Robotic-assisted Knee Arthroplasty Research Articles

Adverse events related to robotic-assisted knee arthroplasty: a cross-sectional study from the MAUDE database.

Robotic-assisted surgical technique has been clinically available for decades, yet real-world adverse events (AEs) and complications associated with primary knee arthroplasty remain unclear. In March 2023, we searched the FDA website and extracted AEs related to robotic assisted knee arthroplasty (RAKA) from the MAUDE database over the past 10 years. The "Brand Name" function queried major robotic platforms, including active and semi-active systems. The overall incidence of AEs was estimated based on annual surgical volume from the current American Joint Replacement Registry (AJRR). Two authors independently collected data on event date, event type, device problem, and patient problem. Of 839 eligible reports, device malfunction comprised mechanical failure (343/839, 40.88%) and software failure (261/839, 31.11%). For surgical complications, inappropriate bone resection (115/839, 13.71%) was most frequent, followed by bone/soft tissue damage (83/839, 9.89%). Notably, over-resection exceeding 2mm (88/839, 10.49%), joint infection (25/839, 2.98%), and aseptic loosening (1/839, 0.12%) were major complications. Only two track pins related AEs were found. Moreover, the distribution of these AEs differed substantially between robot manufacturers. According to the AEs volume and AJRR data, the overall incidences of AEs related to RAKAs were calculated with 0.83% (839/100,892) between November 2010 and March 2023. Our analysis shows that while reported AEs might be increasing for RAKAs, the overall rate remains relatively low. Reassuringly, device malfunction was the most commonly AEs observed, with a minor impact on postoperative outcomes. Furthermore, our data provide a benchmark for patients, surgeons, and manufacturers to evaluate RAKA performance, though continued improvement in reducing serious AEs incidence is warranted.

Real-world accuracy of robotic-assisted total knee arthroplasty and its impact on expedited recovery.

Despite total knee arthroplasty (TKA) being the gold standard for end-stage knee osteoarthritis, 20% of patients remain dissatisfied. Robotic-assisted arthroplasty promises unparalleled control of the accuracy of bone cuts, implant positioning, control of gap balance, and resultant hip-knee-ankle (HKA) axis. Patients underwent clinical and radiological assessments, including knee CT scans and patient-reported outcome measures (PROMs), preoperatively. Follow-up assessments were conducted at 2weeks, 6weeks, and 3months post-operatively, with imaging repeated at 6weeks. A total of 155 patients underwent robotic-assisted TKA and have completed 3months of follow-up. Mean pre-operative HKA axis was 7.39 ± 5.52 degrees varus, improving to 1.34 ± 2.22 degrees varus post-operatively. Restoration of HKA axis was 0.76 ± 1.9 degrees from intra-operative planning (p < 0.0005). Implant placement accuracy in the coronal plane was 0.08 ± 1.36 degrees (p = 0.458) for the femoral component and 0.71 ± 1.3 degrees (p < 0.0005) for the tibial component. Rotational alignment mean deviation was 0.39 ± 1.49 degrees (p = 0.001). Most patients (98.1%) had ≤ 2mm difference in extension-flexion gaps. PROM scores showed improvement and exceeded pre-operative scores by 6weeks post-surgery. Robotic-assisted knee arthroplasty provides precise control over traditionally subjective factors, demonstrating excellent early post-operative outcomes.Level of evidence Prospective observational study-II.

Evaluating the cost of robotic-assisted total and unicompartmental knee arthroplasty.

As uptake of robotic-assisted arthroplasty increases there is a need for economic evaluation of the implementation and ongoing costs associated with robotic surgery. The aims of this study were to describe the in-hospital cost of robotic-assisted total knee arthroplasty (RA-TKA) and robotic-assisted unicompartmental knee arthroplasty (RA-UKA) and determine the influence of patient characteristics and surgical outcomes on cost. This prospective cohort study included adult patients (≥ 18years) undergoing primary unilateral RA-TKA and RA-UKA, at a tertiary hospital in Sydney between April 2017 and June 2021. Patient characteristics, surgical outcomes, and in-hospital cost variables were extracted from hospital medical records. Differences between outcomes for RA-TKA and RA-UKA were compared using independent sample t-tests. Logistic regression was performed to determine drivers of cost. Of the 308 robotic-assisted procedures, 247 were RA-TKA and 61 were RA-UKA. Surgical time, time in the operating room, and length of stay were significantly shorter in RA-UKA (p < 0.001); whereas RA-TKA patients were older (p = 0.002) and more likely to be discharged to in-patient rehabilitation (p = 0.009). Total in-hospital cost was significantly higher for RA-TKA cases (AU$18580.02 vs $13275.38; p < 0.001). Robotic system and maintenance cost per case was AU$3867.00 for TKA and AU$5008.77 for UKA. Patients born overseas and lower volume robotic surgeons were significantly associated with higher total cost of RA-UKA. Increasing age and male gender were significantly associated with higher total cost of RA-TKA. Total cost was significantly higher for RA-TKA than RA-UKA. Robotic system costs for RA-UKA are inflated by the software cost relative to the volume of cases compared with RA-TKA. Cost is an important consideration when evaluating long term benefits of robotic-assisted knee arthroplasty in future studies to provide evidence for the economic sustainability of this practice.

Robot-assisted knee arthroplasty: Analyzing the learning curve and initial institutional experience

Robot-assisted total knee arthroplasty (rTKA) involves a learning curve for orthopedic surgeons. The aim of the present study was to assess the surgical times of rTKA procedures performed by initial stage and proficiency stage surgeons in comparison with times of conventional total knee arthroplasty (cTKA). The results reveal that the learning curve for rTKA varies considerable between surgeons, suggesting that the skill and aptitude of the individual to adapt to the robotic system play key roles in the learning process. Proficiency stage surgeons were able to reduce rTKA surgical times to levels comparable with those of conventional surgeries after performing approximately 30 to 40 robotic procedures. Ongoing research has shown promising outcomes in terms of improved clinical results and reduced complications following the application of advanced robotic technology to total knee arthroplasty.

Robotic-Assisted Knee Arthroplasty: Insights and Implications From Current Literature.

Robotic-assisted knee arthroplasty has emerged as a promising development, aiming to enhance surgical precision and patient outcomes. This literature review examines the clinical efficacy, cost implications, environmental impact, and potential of telesurgery in robotic-assisted total knee arthroplasty (RATKA) and robotic-assisted unicompartmental knee arthroplasty (RAUKA) relative to conventional techniques. A thorough literature search was conducted across medical databases. Clinical and radiological outcomes of RATKA and RAUKA were extracted and analyzed. Direct costs, operating time, surgeon learning curve, environmental implications, and the futuristic concept of telesurgery were also considered. Subjective patient assessments such as WOMAC, Oxford Knee Score, and SF-36, alongside objective measures like HSS score and KSS, were commonly used. Radiological parameters like hip-knee-ankle (HKA) and femorotibial angle provided insights into post-operative alignment. Evidence indicated sporadic high-level design studies, often with limited samples. Cost remains a major constraint with robotic systems, though high-volume cases might offset expenses. Environmental assessments revealed robotic surgeries generate a higher carbon footprint. Telesurgery, an evolving field, could transcend geographical boundaries but is not without challenges, including high costs, latency issues, and cyber threats. While robotic-assisted surgeries may hold promise in the future, substantial barriers, including acquisition costs, potential surgeon deskilling, and environmental concerns, need addressing. Greater robot utilization may drive costs down with more competitors entering the market. Continued research, especially multi-center RCTs, is pivotal to solidifying the role of robotic systems in knee arthroplasty.

Mapping knowledge landscapes and emerging trends of robotic-assisted knee arthroplasty: A bibliometric analysis.

The robotic-assisted knee arthroplasty has gained increasing attention in the research field. To date, no comprehensive bibliometric analysis has been carried out on this topic. The present study aimed to introduce the research status and hotspots and explore the field of robotic-assisted knee arthroplasty from a bibliometric perspective. The Web of Science Core Collection database was utilized to retrieve articles and reviews on robotic-assisted knee arthroplasty published between 1993 and 2023. CiteSpace, VOSviewer, Scimago Graphica, Pajek, and a bibliometric online analysis platform (http://bibliometric.com/) were employed to analyze the regions, institutions, journals, authors, and keywords, aiming to predict the latest trends in research related to robotic-assisted knee arthroplasty. This study encompasses 697 records. The annual publication count pertaining to robotic-assisted knee arthroplasty demonstrates consistent growth. The United States leads with the highest number of studies (298), trailed by the United Kingdom (110) and France (49). The Hospital for Special Surgery emerges as the most prolific institution, while Professor Mont, Michael A holds significant author influence. The Journal of Arthroplasty reigns supreme in this field, boasting the highest publication and citation figures. Funding sources predominantly include Stryker (34), Smith Nephew (19), and the National Natural Science Foundation of China (17). Noteworthy research themes within robotic-assisted knee arthroplasty encompass patient satisfaction, kinematic alignment, and clinical benefits. The landscape of robotic-assisted knee arthroplasty research is thriving. Anticipated trajectories of research will be geared toward refining the precision of robotic technology and enhancing clinical outcomes within the realm of robotic-assisted knee arthroplasty.

Evaluation of radiologic predisposing factors for greater trochanteric pain syndrome

Objectives: Greater trochanteric pain syndrome (GTPS) is one of the causes of lateral hip pain. We aimed to determine the significance of certain anatomical parameters related to GTPS in imaging tests. Methods: Data of patients who were treated with glucocorticoid injection for trochanteric bursitis in our clinic between July 2019 and July 2022 for GTPS were analyzed. The control group was constituted of patients without GTPS but with hip and spinal problems who had pelvic computerized tomography (CT) images and undergone robotic-assisted knee arthroplasty. Standard anteroposterior pelvic radiograms, pelvic CTs, or magnetic resonance images were evaluated for anatomical parameters. Results: Among anatomical parameters, acetabular anteversion, length of trochanter major, and abductor index were significantly different between the patients with and without GTPS. Although mean age was different between the GTPS and control patient groups, age was not found to be correlated with any anatomical parameter. Abductor lever arm length (p = 0.001) and abductor index (p = 0.009) were found to be correlated. Conclusions: The length of trochanter major and abductor index were shown to be predisposing anatomical parameters for GTPS.

Retrospective analysis of robotic unicompartmental and total knee arthroplasties: patient demographics and outcomes.

With the growing number of robotic knee arthroplasties being performed, new outcomes must be analyzed to provide a database for comparing robotic and nonrobotic surgeries. These results can be utilized in the future to properly assess the significance of utilizing robotic technology in the operating room regarding patient outcomes and cost. The aims of this study are to: (1) analyze adverse outcomes from robotic-assisted knee arthroplasty and its relation to sex, body mass index (BMI), and age; and (2) explore any possible differences in outcomes among robotic-assisted unicompartmental knee arthroplasty (UKA) and robotic-assisted total knee arthroplasty (TKA). It is hypothesized that sex, BMI, and age will play a role in adverse events experienced among robotic-assisted knee arthroplasty. It is hypothesized that adverse outcomes will differ in robotic-assisted TKA v UKA. A retrospective analysis was performed utilizing 1,300 patient cases from a single surgeon that underwent robotic-assisted UKA or TKA utilizing a robotic surgical system. Demographics were sorted by age, sex, and BMI. Outcomes were sorted by the type of adverse event. The most common adverse event was further statistically analyzed by age, sex, and BMI and then compared to the total cohort. The most common adverse event was also broken down by TKA vs. UKA. The average age of the individuals undergoing this procedure was 63.6 years, with 52.3 % being female. The average BMI was 32.2. Of the 87 patients who experienced adverse events, 111 total events were documented. Manipulation under anesthesia (MUA) was the highest experienced adverse event. Among the MUA events, 79.5 % had a BMI over 30 (p=0.067), 72.8 % were female (p=0.014), and the average age was 59 years (p=0.019). Among the MUA adverse events, 76.9 % (n=30) were following a TKA and 23.1 % were following a UKA. When considering the entire sample (n=1,300), there was a statistically significant 12.6 times greater odds that an MUA occurred among those who had a TKA vs. UKA (p<0.001). Similar results were discovered when only considering those who had experienced an adverse event (n=87) because the odds of an MUA occurring among those who underwent a TKA was 4.67 times greater than those who underwent a UKA (p<0.001). MUA was the most common adverse event in this cohort of robotic-assisted knee arthroplasties. The other adverse events did not yield large enough cohort sizes to analyze statistically in relation to specific patient demographics. Younger patients and females were at significantly greater odds of needing MUA. A BMI over 30 was not found to have a statistically significant risk of needing an MUA after robotic-assisted knee arthroplasty. Among the total cohort, those who underwent a TKA were at a 12.6 times greater odds of needing an MUA than those who received a UKA.

Reverse coronal deformity: use of robotic total knee arthroplasty for identification and correction.

Despite continued advances in techniques and implant designs, a population of patients who are dissatisfied after total knee arthroplasty (TKA) remains. During robotic-assisted arthroplasty, real-time intraoperative assessment of patient knee alignment is performed. Here, we assess the prevalence of an under-appreciated deformity, reverse coronal deformity (RCD), and the benefits of utilizing robotic-assisted knee arthroplasty to help correct this dynamic deformity. A retrospective study evaluating patients undergoing robotic-assisted cruciate-retaining TKA was performed. Intraoperative measurements were obtained using tibial and femoral arrays to assess coronal plane deformity at full extension and at 90° flexion. RCD was defined as ≥ 2° varus in knee extension that reversed to ≥ 2° valgus in flexion, or vice-versa. Coronal plane deformity was then reassessed after robotic-assisted bony resection and implant placement. Of 204 patients that underwent TKA, 16 patients (7.8%) were found to have RCD, with 14 patients (87.5%) transitioning from varus in extension to valgus in flexion. The average coronal deformity was 7.75°, with a maximum of 12°. These improved to an average coronal change of 0.93° post-TKA. Final medial and lateral gaps were all balanced to within 1° in extension and flexion. Another 34 patients (16.7%) had ≥ 5° change in coronal plane deformity from extension to flexion (average 6.39°), however, did not experience a reversal of their coronal deformity. Outcomes were assessed with KOOS Jr. scores postoperatively. Computer and robotic assistance were utilized to demonstrate the prevalence of RCD. We also demonstrated accurate identification and successfully balancing of RCD utilizing robotic-assisted TKA. An increased awareness of these dynamic deformities could aid surgeons in proper gap balancing even in the absence of navigation and robotic-assisted surgery.

ASSESSING PREOPERATIVE LOWER LIMB CORONAL ALIGNMENT IN THE SETTING OF KNEE ARTHROPLASTY: A COMPARISON OF WEIGHTBEARING HIP-KNEE-ANKLE RADIOGRAPHS WITH INTRAOPERATIVE ASSESSMENT USING CT-BASED NAVIGATION

Accurate evaluation of lower limb coronal alignment is essential for effective pre-operative planning of knee arthroplasty. Weightbearing hip-knee-ankle (HKA) radiographs are considered the gold standard. Mako SmartRobotics uses CT-based navigation to provide intra-operative data on lower limb coronal alignment during robotic assisted knee arthroplasty. This study aimed to compare the correlation between the two methods in assessing coronal plane alignment.Patients undergoing Mako partial (PKA) or total knee arthroplasty (TKA) were identified from our hospital database. The hospital PACS system was used to measure pre-operative coronal plane alignment on HKA radiographs. This data was correlated to the intraoperative deformity assessment during Mako PKA and TKA surgery.443 consecutive Mako knee arthroplasties were performed between November 2019 and December 2021. Weightbearing HKA radiographs were done in 56% of cases. Data for intraoperative coronal plane alignment was available for 414 patients. 378 knees were aligned in varus, and 36 in valgus. Mean varus deformity was 7.46° (SD 3.89) on HKA vs 7.13° (SD 3.56) on Mako intraoperative assessment, with a moderate correlation (R= 0.50, p&lt;0.0001). Intraoperative varus deformity of 0-4° correlated to HKA measured varus (within 3°) in 60% of cases, compared to 28% for 5-9°, 17% for 10-14°, and in no cases with &gt;15° deformity. Mean valgus deformity was 6.44° (SD 4.68) on HKA vs 4.75° (SD 3.79) for Mako, with poor correlation (R=0.18, p=0.38).In this series, the correlation between weightbearing HKA radiographs and intraoperative alignment assessment using Mako SmartRobotics appears to be poor, with greater deformities having poorer correlation.

Future implications of navigation in total knee arthroplasty

After more than two decades of experience with computer-assisted knee arthroplasty, extensive experience and study data are available, allowing aprofound evaluation. Undoubtedly, computer-assisted knee arthroplasty has been proven to achieve excellent results for implant positioning and long-leg axis reconstruction. Thus, computer-assisted knee arthroplasty represents the current gold standard to avoid unintended malpositioning of total knee components for neutrally aligned implants and individualized implant alignment (kinematic alignment, adjusted mechanical alignment, and others). Previous studies could not show significant differences in functional outcomes and patient satisfaction. However, recent meta-analyses showed relevant advantages of computer-assisted knee arthroplasty. These results could be based on further developments in software-assisted soft tissue balancing and more sensitive evaluation methods of follow-up examinations. Further, international registries show advantages of computer-assisted knee arthroplasty regarding long-term outcomes. In particular, the Australian arthroplasty registry describes asignificantly lower revision rate due to aseptic loosening/osteolysis in the computer-assisted knee arthroplasty group, analyzing aperiod of up to 17years. These positive effects can already be proven six months following surgery. However, despite demonstrated benefits, computer-assisted knee arthroplasty has not yet become established in daily routine, and wide regional variations in its use are observed. Newer developments such as robotic-assisted knee arthroplasty, primarily based on navigation techniques, are currently being heavily promoted. However, this new technology must justify its enormous additional costs and prove its advantages compared to computer-assisted knee arthroplasty. In the backdrop of the development of computer-assisted knee arthroplasty, this might be adifficult task.

The learning curve in robotic assisted knee arthroplasty is flattened by the presence of a surgeon experienced with robotic assisted surgery

PurposeThe purpose of this study was to investigate the learning curve associated with robotic assisted knee arthroplasty (RAS KA). Therefore, the evaluation of the influence of an experienced surgeon on the overall team performance of three surgeons regarding the learning curve in RAS KA was investigated. It was hypothesized that the presence of an experienced surgeon flattens the learning curve and that there was no inflection point for the learning curve of the surgical team.MethodsFifty-five cases consisting of 31 total knee arthroplasties (TKA) and 24 unicompartmental arthroplasties (UKA) performed by three surgeons during 2021 were prospectively investigated. Single surgeon and team performance for operation time learning curve and inflection points were investigated using cumulative sum analysis (CUSUM).ResultsA downward trend line for individual surgeons and the team performance regarding the operation time learning curve was observed. No inflexion point was observed for the overall team performance regarding TKA and UKA. The surgeon that performed all cases with the assistance of the experienced surgeon had significantly shorter surgical times than the surgeon that only occasionally received assistance from the experienced surgeon (p = 0.004 TKA; p = 0.002 UKA).ConclusionThe presence of an experienced surgeon in robotically assisted knee arthroplasty can flatten the learning curve of the surgical team formerly unexperienced in robotic assisted systems. Manufacturers should provide expanded support during initial cases in centres without previous experience to robotic assisted knee arthroplasty.Level of evidenceIII.

Pin-Related Complications in Computer Navigated and Robotic-Assisted Knee Arthroplasty: A Systematic Review

BackgroundComputer-assisted navigation (CAN) and robotic-assisted (RA) knee arthroplasty procedures carry unique risks of tracking pin-related complications. This systematic review aimed to quantitatively assess the incidence, timing, treatment, and clinical outcomes of all tracking pin-related complications following CAN and RA knee arthroplasty. MethodsA systematic review was performed using PubMed, Cochrane Central and Scopus databases. All clinical studies that documented pin-related complications associated with the use of CAN or RA for total or partial knee arthroplasty were included. Descriptive statistics were analyzed when data were available. ResultsThirty-six studies were included: 18 case reports (25 cases) and 18 randomized controlled trials, cohort studies and case series i.e., non-case reports (7,336 cases). The most common pin-related complication among case reports was fracture (n = 22; 81%). The overall rate of pin-related complications among non-case reports was 1.4%. The intraoperative and postoperative complication with the highest incidence were pin dislodgement (0.6%) and superficial pin site infections (0.6%), respectively. Most postoperative complications were related to the tibial site (69%). All complications were effectively treated and resolved at follow-up. ConclusionPin-related complications following CAN and RA knee arthroplasty are relatively uncommon. While pin loosening, superficial infections and fractures have been most commonly documented, other complications such as vascular injury, myositis ossificans, and osteomyelitis can also occur. The potential for pin-related complications should be considered by arthroplasty surgeons, especially during early stages of adoption. Further studies investigating patient risk factors for pin-related complications are warranted.

Robotic-Assisted Surgical Systems for Knee Arthroplasty

&#x0D; Overall, there was no consensus in the evidence to indicate that robotic-assisted knee arthroplasty provided any superior clinical effectiveness outcomes when compared to conventional techniques.&#x0D; No evidence indicated that robot-assisted knee arthroplasty had worse clinical outcomes than conventional techniques. Evidence did support the association of robotic-assisted knee arthroplasty with decreased length of hospital stay and increased operative time.&#x0D; Further adequately powered studies of short-term and long-term clinical effectiveness for robotic-assisted knee arthroplasty are required to definitively demonstrate any potential benefits for patients requiring knee arthroplasty.&#x0D; Robotic-assisted knee arthroplasty was consistently modelled as cost-effective when clinical inputs included improved quality of life and reduced rates of surgical revisions when compared with conventional techniques. The clinical effectiveness evidence reviewed in this report was unable to adequately support these clinical inputs as accurate.&#x0D;

Robot-assisted Knee Arthroplasty: Randomized Clinical Trial

BACKGROUND: Osteoarthritis of the knee joint leads to a decrease in the volume of movements, a violation of the sliding of articular surfaces, and a change in the axis of the limb under load, which affects the biomechanics of walking. AIM: This study aims to compare the results of robot-assisted total knee arthroplasty (TKA) and manual techniques, their influence on the biomechanical and podometric parameters of the patient’s walk. METHODS: A prospective randomized study of 68 patients was carried out in the period from 2020 to 2021. Our follow-up period was 1 year. All patients were performed arthroplasty of one knee joint. The main Group “A” included 33 patients TKA with the use of an active robotic setting “TSolution-One” (“THINK Surgical, Inc.” [Fremont, California, USA]); the comparison Group “B” consisted of 35 patients with manual technic of TKA. We studied pain syndrome on the visual analog scale, functional state on the Oxford Knee Score (OKS) and Western Ontario and McMaster Universities Arthritis Index (WOMAC), the volume of ROM movements, and the deviation of the mechanical axis by teleroentgenography of the lower limb. Objective analysis of limb function was performed on the «Alter-G» and the «C-mill». RESULTS: Post-operative pain syndrome on the 1st day after surgery in Group A is stronger by 7.9%, but by the 5th day after surgery in Group A, the pain syndrome is lower by 14.3%. ROM in Group A is better by 16% by 3 months after surgery, after 1 year by 10%. The positioning accuracy of the implant in Group A is 30% better. There are no statistically significant differences in the OKS and WOMAC scales between the groups. The results of restoring normal step in Group A are 13.5% better than in Group B. CONCLUSIONS: Robot-assisted TKA gives more accurate alignment of the mechanical axis, which improves the biomechanics of walking.

Editor's Spotlight/Take 5: How Large a Study Is Needed to Detect TKA Revision Rate Reductions Attributable to Robotic or Navigated Technologies? A Simulation-based Power Analysis.

Editor's Spotlight/Take 5: How Large a Study Is Needed to Detect TKA Revision Rate Reductions Attributable to Robotic or Navigated Technologies? A Simulation-based Power Analysis.

Robotic-assisted knee arthroplasty: an evolution in progress. A concise review of the available systems and the data supporting them.

A review of the data supporting robotic systems currently available is presented focussing on precision and reproducibility, radiological outcomes, clinical outcomes, and survivorship. Scientific literature published on robotic systems for knee arthroplasty was reviewed using the reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Inclusion criteria were any study involving robotic-assisted UKA or TKA that reported precision of implant positioning or functional outcomes or range of motion or survivorship, including cadaveric or dry bone studies with a minimum of 6-month follow-up. Thirty-nine studies were identified for robotic-assisted unicompartmental knee arthroplasty, and 24 studies for robotic-assisted total knee arthroplasty. Those that reported on radiological outcomes or cadaver studies consistently demonstrated improved precision with the use of robotic systems irrespective of the system. PROMS and survival data demonstrated equivalent short-term results. However, many studies reported outcomes inconsistently and few had long-term clinical follow-up or survivorship data. This review adds to the body of evidence supporting improved precision and reproducibility with robotic assistance in knee arthroplasty. Despite intensive funding of research into robotic knee systems, there remains considerable heterogeneity in exposure and outcome analysis and few quality long-term studies demonstrating translation to better clinical outcomes and implant survivorship.

Latest Advances in Robot-Assisted Knee Arthroplasty

In the longstanding pursuit of improving alignment and functional outcome in knee arthroplasty, technological evolution leading to robotic systems has now been introduced to the mainstream orthopaedic surgical world. This technology facilitates greater accuracy in implant placement, protects soft tissues, and achieves better balancing, while also allowing the potential to be more bone conserving. Robots currently in use in orthopaedic surgery can be classified into passive or haptic semi-active surgeon-guided systems. Using a virtual model of the knee joint, the robot system guides bone cuts and facilitates precise implant placement. In addition, small changes to bone resection can be made permitting deformity correction and balancing. This is achieved on-table by dynamic referencing, which enables live objective measurement of range of movements, stability, and gap balance throughout the range of motion. Preservation of ligaments and their unnecessary releases has been shown to reduce time to recovery and allow potentially better knee kinematics. Advances in robot technology in knee arthroplasty have led to the development of a variety of systems to execute the multiple steps in this procedure including using computed tomography (CT) scans, magnetic resonance imaging (MRI) scans, plain radiographs (image based), or image-free systems. The combination of these images and on-table registering of bony landmarks allow the creation of a 3-dimensional (3D) virtual, but accurate, model of the knee during surgery. The various systems apply sculpting tools, burrs, or cutting saws to deliver the bone cuts or allow robots to guide placement of cutting blocks to ensure accurate pre-planned bone cuts. Intraoperative adjustments to bone resections can be made using a variety of tracker systems to measure joint movement and ligament balance to correct any malalignments while performing the surgery, so compound errors in the technique are avoided. Data from comparative studies suggest improved accuracy in implant placement in patients compared to conventional knee arthroplasty. Benefits of robot assistance have been demonstrated both in total knee arthroplasty and unicompartmental knee arthroplasty. Recent studies show a trend toward improved patient-reported outcomes and better patient satisfactions as well as earlier recoveries following robot-assisted knee arthroplasty. Early survivorship data has also shown a better survivorship with robot-assisted knee arthroplasty, although long-term survivorship data are awaited. An increase in familiarity, availability, and demand for this technology is driving innovations aimed at delivering a personalized approach to knee arthroplasty. This chapter will discuss the latest advances and look at the clinical research in relation to the robotic technological advancement comparing some of the different system approaches.

289 Blood Loss in Robotic-Assisted Knee Arthroplasty: A Retrospective Analysis

Abstract Introduction Significant blood loss is associated with a delayed postoperative recovery in joint arthroplasty. Emerging evidence suggests robotic-assisted knee arthroplasty reduces soft-tissue trauma, length of stay, and can facilitate a faster recovery. This study compares the total blood loss in patients undergoing robotic-assisted knee arthroplasty compared to conventional methods. Method Patients undergoing robotic-assisted total knee arthroplasty (TKA) or unicomparmental knee arthroplasty (UKA) were identified using patient records. Robotic-assisted groups were compared against contemporary sex-matched controls undergoing jig-based arthroplasty. The mean total blood loss was estimated using the Gross equation. Statistical significance was identified using the Student's t-test and Mann-Whitney U test for parametric and non-parametric data, respectively. Results Robotic TKA and UKA groups were successfully matched to contemporary controls (n = 50 in all groups). No differences in preoperative haematological parameters or blood volume were found between the robotic-assisted and control groups. Robotic TKA experienced 23.7% less blood loss compared to control TKA (911.0ml vs 1193.7ml, p &amp;lt; 0.01) which was found to be statistically significant. There was a non-significant difference in mean total blood loss in robotic UKA compared to control UKA (821.7ml vs 854.7ml, p = 0.69). Conclusions The use of a robotic surgical system reduces blood loss in TKA but not UKA in knee arthroplasty.

Robotic-Assisted Patellofemoral Replacement-Correlation of Preoperative Planning with Intraoperative Implant Position and Early Clinical Experience: A Minimum 2-Year Follow-up.

Patello-femoral arthroplasty (PFA) is successful in a selected group of patients and yields a good functional outcome. Robotic-assisted knee arthroplasty has been shown to provide better implant positioning and alignment. We aim to report our early outcomes and to compare Mako's (Robotic Arm Interactive Orthopaedic System [RIO]) preoperative implant planning position to our intraoperative PFA implant position. Data for this study was prospectively collected for 23 (two bilateral) patients who underwent robotic-assisted PFA between April 2017 and May 2018. All preoperative implant position planning and postoperative actual implant position were recorded. Presence of trochlear dysplasia and functional outcome scores were also collected. There were 17 (two bilateral) female and 6 male patients with a mean age of 66.5 (range: 41-89) years. The mean follow-up period was 30 (range: 24-37) months. Eighteen knees (72%) had evidence of trochlear dysplasia. The anterior trochlear line was on average, 7.71 (range: 3.3-11.3) degrees, internally rotated to the surgical transepicondylar axis and on average 2.9 (range: 0.2-6.5) degrees internally rotated to the posterior condylar line. The preoperative planning range was 4-degree internal to 4-degree external rotation, 4-degree varus to 6-degree valgus, and 7-degree flexion to 3-degree extension. The average difference between preoperative planning and intraoperative implant position was 0.43 degrees for rotation (r = 0.93), 0.99 degrees for varus/valgus (r = 0.29), 1.26 degrees for flexion/extension (r = 0.83), and 0.34 mm for proudness (r = 0.80). Six patients (24%) had a different size component from their preoperative plan (r = 0.98). The mean preoperative Oxford Knee Score (OKS) was 16 and the mean postoperative OKS was 42. No patient had implant-related revision surgery or any radiological evidence of implant loosening at final follow-up. Our early results of robotic PFA are promising. Preoperative Mako planning correlates closely with intraoperative implant positioning. Longer follow-up is needed to assess long-term patient outcomes and implant survivorship.