PAST AND FUTURE OF ROBOT-ASSISTED SURGERY

Abstract

Computers arrived late in orthopaedic surgery. While the rest of the world already happily integrated computers into daily life, business and production, orthopaedic surgeons remained sceptical and denied any need for help from modern technology. It was in the mid-eighties though, that a young veterinary surgeon from California, specializing in total hip replacement in dogs, was contemplating the problems that he encountered during surgery. This veterinary surgeon, the late Hap Paul, was one of the founding members of the custom – implant society, from which evolved ISTA. He struggled with wrong positioning of implants and broken bones, and wondered why implants that were manufactured with highest technology finally were placed into the bone with crude instruments reminiscent of those found in a carpenters workshop. With the help of IBM and engineers from the University of California he created a system which he called ROBODOC^®, and it became the first computer based system helping the surgeon during an orthopaedic procedure. The technological effort was huge, as many parts of the system and of the procedure using advance robotic tools had to be invented from scratch. There was nothing there they could copy, and the system they invented – an active robot performing a critical part of surgery – represented a very ambitious step forward. Some compare the development of ROBODOC^® with the technological history of the Concorde: very sophisticated technology, very early and very advanced, somewhat expensive and with an aura of vision and adventure

Of course this was not the only and ultimate solution of bringing computers into surgery. Other researchers took a step backwards: they invented systems that helped the surgeon to navigate hand held instruments and implants within the surgical field, so-called navigation systems. These were initially used by neurosurgeons to navigate probes within the brain. As neurosurgeons were closely related to and depending on CT-scan, the logic step was to use the CT- datasets, match them with real world (the process of registration) and create a virtual 3D space that is congruent to the real 3D space. Using CT provided orthopaedic surgeons increase visibility with less required exposure

With the help of optical systems (other options are mechanical or magnetic systems) instruments can be tracked outside and inside the surgical object and allow precise navigation within the surgical field. However, preparation of tissue and/or placement of implants were still done with manual tools. Very early application of this navigation technology was spine surgery in the mid-nineties, where utmost precision was needed during the placement of pedicle screws. Further applications were knee replacement, hip replacement and numerous applications in trauma surgery. Also the source of data was further developed: from the very precise but costly CT-scan to simple radiographs taken during surgery to so-called image free surgery, where data are retrieved directly from the surgical object and approximations are created to direct the placement of implants. Navigation systems, in contrast to the original robotic system, presented two major advantages: they were much cheaper, and they allowed the surgeon to use his standard instruments and, most important, to play a more active part in the surgery, “to stay in the loop” (Tony DiGioia).

Today there are thousands of navigations systems in routine use all over the world. Published results show benefits, but also limits. Surgery using navagation has become more precise and results more reproducible, yet there are still outliers which mainly stem from technical problems, but which are hard to detect and cause significant inaccuracy. Therefore the era of the robots is not over: robotic technology is currently revisited by numerous groups, and technically more advanced robots are developed and currently under testing. Robotic technology has continued to make inroads into the market with demonstrated capacity to assist the surgeon to reduce intraoperative complications, eliminate outliers, and achieve improved surgical outcomes consistently. Different types of robots (active, semi active and passive robots, such as systems which provide for constrained motion in the surgical field) are successfully moving into the operating theatre. ROBODOC^®, the forefather of all computer-assisted orthopaedic systems, is still around and actively applied during surgery, with published good results and high reliability.

The history of ROBODOC^® is a master piece of technological history. After initial successful human surgeries, embedded in the feasibility study required by the FDA, the next step was more difficult: the randomized study for FDA approval to prove the efficacy almost killed the company and with it the technology. In early optimistic statements the inventors foresaw major benefits, but overlooked the difficulties to prove these in the postoperative outcome. Disadvantages of the system, like longer OR times and higher blood loss, at least prevalent in the in the early trials of the FDA study, were obvious while the “clear” benefits in outcome were not so obvious. Thus marketing abroad became a major option, and Europe became the prime target. The attempt was successful, and rapidly 30 systems were busy all over Europe. This development was brought to a halt by a couple of unsubstantiated lawsuits in Germany and unprecedented negative press campaign accompanying this effort. The lawsuits were sponsored by the illusion to finally sue an American company and gain millions from that lawsuit. This process started in the early days of this century, and so far, in spite of numerous sentences proclaimed, not one court has condemned the technology or found any wrong doing in applying it. In parallel with the declining European market, the Asian market was developed, and surgeons there benefited from the experiences in Europe and the consecutive improvements of the system. Currently TKR and THR are routinely performed using the ROBODOC^® system in Japan, Korea and India.

This process let to recovery of the company, which tells us that technological progress also in medicine is inherently coupled to economic success. Although the first system applied in CAOS, Robodoc still is the most advanced system in technological terms. This is finally also accepted by the very critical USFDA, which had problems with the approval for such a long time because the system represents an autonomous robotic system working on patients.

Initial problems like bulkiness, software bugs and invasiveness have been overcome. Work is underway even now to make the system more flexible covering a wider range of surgical procedures like uni and multi compartmental knee, hip resurfacing and acetabular cup in THR and further expanding the functionality of the system supporting not just orthopedic procedures but Neurosurgical procedures as well.

Many of these developments are in the final stages of testing. In the meantime the CAOS community, i.e. the surgeons and engineers primarily working in application and development of the existing systems, more and more become convinced that computer assisted surgery undoubtedly is heading towards the integration of robotic systems into surgery: this is where ROBODOC^® came from.