Tiab])))) OR ((“ankle”[MeSH Terms] OR “ankle”[Tiab] OR “ankle joint”[MeSH Terms] OR (“ankle”[Tiab] AND “joint”[Tiab]) OR “ankle joint”[Tiab]) AND (“arthroplasty”[MeSH Terms] OR “arthroplasty”[Tiab])) OR (“ankle”[MeSH Terms] OR “ankle”[Tiab] OR “ankle joint”[MeSH Terms] OR (“ankle”[Tiab] AND “joint”[Tiab]) OR “ankle joint”[Tiab]) AND “prosthesis implantation”[MeSH Terms] OR (“prosthesis”[Tiab] AND “implantation”[Tiab]) OR “prosthesis implantation”[Tiab] OR “prosthesis”[Tiab] OR “prostheses and implants”[MeSH Terms] OR “prostheses”[Tiab]) AND ((ti2n[Tiab] OR TiNi[Tiab]) OR (“titanium nitride”[Tiab] AND coating[Tiab])) OR “titanium nitride”[Tiab].
The authors declare that there is no conflict of interests regarding the publication of this paper.
The authors would like to thank W. Salemink for her valuable assistance with the search of the literature.