A Bibliometric Analysis and Visualisation of Research Trends in Titanium-Based Orthopaedic Implants

Titanium is one of the widely used metal for orthopaedic implants. The bibliometric analysis had been conducted to understand the active authors, organizations, journals, and countries involved in the research domain of “Titanium-based orthopaedic implants”. All published articles related to “Titanium-based orthopaedic implants” from “Scopus”, were analyzed using the VOS viewer to develop analysis tables and visualization maps. This article had set the objective to consolidate the scientific literature regarding “Titanium-based orthopaedic implants” and also to find out the trends related to the same. The most active journal related to this research domain was Biomaterials. The most active country was the United States of America. The leading organization engaged in research regarding Titanium Based orthopaedic implants was the Brown University of the United States of America and the Chinese Academy of Sciences of China. The most active authors who had made valuable contributions related to orthopaedic implants were Webster T.J.


Introduction
An engineered medical device to replace a missing or damaged joint or bone is known as an orthopaedic implant. Various types of orthopaedic implants and practices are widely used in the medical world. Wear and corrosion od orthopaedic implants ultimately lead to poor performance, pain, and wastage of money. Similarly, various types of surface treatments and surface coatings can be conducted on orthopaedic implants to improve their competency to be used as a material for orthopaedic-implants. Patient-specific orthopaedic implants are the trends of the day and can improve the performance and reduce the cost of implant (Haglin et al., 2016). Infections of biomaterials are common and are highly dangerous (Nuswantoro et al., 2020).
Titanium is one of the widely used metal for orthopaedic implants. Moreover, Nanostructured titanium is an ideal material for improving orthopaedic implants (Durmus and Webster, 2012). Titanium is ideal for the growth of bioactive surfaces on orthopaedic implants (Gil et al., 2002). There are various developments in material engineering and surface engineering, which can play a significant role in the development of new types of orthopaedic implants; and in enhancing the performance of orthopaedic implants. Bioactive coats on titanium implants can improve biocompatibility of titanium compounds for orthopaedic implants (Karlov et al., 1998).; similarly Ceramic coatings on the high-strength titanium as a prospective material for orthopaedic implants (Karlov et al., 2001); the anti-biofilm activity of a new bioactive glass coating on titanium implants (Marques et al., 2020); Electrophoretic deposition performance of hydroxyapatite coating on titanium alloys for orthopaedic implant application (Nuswantoro et al., 2020). Some latest researches had come up with wear-resistant titanium-ceramic composites for orthopaedic implant devices This bibliometric analysis will be a useful platform for future researchers by realizing the top researchers, organizations, and countries involved in research regarding Titanium-based orthopaedic implants. This article is arranged into four sections. The first section is the introduction, followed by the discussion of the methodology by which the research was conducted. The third section deals with results and discussion. The fourth section deals with the conclusion. The following research objectives and research questions were framed for conducting bibliometric analysis systematically. c) Which are the main journals related to Titanium-based orthopaedic implants?

Research Methodology
Scopus files had been used for this article. For the article selection, the Boolean used was TITLE-ABS (Titanium "orthopaedic implants") on 12/03/2021. All the tables in this paper were created by using Microsoft Excel and VOS Viewer. Grammarly was used for spelling and grammar checks. Mendeley was used for article review and citation. This paper had been inspired by bibliometric analysis in its presentation style, analysis, and methodology from the works (Farhat et

Results and discussion 3.1 Results
This first round of search produced an outcome of 1282 documents, in 8 languages, out of which 1242 documents were in English. The classification of document categories is shown in Figure 1. For improving the quality of the analysis, we had selected only the peer-reviewed articles and all other documents had not been considered. Thus after using filters "Article" and "English" the second round search produced an outcome of 932 English articles (both open access and others). This paper had used all English articles to conduct bibliometric analysis and visualization using VOS Viewer. The English research articles in this domain since 1970 had been shown in Figure 2.    In Co-occurrence analysis, we had used all keyword analyses, by keeping the minimum number of occurrences of a keyword as 100. This combination plotted the map of 41 thresholds, in three clusters. The overlay visualization of co-occurrence analysis of keywords has been shown in Figure 4.  Co-authorship analysis of the countries engaged in the research on "Titanium-based orthopaedic implants" had been shown in Figure 5. The overlay visualization map of co-authorship analysis plotted in Figure 5, points out the main countries with their strong co-authorship linkages and clusters involved.  The most active countries in this research domain were the United States of America with the highest number of publications, co-authorship links, and citations.
Link analysis and citation analysis were used to identify the most active journal in this research domain. We have taken the parameters of the minimum number of documents of a journal as one and the minimum number of citations of a journal as one for the link analysis and citation analysis. Highlights of the most active and relevant journals related to "Titanium-based orthopaedic implants" are shown in table 4. Table 4 shows the journal activity of this research domain through parameters of publication volume, citations, and co-authorship linkages. From the above discussion regarding the bibliometric patterns in the research regarding Titanium Based orthopaedic implants, this research had observed a gradual increase in research interest regarding Titanium Based orthopaedic implants from the starting of the millennium and the momentum is going on positively. This points out the relevance and potential of this research domain (Refer to Figure 2). The most active author in this research domain was Webster T.J with the highest publication, co-authorship links, and citations (Refer to table 1). The overlay analysis of top countries researching Titanium Based orthopaedic implants indicates that the United States of America was the leading country relating to the highest number of publications citations, co-authorship links (Refer to figure 5). The top journal of this research domain was identified as Biomaterials. Researchers can focus on top journals where they can identify the most relevant and highly cited articles regarding Titanium Based orthopaedic implants.

Conclusion
The Titanium Based orthopaedic implants was an interesting research domain and the most active journal related to this research domain was Biomaterials. The most active country was the United States of America. The leading organization engaged in research regarding Titanium Based orthopaedic implants was the Brown University of the United States of America and the Chinese Academy of Sciences of China. The most active authors who had made valuable contributions related to orthopaedic implants were Webster T.J. This research domain offers a new avenue for researchers and future research can be on Titanium-based implants.