Purpose. Various alignment philosophies for total knee arthroplasty (TKA) have been described, all striving to achieve excellent long-term implant survival and good functional outcomes. In recent years, in search of higher functionality and patient satisfaction, a shift towards more patient-specific alignment is seen. Robotics is the perfect technology to tailor alignment. The purpose of this study was to describe ‘inverse kinematic alignment’ (iKA) technique, and to compare clinical outcomes of patients that underwent robotic-assisted TKA performed by iKA versus adjusted mechanical alignment (aMA). Methods. The authors analysed the records of a consecutive series of patients that received robotic assisted TKA with iKA (n=40) and with aMA (n=40). Oxford Knee Score (OKS) and satisfaction on a visual analogue scale (VAS) were collected at a follow-up of 12 months. Clinical outcomes were assessed according to patient acceptable symptom state (PASS) thresholds, and uni- and multivariable linear regression analyses were performed to determine associations of OKS and satisfaction with 6 variables (age, sex, body mass index (BMI), preoperative hip knee ankle (HKA) angle, preoperative OKS, alignment technique). Results. The iKA and aMA techniques yielded comparable outcome scores (p=0.069), with OKS respectively 44.6±3.5 and 42.2±6.3. VAS Satisfaction was better (p=0.012) with iKA (9.2±0.8) compared to aMA (8.5±1.3). The number of patients that achieved OKS and satisfaction PASS thresholds was significantly higher (p=0.049 and p=0.003, respectively) using iKA (98% and 80%) compared to aMA (85% and 48%). Knees with preoperative varus deformity, achieved significantly (p=0.025) better OKS using iKA (45.4±2.0) compared to aMA (41.4±6.8). Multivariable analyses confirmed better OKS (β=3.1; p=0.007) and satisfaction (β=0.73; p=0.005) with iKA. Conclusions. The results of this study suggest that iKA and aMA grant comparable clinical outcomes at 12-months follow-up, though a greater proportion of knees operated by iKA achieved the PASS thresholds for OKS and satisfaction. Notably. in knees with preoperative varus deformity, iKA yielded significantly better OKS and satisfaction than aMA

Introduction. Technology in Orthopaedic surgery has become more widespread in the past 20 years, with emerging evidence of its benefits in arthroplasty. Although patients are aware of benefits of conventional joint replacement, little is known on patients' knowledge of the prevalence, benefits or drawbacks of surgery involving navigation or robotic systems. Materials & Methods. In an outpatient arthroplasty clinic, 100 consecutive patients were approached and given questionnaires to assess their knowledge of Navigation and Robotics in Orthopaedic surgery. Participation in the survey was voluntary. Results. 98 patients volunteered to participate in the survey, mean age 56.2 years (range 19–88; 52 female, 46 male). 40% of patients thought more than 30% of NHS Orthopaedic operations involved navigation or robotics; 80% believed this was the same level or less than the private sector. A third believed most of an operation could be performed independently by a robotic/navigation system. Amongst perceived benefits of navigation/robotic surgery was more accurate surgery(47%), quicker surgery (50%) and making the surgeon's job easier (52%). 69% believed navigation/robotics was more expensive and 20% believed it held no benefit against conventional surgery, with only 9% believing it led to longer surgery. Almost 50% would not mind at least some of their operation being performed with use of robotics/navigation, with a significantly greater proportion of these coming from patients aged under 50 years. Conclusions. Although few patients were familiar with this new technology, there appeared to be a strong consensus it was quicker and more accurate than conventional surgery. Many patients appear to believe navigation and robotics in Orthopaedic surgery is largely the preserve of the private sector. This study demonstrates public knowledge of such new technologies is limited and a need to inform patients of the relative merits and drawbacks of such surgery prior to their more widespread implementation

The use of robotics in arthroplasty surgery is expanding rapidly as improvements in the technology evolve. This article examines current evidence to justify the usage of robotics, as well as the future potential in this emerging field.

Background

Despite the success of total hip arthroplasty (THA), there are still challenges including restoration of leg length, offset, and femoral version. The Tsolution One combines preoperative planning with an active robotic system to assist in femoral canal preparation during a THA.

Surgical instrumentation for total knee arthroplasty has improved the accuracy, reproducibility and reliability of the procedure. In recent years, minimally invasive surgery introduced instrumentation that was reduced in size to fit within the smaller operative field; with this move the impact and influence of technology became proportionately larger. The introduction of computer navigation is an attempt to improve the surgeon’s visibility in a limited operative field, improve the position of the resection guides, and ultimately the position of the final components.

While it may be appealing to rely on computer navigation to perform a TKA, it is not artificial intelligence and does not make any of the surgical decisions. The procedure still is surgeon directed with navigation serving as a tool of confirmation with the potential for improvements in surgical accuracy and reproducibility. The accuracy of TKA has always been dependent upon the surgeon’s judgment, experience, ability to integrate images, utilize pre-operative radiographs, knowledge of anatomic landmarks, knowledge of knee kinematics, and hand eye co-ordination. Recent advances in medical imaging, computer vision and patient specific instrumentation have provided enabling technologies, which in a synergistic manner optimize the accurate performance of the surgery. The successful use of this technology requires that it not replace the surgeon, but support the surgeon with enhanced intra-operative feedback, integration of pre-operative and intra-operative information, and visual dexterity during the procedure. In developing smart tools or robotic systems, the technology must be: safe; accurate; compatible with the operative field in size and shape, as well be able to be sterilized; and must show measurable benefits such as reduced operative time, reduced surgical trauma and improved clinical outcomes. Advocates believe this is attainable and robotic assisted TKA can achieve levels of accuracy, precision and safety not accomplished by computer assisted surgery.

Smart instruments and robotic surgery are helping us take the next step into the operating room of the future. The role of robots in the operating room has the potential to increase as technology improves and appropriate applications are defined. Joint replacement arthroplasty may benefit the most due to the need for high precision in placing instruments, aligning the limb and implanting components. In addition, this technology will reduce the number of instruments needed for the procedure potentially further improving efficiency in the operating room. As technology advances, robots may be commonplace in the surgical theater and potentially transform the way total knee arthroplasty is done in the future. Robotic surgery and smart tools are new innovative technologies and it will remain to be seen if history will look on its development as a profound improvement in surgical technique or a bump on the road to something more important.

Robotic technology in adult reconstruction – initially the placement of the stem during THR – was introduced in the early nineties of last century, starting in the US. The underlying technology dated back to the year 1986. Because of regulatory restrictions the technology could not spread in the US, but was exported to Europe in 1994. There the technology – primarily distributed in Germany – had a great success and by the year 2000 roughly 50 centers were using Robodoc – the first robot on the market – and a very similar German competitor’s product, CASPAR.

The initial robot was a crude machine, basically the unchanged beta version. Cumbersome fixation, a registration process using three fiducials, the requirement for second surgery to place the fiducials, and last but not least raw and hardly elaborated cutting files made surgery with Robodoc a demanding undertaking. Yet feedback from the surgeons, sometimes vigorously expressed during regular user meetings, let to continuous evolution of the system and resulted in an advanced and stable technology. Also training – with important input from the already experienced sites – improved significantly, which can best be demonstrated by procedure time for first surgery: in Frankfurt 1994 roughly four hours, while today first surgeries at new sites rarely exceed two hours. Further applications – revision surgery, total knee replacement – helped to justify the significant investment into the system.

While robotic technology underwent evolution, other related technologies were developed and entered the market. Main products were the navigation systems, which initially were developed for neurosurgery and spine surgery and which, due to easier handling and lower costs, found more acceptance on behalf of the surgeons. Although the navigation technology in some regards is a step back from the robotic technology, it appealed for just that reason: the surgeon stays in the loop. The surgeon uses the traditional instruments, and the navigator helps him to achieve precision in reaming or placement of implants. In orthopaedic surgery navigators became very popular in TKR, but also in THR.

Another development, completely unrelated to the mentioned technology, presented a new challenge: minimal invasive surgery. While in knee surgery the introduction of arthroscopy in the late seventies already proved the feasibility of minimal invasive techniques, adult reconstruction remained the domain of sometimes aggressive and robust surgery. Only recently minimal invasive procedures were introduced and standardized for a couple of applications. It is important to stress the fact that the term ‘minimal invasive’ did not relate to the size of skin incision only, but to the overall degree of soft tissue damage necessary to prepare for and place the implants. Some companies now offer new instruments allowing for very minimal incisions and reduced soft tissue compromise. In contrast to this development robot assisted surgery remained – in spite of numerous improvements – a rather invasive piece of surgery. These separate developments – navigators and minimal invasive surgery – made robot assisted joint surgery in the eyes of many potential users a rather outdated, superfluous and expensive type of technology. It is therefore time to revisit the original intentions that let to the development of robot assisted surgery.

The original ideas were sponsored by veterinary surgeons specializing in cementless THR for dogs. They experimented with custom implants, but they identified two fields of concerns: fractures and poor placement. Both problems are – still – common in human THR. Robot-assisted surgery was supposed to mainly address these problems. Another asset of robot-assisted surgery is seen in machine milling, which was invented as part of the robotic procedure and which turned out to be superior to conventional reaming.

The published results of robot-assisted THR (i.e. Nishihara et al, 2006) prove that these requirements were met. In our own series in Spain we had no fracture and every single implant was seated according to the preoperative plan. Animal experiments allowing for histological examination of the bone-implant interface showed the uncompromised cancellous scaffolding supporting the implant, while hand-reamed interfaces showed signs of destruction and atrophy.

On the other hands there are concerns that current minimal invasive approaches do cause problems in these regards: control of position is mainly feasible by use of intraoperative x-ray, and fractures do occur.

Therefore robot-assisted surgery seems to be the ideal complement for the minimal invasive approach. The deficits of MIS regarding orientation and visualization of the surgical object can be compensated by the robots proven ability to execute preoperative established plans. The challenge is the current invasiveness of robotic surgery, which – as primary tests and studies show – can be easily accounted for.

In conclusion there is an ever increasing role for robot-assisted surgery in adult reconstruction. It is up to the surgeons to define the requirements and ask for specifications that will meet their and the patient’s expectations regarding the degree of invasiveness involved.

Introduction:

Unicompartmental knee arthroplasty has been shown to have lower morbidity, quicker rehabilitation and more normal kinematics compared to conventional TKA, but subchondral defects, or severe osteoarthritic changes, of the medial compartment may complicate component positioning. Successful UKA in these patients requires proper planning and exact placement of the components to ensure adequate and stable fixation and proper postoperative kinematics. This study presents a series of three patients with spontaneous osteonecrosis of the knee receiving a UKA with CT-based haptic robotic guidance.

There is an increasing prevalence of haptic devices in many engineering fields, especially in medicine and specifically in surgery. The stereotactic haptic boundaries used in Computer Aided Orthopaedic Surgery Unicomparmental Knee Arthroplasty (CAOS UKA) systems for assistive milling control can lead to an increase in the force required to manipulate the device; this study presented here has seen a several fold increase in peak forces between haptic and non-haptic conditions of a semi-active preoperative image system.

Orthopaedic Arthroplasty surgeons are required to apply forces ranging from large gripping forces to small forces for delicate manipulation of tools and through a large range of postures. There is also a need for surgeons to move around and position themselves to gain line of sight with the object of interest and to operate while wearing additional clothing such as the protective headwear and double gloves. These factors further complicate comparison with other ergonomic studies of other robotics systems. While robotics has been implemented to reduce fatigue in surgery one area of concern in CAOS is localised user muscle fatigue in high volume use.

In order to create the conditions necessary for the generation of fatigue in a realistic user experience, but in the time available for the participants, an extended period of controlled and prolonged cutting and manipulation of the robotic arm was needed. This pragmatic test requirement makes the test conditions slightly artificial but does indicate areas of high potential for fatigue when interacting with the system in high volume instances.

The surgeon-robotic system interaction was captured using 3 dimensional motion analysis and a force transducer embedded in the end effector of the robotic arm and modelled using an existing upper body model in Anybody software. The kinematic and force information allowed initial calculations of the interaction between the user and the Robotic system. Validation of the model was conducted using Electromyography assessment of activity and fatigue. Optimisation of the model sought to create an efficient cutting regime to reduce cutting time with reduced muscle force in an attempt to reduce users discomfort/fatigue while taking into account anthropometric variations in the users and minimising overall energy requirements, burr path length and maximum muscle force.

From the assessment of a small group of three surgeons with experience of the Robotic system there was little to no experience of above normal localised fatigue during small volume use of the system. Observation of these surgeons operating the robot state otherwise with examples of reactions to discomfort. There is also anecdotal evidence that fatigue becomes more problematic in higher volume work loads.

Robotic systems for computer assisted surgery have gained a lot of initial interest and several systems to support surgical inventions have been developed over the past ten years. While almost all systems are tailored to specific applications, the technology used may be divided into different groups. One part of the proposed solutions is essentially based on industrial robots, whereas the part relies on specific designs for medical applications. A particular approach which will not be discussed in this contribution is represented by tele-manipulator systems like the daVinci system from Intuitive Surgical Inc. for cardiac applications, and robots for endoscope guidance in abdominal surgery. The operation of these systems is controlled manually by the surgeon based on the visual information of the operating area which he gets by endoscopic cameras.

Robotic application in computer assisted surgery, in contrast to tele-manipulator approaches, is based on pre-operative planning and intra-operative registration of the patient anatomy. They principally offer additional advantages compared to pure navigation systems, such as

No problems due to tremor or unintentional slipping of the tool. Surgery will exactly achieve pre-operatively planned targets, resulting in very good reproducibility

It is a major challenge for new solutions of surgical robot system to exploit this potential while avoiding the drawbacks some existing designs which have not gained wider clinical acceptance. The “added value” of robotic systems must be obvious. Important features to achieve this objectives include interactive operating modes which turn the robot into a powerful and versatile assistance system instead of fully automatic system operation.

Aims

Implant waste during total hip arthroplasty (THA) represents a significant cost to the USA healthcare system. While studies have explored methods to improve THA cost-effectiveness, the literature comparing the proportions of implant waste by intraoperative technology used during THA is limited. The aims of this study were to: 1) examine whether the use of enabling technologies during THA results in a smaller proportion of wasted implants compared to navigation-guided and conventional manual THA; 2) determine the proportion of wasted implants by implant type; and 3) examine the effects of surgeon experience on rates of implant waste by technology used.

Abstract

Robotic-assisted total knee arthroplasty (TKA) has proven higher accuracy, fewer alignment outliers, and improved short-term clinical outcomes when compared to conventional TKA. However, evidence of cost-effectiveness and individual superiority of one system over another is the subject of further research. Despite its growing adoption rate, published results are still limited and comparative studies are scarce. This review compares characteristics and performance of five currently available systems, focusing on the information and feedback each system provides to the surgeon, what the systems allow the surgeon to modify during the operation, and how each system then aids execution of the surgical plan.

Cite this article: Bone Jt Open 2023;4(1):13–18.

Aims

To report the development of the technique for minimally invasive lumbar decompression using robotic-assisted navigation.

Aims

The aim of this study was to report patient and clinical outcomes following robotic-assisted total knee arthroplasty (RA-TKA) at multiple institutions with a minimum two-year follow-up.

Aims

The aim of this study was to compare robotic arm-assisted bi-unicompartmental knee arthroplasty (bi-UKA) with conventional mechanically aligned total knee arthroplasty (TKA) in order to determine the changes in the anatomy of the knee and alignment of the lower limb following surgery.

Introduction. Robotics have been applied to total knee arthroplasty (TKA) to improve surgical precision in component placement and joint function restoration. The purpose of this study was to evaluate prosthetic component alignment in robotic arm-assisted (RA)-TKA performed with functional alignment and intraoperative fine-tuning, aiming for symmetric medial and lateral gaps in flexion/extension. It was hypothesized that functionally aligned RA-TKA the femoral and tibial cuts would be performed in line with the preoperative joint line orientation. Methods. Between September 2018 and January 2020, 81 RA cruciate retaining (CR) and posterior stabilized (PS) TKAs were performed at a single center. Preoperative radiographs were obtained, and measures were performed according to Paley's. Preoperatively, cuts were planned based on radiographic epiphyseal anatomies and respecting ±3° boundaries from neutral coronal alignment. Intraoperatively, the tibial and femoral cuts were modified based on the individual soft tissue-guided fine-tuning, aiming for symmetric medial and lateral gaps in flexion/extension. Robotic data were recorded. Results. A total of 56 RA-TKAs performed on varus knees were taken into account. On average, the tibial component was placed at 1.9° varus (SD 0.7) and 3.3° (SD 1.0) in the coronal and sagittal planes, respectively. The average femoral component alignment, based on the soft tissue tensioning with spoons, resulted as follows: 0.7° varus (SD 1.7) in the coronal plane and 1.8° (SD 2.1) of external rotation relative to surgical transepicondylar axis in the transverse plane. A statistically significant linear direct relationship was demonstrated between radiographic epiphyseal femoral and tibial coronal alignment and femoral (r=0.3, p<0.05) and tibial (r=0.3, p<0.01) coronal cuts, resepctively. Conclusion. Functionally aligned RA-TKA performed in varus knees, aiming for ligaments’ preservation and balanced flexion/extension gaps, provided joint line respecting femoral and tibial cuts on the coronal plane

Introduction. Robotics have been applied to total knee arthroplasty (TKA) to improve surgical precision in components’ placement, providing a physiologic ligament tensioning throughout knee range of motion. The purpose of the present study is to evaluate femoral and tibial components’ positioning in robotic-assisted TKA after fine-tuning according to soft tissue tensioning, aiming symmetric and balanced medial and lateral gaps in flexion/extension. Materials and Methods. Forty-three consecutive patients undergoing robotic-assisted TKA between November 2017 and November 2018 were included. Pre-operative radiographs were performed and measured according to Paley's. The tibial and femoral cuts were performed based on the individual intra-operative fine-tuning, checking for components’ size and placement, aiming symmetric medial and lateral gaps in flexion/extension. Cuts were adapted to radiographic epiphyseal anatomy and respecting ±2° boundaries from neutral coronal alignment. Robotic data were recorded, collecting information relative to medial and lateral gaps in flexion and extension. Results. Patients were divided based on the pre-operative coronal mechanical femoro-tibial angle (mFTA). Only knees with varus deformity (mFTA<178°), 29 cases, were taken into account. On average, the tibial component was placed at 1.2°±0.5 varus. Femoral component fine-tuning based on soft-tissues tensioning in extension and flexion determined the following alignments: 0.2°±1.2 varus on the coronal plane and 1.2°±2.2° external rotation with respect to the trans-epicondylar axis (TEA) as measured on the CT scan in the horizontal plane. The average gaps after femoral and tibial resections, resulted as follows: 19.5±0.8 mm on the medial side in extension, 20.0±0.9 mm on the lateral side in extension, 19.1±0.7 mm on the medial side in flexion and 19.5±0.7 mm on the lateral side in flexion. On average, the post-implant coronal alignment as reported by the robotic system resulted 2.0°±1.5 varus. Discussion. The proposed robotic-arm assisted TKA technique, aiming to preserve the integrity of the ligaments, provides balanced and symmetric gaps in flexion and extension and an anatomic femoral and tibial component's placement with post-implant coronal alignment within ±2° from neutral alignment

One of the more difficult tasks in surgery is to apply the optimal instrument forces and torques necessary to conduct an operation without damaging the tissue of the patient. This is especially problematic in surgical robotics, where force-feedback is totally eliminated. Thus, force sensing instruments emerge as a critical need for improving safety and surgical outcome. We propose a new measurement system that can be used in real fracture surgeries to generate quantitative knowledge of forces/torques applied by surgeon on tissues. We instrumented a periosteal elevator with a 6-DOF load-cell in order to measure forces/torques applied by the surgeons on live tissues during fracture surgeries. Acquisition software was developed in LabView to acquire force/torque data together with synchronised visual information (USB camera) of the tip interacting with the tissue, and surgeon voice recording (microphone) describing the actual procedure. Measurement system and surgical protocol were designed according to patient safety and sterilisation standards. The developed technology was tested in a pilot study during real orthopaedic surgery (consisting of removing a metal plate from the femur shaft of a patient) resulting reliable and usable. As demonstrated by subsequent data analysis, coupling force/torque data with video and audio information produced quantitative knowledge of forces/torques applied by the surgeon during the surgery. The outlined approach will be used to perform intensive force measurements during orthopaedic surgeries. The generated quantitative knowledge will be used to design a force controller and optimised actuators for a robot-assisted fracture surgery system under development at the Bristol Robotics Laboratory

Aims

Computer-assisted 3D preoperative planning software has the potential to improve postoperative stability in total hip arthroplasty (THA). Commonly, preoperative protocols simulate two functional positions (standing and relaxed sitting) but do not consider other common positions that may increase postoperative impingement and possible dislocation. This study investigates the feasibility of simulating commonly encountered positions, and positions with an increased risk of impingement, to lower postoperative impingement risk in a CT-based 3D model.