The February 2023 Spine Roundup. 360. looks at: S2AI screws: At what cost?; Just how good is spinal deformity surgery?; Is 80 years of age too late in the day for spine surgery?; Factors affecting the accuracy of pedicle screw placement in
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.
To close the surgeon in the control loop is able to take advantages of the fertile sensing information and intelligence from human being so that the complex and unpredictable surgical procedure can be better handled properly. However, there is also weakness to be strengthened. For example, the motion control of the human being is not as accurate as required. Assisted equipment for such purpose may be helpful to the procedure. Exerting large forces during the cutting process may exhaust the operator and cause fatigue. The operator may need power assistance during the surgery procedure. The response speed of human being's may not be adequate to take immediate action in certain critical situations. The constraints from the limbs and human's attention usually cause a significant delay to react the critical situations. This may lead to serious damage by failing to response immediately. For example, in knee replacement procedure, the shape of the knee joint has to be prepared by performing bone resection procedure. The surgeon cuts the bone at certain position and orientation with the help of the cutting jig from the surgical planning. The cutter cut the bone by inserting vibration saw through the slot of the cutting block. The surgeon has to stop the cutter right after the bone has been cut through by the saw so that no surrounding soft tissue, blood vessel, and even important nerves, be damaged. Currently the tactile sensing from the hand is heavily relied on by the surgeon. He has also to be experienced and dexterous. If he fails to draw back the cutter after the bone being cut through, damages to the patient may occur. Therefore there is need to develop a cutting tool, which is intelligent, knows where it is, and is able to judge what the cutting situation is, and further assists the operator to stop the cutter in case that the operator fails to do so, or too slow to response. The benefit to the patient as well as the surgeon will be significant. Therefore the purpose of the paper is to develop an algorithm to implement such functionality of auto-detection of bone cutting through for a bone cutting tool when the cutter has cut through the bone. By the developed method, the intelligent cutter can effectively detect the cutting through condition and then adopt an immediate reaction to prevent the cutter from going further and to avoid unexpected damage. An auto-detection scheme has also been developed for assisting the operator in judging whether the cutter has reached the boundary or not. The auto-detection scheme is based on analyzing the cutting force pattern in conjunction with a bilateral force controller for the hand's on robot. The bilateral force controller consists of two force controllers. The force controller on the master calculates the feedrate of the cutter according to the push force by the operator. Meanwhile, the operator can also feel the cutting force by the force controller on the slave site, which revises the feedrate of the cutter by the measured cutting force. The operator can kinesthetically feel the cutting force from the variation of the feedrate. When the cutter breaks through the boundary of the bone, the cutting force will drop suddenly to almost zero. When this special force pattern occurs, an acknowledge signal of bone been broken through will be activated. The subsequent action will be followed to stop the cutter going further. We implement this concept by defining a “cutting admittance” indicating the resistance encountered by the cutting during bone resection at different cutting feedrate. During the bone resection, the cutting admittance varies from cutting through hard or soft portions of bone. As reaching the cutting boundary, the cutting admittance will suddenly increase. A threshold value will experimentally be determined to indicate cutting through condition. Together with pushing force by the human operator, the criterion for cutting-through detection is defined. Once cutting through is detected, the admittance for cutter movement will be set zero. The cutter stops going further and the operator feel like hitting a virtual wall in front. In this paper we proposed a human robot cooperative operation method by which the robotic system can intelligently detect where the cutter has cut through the bone. Characterisation of bone cutting procedure was performed. This auto detection scheme was developed by analyzing the information of the motion and cutting force information during the bone cutting process, no medical images are required. The auto-detection bone cut through was able to transfer the experiences of human being to quantitative modeling. The developed model has been tested for its applicability and robustness by saw bones and pig's knee joints. Results have shown the virtual wall generated by the real-time bone detection scheme and active constraint control is very accurate and capable of providing a safety enhance module for computer assisted orthopaedic surgery, in particular, in total knee replacement. By this method the robot system can accomplish a safe and accurate bone cutting with a complement of an imageless navigation system and results in a low cost, but safe and effective surgical robot system.
To introduce a new robot-assisted surgical system for spinal posterior fixation which called TiRobot, based on intraoperative three-dimensional images. TiRobot has three components: the planning and navigation system, optical tracking system and robotic arm system. By combining navigation and robot techniques, TiRobot can guide the screw trajectories for orthopedic surgeries. In this randomised controlled study approved by the Ethics Committee, 40 patients were involved and all has been fully informed and sign the informed consent. 17 patients were treated by free-hand fluoroscopy-guided surgery, and 23 patients were treated by
Continuous technical improvement in spinal surgical procedures, with the aim of enhancing patient outcomes, can be assisted by the deployment of advanced technologies including navigation, intraoperative CT imaging, and surgical robots. The latest generation of robotic surgical systems allows the simultaneous application of a range of digital features that provide the surgeon with an improved view of the surgical field, often through a narrow portal. There is emerging evidence that procedure-related complications and intraoperative blood loss can be reduced if the new technologies are used by appropriately trained surgeons. Acceptance of the role of surgical robots has increased in recent years among a number of surgical specialities including general surgery, neurosurgery, and orthopaedic surgeons performing major joint arthroplasty. However, ethical challenges have emerged with the rollout of these innovations, such as ensuring surgeon competence in the use of surgical robotics and avoiding financial conflicts of interest. Therefore, it is essential that trainees aspiring to become spinal surgeons as well as established spinal specialists should develop the necessary skills to use robotic technology safely and effectively and understand the ethical framework within which the technology is introduced. Traditional and more recently developed platforms exist to aid skill acquisition and surgical training which are described. The aim of this narrative review is to describe the role of surgical robotics in spinal surgery, describe measures of proficiency, and present the range of training platforms that institutions can use to ensure they employ confident spine surgeons adequately prepared for the era of robotic spinal surgery. Cite this article:
Treating fractures is expensive and includes a long post-operative care. Intra-articular fractures are often treated with open surgery that require massive soft tissue incisions, long healing time and are often accompanied by deep wound infections. Minimally invasive surgery (MIS) is an alternative to this but when performed by surgeons and supported by X-rays does not achieve the required accuracy of surgical treatment. Functional and non-functional requirements of the system were established by conducting interviews with orthopaedic surgeons and attending fracture surgeries at Bristol Royal Infirmary to gain first-hand experience of the complexities involved. A robot-assisted fracture system (RAFS) has been designed and built for a distal femur fracture but can generally serve as a platform for other fracture types.Background
Methods
While image guidance and neuro-navigation have enabled a more accurate positioning of pedicle implants, robot-assisted placement of pedicle screws appears to overcome the disadvantages of the two first systems. However, recent data concerning the superiority of robots currently available to assist spinal surgeons in the accurate positioning of implants are conflicting. The aim of our study was to evaluate the percentage of accurate positioning of pedicle screws inserted using a new robotic-guidance system. Patients were operated on successively by the same surgeon using robotic-assistance (RA; n=40) or by the freehand conventional technique (FH; n=54). Ten and eleven patients from the robot (RG) and freehand (FHG) groups respectively, age-matched and all suffering from degenerative lumbar spine disease were compared. Patient characteristics as well as the duration of the operation and of exposure to X-rays were recorded. The Gertzbein Robbins classification was used to evaluate implant placement. Data wer compared between the groups. Pedicle screw placement in RG patients was achieved using the ROSA™ (Medtech) robot comprising a compact robotic arm on a floor-fixable mobile base. By permanently monitoring the patient's movements, this image-guided tool helps more accurately to pinpoint the pedicle entry point and to control the trajectory. The mean age of patients in each group (RG and FHG) was 63 years. Mean BMI and operating time among the RG and FHG were respectively 26 and 27 kg/m2, and 187 and 119 min. Accurate placement of the implant (score A-B) was achieved in 97.2% of patients in the RG (n=36) and in 92.6% of those in the FHG (n=54). Four implants in the RG were placed manually following failed robotic assistance. The mean duration of X-ray exposure per patient was 1 min 42s in the RG and 41s in the FHG. We report a higher rate of accuracy with robotic assistance as compared to the FH technique. Exposure time was greater in the RG partly due to the fluoroscopic control of the implants required for this pilot study of feasibility. Limitations of the study include its small sized and non-randomised sample. Nevertheless, these preliminary results are encouraging for the development of new robotic techniques for spinal surgery.
A functional total knee replacement has to be well aligned, which implies that it should lie along the mechanical axis and in the correct axial and rotational planes. Incorrect alignment will lead to abnormal wear, early mechanical loosening, and patellofemoral problems. There has been increased interest of late in total knee arthroplasty with robot assistance. This study was conducted to determine if robot-assisted total knee arthroplasty is superior to the conventional surgical method with regard to the precision of implant positioning. Twenty knee replacements of ten robot-assisted and another ten conventional operations were performed on ten cadavers. Two experienced surgeons performed the surgery. Both procedures were undertaken by one surgeon on each cadaver. The choice of which was to be done first was randomized. After the implantation of the prosthesis, the mechanical-axis deviation, femoral coronal angle, tibial coronal angle, femoral sagittal angle, tibial sagittal angle, and femoral rotational alignment were measured via three-dimensional CT scanning. These variants were then compared with the preoperative planned values. In the
Introduction and Objective. Total knee arthroplasty (TKA) is a frequently and increasingly performed surgery in the treatment of disabling knee osteoarthritis. The rising number of procedures and related revisions pose an increasing economic burden on health care systems. In an attempt to lower the revision rate due to component malalignment and soft tissue imbalance in TKA, robotic assistance (RA) has been introduced in the operating theatre. The primary objective of this study is to provide the results of a theoretical, preliminary cost-effectiveness analysis of RA TKA. Materials and Methods. A Markov state-transition model was designed to model the health status of sixty-seven-year-old patients in need of TKA due to primary osteoarthritis over a twenty-year period following their knee joint replacement. Transitional probabilities and independent variables were extracted from existing literature. Patients’ state in the transition model was able to change on an annual basis. The main differences between the conventional and RA TKA were the outlier rate in the coronal plane and the cost of the procedure. In RA TKA, it was hypothesized that there were lower revision rates due to a lower outlier rate compared to conventional TKA. Results. The value attributed to the utility both for primary and revision surgery has the biggest impact on the ICER, followed by the rate of successful primary surgery and the cost of RA-technology. Only 2.18–2.34% of the samples yielded from the probabilistic sensitivity analysis proved to be cost-effective (threshold set at $50000/QALY). A calculated surgical volume of at least 191–253 cases per robot per year is needed to prove cost-effective taking the predetermined parameter values into account. Conclusions. Robot-assisted TKA might be a cost-effective procedure compared to conventional TKA if a minimum of 191 cases are performed on a yearly basis, depending on the cost of the robot. The cost-benefit of the robotic TKA surgery is mainly based on a decreased revision rate. This study is based on the assumption that alignment is a predictor of success in total knee arthroplasty. Until there is data confirming the assertion that alignment predicts success
The traditional stem in cement-less total hip replacement was designed as a straight stem. This design was chosen to compensate for lack of initial stability provided by cement. Specifically the box shape of the implant achieved rotational stability and the wedge shape promised proximal press fit. Therefore also the first
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.
Introduction. The placement of a large interbody implant allows for a larger surface area for fusion, vis a vis, via retroperitoneal direct anterior, antero-lateral and lateral approaches. At the same time, spinal navigation facilitates a minimally invasive fixation for inserting posterior pedicle screws. We report on the first procedures in the United Kingdom performed by a single-surgeon at a single- centre using navigated
Introduction. Mechanically aligned total knee arthroplasty(TKA) relies on restoring the hip-knee-ankle angle of the limb to neutral or as close to a straight line as possible. This principle is based on studies that suggest limb and knee alignment is related long term survival and wear. For that cause, there has been recent attention concerning computer-assisted TKA and robot is also one of the most helpful instruments for restoring neutral alignment as known. But many reported data have shown that 20% to 25% of patients with mechanically aligned TKA are dissatisfied. Accordingly, kinematically aligned TKA was implemented as an alternative alignment strategy with the goal of reducing prevalence of unexplained pain, stiffness, and instability and improving the rate of recovery, kinematics, and contact forces. So, we want to report our extremely early experience of robot-assisted TKA planned by kinematic method. Materials and Methods. This study evaluated the very short term results (6 weeks follow up) after robot-assisted TKA aligned kinematically. 50 knees in 36 patients, who could be followed up more than 6 weeks after surgery from December 2014 to January 2015, were evaluated prospectively. The diagnosis was primary osteoarthritis in all cases. The operation was performed with ROBODOC (ISS Inc., CA, USA) along with the ORTHODOC (ISS Inc., CA, USA) planning computer. The cutting plan was made by single radius femoral component concept, each femoral condyles shape-matched method along the transverse axis using multi-channel CT and MRI to place the implant along the patient's premorbid joint line. Radiographic measurements were made from long bone scanograms. Clinical outcomes and motion were measured preoperatively and 6 weeks postoperatively. Results. The range of motion increased from preoperative mean 113.4 (±5.4, 85 to 130) to postoperative mean 127.3 (±7.4, 90 to 140) at last follow up. The mean knee score and functional score improved from 35.4 (±10.3, 10 to 55) and 30.1 (±7.7, 10 to 60) before surgery to 88.6 (±5.8, 60 to 100) and 90.7 (±9.6, 60 to 100) at last follow up. The WOMAC score was improved from 52(±15.5) to 20(±14.8) at last follow up. The postoperative Hip-knee-ankle alignment was −1.3±2.8. The femoral component was 2.1 valgus and tibial component was 2.8 varus along the mechanical axis in coronal plane. There were no complications and failures. Conclusion. On the basis of our results, we are cautiously optimistic about robot-assisted TKA by kinematically alignment. More anatomic alignment of the implant can be associated with better flexion and better clinical outcomes scores in the kinematically aligned method in our thinking. But, at this starting point, more comparative studies with mechanical aligned group are needed and we must explore about implant survivalship issues and implant loading issues in dynamic and static condition that someone is worrying about. If the problem can be solved, there is no use worrying about it in our thinking. And what is more, the
INTRODUCTION. Allograft reconstruction after resection of primary bone sarcomas has a non-union rate of approximately 20%. Achieving a wide surface area of contact between host and allograft bone is one of the most important factors to help reduce the non-union rate. We developed a novel technique of haptic
INTRODUCTION. Unicompartmental knee arthroplasty (UKA) allows replacement of a single compartment in patients who have isolated osteoarthritis as a minimally invasive procedure. However, limited visualization of the surgical site provides challenges in ensuring accurate alignment and placement of the prosthesis. With
The Coronal Plane Alignment of the Knee (CPAK) classification has been developed to predict individual variations in inherent knee alignment. The impact of preoperative and postoperative CPAK classification phenotype on the postoperative clinical outcomes of total knee arthroplasty (TKA) remains elusive. This study aimed to examine the effect of postoperative CPAK classification phenotypes (I to IX), and their pre- to postoperative changes on patient-reported outcome measures (PROMs). A questionnaire was administered to 340 patients (422 knees) who underwent primary TKA for osteoarthritis (OA) between September 2013 and June 2019. A total of 231 patients (284 knees) responded. The Knee Society Score 2011 (KSS 2011), Knee injury and Osteoarthritis Outcome Score-12 (KOOS-12), and Forgotten Joint Score-12 (FJS-12) were used to assess clinical outcomes. Using preoperative and postoperative anteroposterior full-leg radiographs, the arithmetic hip-knee-ankle angle (aHKA) and joint line obliquity (JLO) were calculated and classified based on the CPAK classification. To investigate the impact on PROMs, multivariable regression analyses using stepwise selection were conducted, considering factors such as age at surgery, time since surgery, BMI, sex, implant use, postoperative aHKA classification, JLO classification, and changes in aHKA and JLO classifications from preoperative to postoperative.Aims
Methods
Unicompartmental knee arthroplasty (UKA) is an increasingly attractive and clinically successful treatment for individuals with isolated medial compartment disease who demand high levels of function. A major challenge with UKA is to place the components accurately so they are mechanically harmonious with the retained joint surfaces, ligaments and capsule. Misalignment of UKA components compromises clinical outcomes and implant longevity. Cobb et al. (JBJS-Br 2006) showed that robot-assisted placement of UKA components was more accurate than traditional techniques, and subsequently that the clinical outcomes were improved. Cobb’s method, however, employed rigid intraoperative stabilization of the bones in a stereotactic frame, which is impractical for routine clinical use. Robotic systems have now advanced to include dynamic bone tracking technologies so that rigid fixation is no longer required. The question is -Do these robotic systems with dynamic bone tracking provide the same accuracy advantages demonstrated with robotic systems with rigidly fixed bones? We compared robot-assisted and traditionally instrumented UKA in six bilateral pairs of cadaver specimens. In all knees, a CT-based preoperative plan was performed to determine the ideal positions and orientations for the implant components. Traditional manual instruments were utilized with a tissue-sparing approach to implant one knee of each pair. A haptic robotic system acting as a virtual cutting guide was used to perform the robot-assisted UKA, again with a tissue-sparing approach. Postoperative CT scans were obtained from all knees, and the 3D placement errors were quantified using 3D-to-3D registration of implant and bone models to the reconstructed CT volumes. The magnitudes of femoral implant orientation error were significantly smaller for the robot-assisted implants compared to traditionally implanted components (4° vs 11°, p<
0.001), but the magnitudes of femoral placement error did not reach significance (3mm vs. 5mm, p=0.056). The magnitudes of tibial implant placement error were not significantly different (4mm vs. 5mm and 7° vs. 7°, p>
0.05). Well-placed UKA implants can provide durable and excellent functional results, which is an increasingly attractive option for young and active patients with severe compartmental osteoarthritis who wish not to have or to delay a total knee replacement. Previous studies have demonstrated significant improvement in implant placement accuracy and clinical results with
Robots have been used in surgery since the late
1980s. Orthopaedic surgery began to incorporate robotic technology
in 1992, with the introduction of ROBODOC, for the planning and
performance of total hip replacement. The use of robotic systems
has subsequently increased, with promising short-term radiological
outcomes when compared with traditional orthopaedic procedures.
Robotic systems can be classified into two categories: autonomous
and haptic (or surgeon-guided). Passive surgery systems, which represent
a third type of technology, have also been adopted recently by orthopaedic
surgeons. While autonomous systems have fallen out of favour, tactile systems
with technological improvements have become widely used. Specifically,
the use of tactile and passive robotic systems in unicompartmental
knee replacement (UKR) has addressed some of the historical mechanisms
of failure of non-robotic UKR. These systems assist with increasing
the accuracy of the alignment of the components and produce more
consistent ligament balance. Short-term improvements in clinical
and radiological outcomes have increased the popularity of robot-assisted
UKR.
The aim of this study was to determine the risk of tibial eminence avulsion intraoperatively for bi-unicondylar knee arthroplasty (Bi-UKA), with consideration of the effect of implant positioning, overstuffing, and sex, compared to the risk for isolated medial unicondylar knee arthroplasty (UKA-M) and bicruciate-retaining total knee arthroplasty (BCR-TKA). Two experimentally validated finite element models of tibia were implanted with UKA-M, Bi-UKA, and BCR-TKA. Intraoperative loads were applied through the condyles, anterior cruciate ligament (ACL), medial collateral ligament (MCL), and lateral collateral ligament (LCL), and the risk of fracture (ROF) was evaluated in the spine as the ratio of the 95th percentile maximum principal elastic strains over the tensile yield strain of proximal tibial bone.Aims
Methods
The aim of this study was to assess the accuracy of pedicle screw placement, as well as intraoperative factors, radiation exposure, and complication rates in adult patients with degenerative disorders of the thoracic and lumbar spines who have undergone robotic-navigated spinal surgery using a contemporary system. The authors reviewed the prospectively collected data on 196 adult patients who had pedicle screws implanted with robot-navigated assistance (RNA) using the Mazor X Stealth system between June 2019 and March 2022. Pedicle screws were implanted by one experienced spinal surgeon after completion of a learning period. The accuracy of pedicle screw placement was determined using intraoperative 3D fluoroscopy.Aims
Methods