**6. Future perspectives**

The arthroplasty surgery practiced today was developed about 50 years ago. It was created in the "analogical era." The rapid transformations that occurred with the fourth industrial revolution, accelerated by the COVID-19 pandemic, led us to live in the "digital age." In this scenario of intensive use of technology and computing in all sectors of human life, it is predictable that arthroplasty will undergo transformations. Some of them are already present, although still timidly, in clinical practice. We list below five technologies that are already available, although still timidly used, and that could lead to significant advances in the near future:

• Computer-assisted surgical navigation

Although there is still no consensus on what would be the ideal alignment of a limb with knee prosthesis, the traditional concept of neutral alignment have being questioned by concepts such as kinematic alignment, the quest for reliable and

reproducible achievement of the intra-operative alignment goal has been the primary motivator for the development of Computer assisted surgical navigation (CASN). There are already a significant number of clinical studies showing that the use of CASN increases the accuracy of the planned alignment [12]. However, there is still a lack of clinical studies demonstrating that the long-term clinical outcome of using CASN is better than traditional alignment without the use of technology. Although the cost of using the equipment has been progressively decreasing over time and with greater use, it will be necessary for the future to improve the system to further reduce the cost of use and enable its use on a large scale. The reader is invited to explore the chapter in this book called "advanced, imageless navigation in contemporary THA: optimizing acetabular component placement" written by Prof Andrew Kurmis.

• Robotic-assisted surgery

As a natural evolution of the use of CASN, robotic systems with mechanical arms associated with the navigation system emerged. Companies such as Zimmer Biomet (Rosa), Stryker (Mako), Smith & Nephew (Cori), for example, already offer orthopedic surgeons the clinical use of robot-assisted prostheses. Current systems include robotic arms, robotic-guided cutting jigs, or robotic milling systems, with different navigation strategies using active, semiactive, or passive control systems [13–15]. One problem is that the robots used in arthroplasties are not very versatile. There are specific systems for hip or knee, some more recent systems already allow using the same robot for both hip and knee, but not for other joints. This greatly increases the cost for the hospital, making the technology even restricted to places with higher purchasing power. For a deeper understanding of the use of robots in arthroplasties, the reader is invited to read the chapter entitled "active robotic total knee arthroplasty" written by Prof. Andrei Gritsyuk.

• Augmented reality

However, in parallel with the development of navigation and robots, the recent digital technological advance (fourth industrial revolution caused by the emergence of the internet) already presents another type of innovative solution to assist the surgeon in the implantation of the prosthesis: the use of the augmented reality (AR). It is stated that AR could provide a more efficient and cost-effective solution than robotic surgery [16].

• Patient-specific implants

The development of new 3D printing technologies made it possible to design patient-specific implants and single-use instruments, which have also been proposed as an alternative technology to improve accuracy, while also improving efficiency and limiting the associated cost of arthroplasties. This technology has the potential of reducing operating room times over reusable sets, and benefit theater personnel ergonomically while presenting potential cost-saving benefits in terms of reduced sterilization costs and surgical times [17].

• Nanotechnology

The future also promises advances not only in systems to aid prosthesis implantation but also in the manufacture and composition of implants. The *Introductory Chapter: Past, Present, and Future of Joint Reconstructive Surgery DOI: http://dx.doi.org/10.5772/intechopen.109545*

reader is invited to visit this book the chapters written by Mr. James Broderick on "Biomaterials in arthroplasty" and Prof. Jörg Lützner on "Modern Coatings in Knee arthroplasty."
