Technique and first clinical results of robot-assisted total knee replacement

Clinical and patient-reported outcomes of a novel robotic system in total knee arthroplasty

BACKGROUND

Robotic assistance (RA) is increasingly used in total knee arthroplasty (TKA) for more accurate bony resection and balancing. However, the impact of robotic TKA (RATKA) on clinical outcomes and patient-reported measures (PROMs) remains unclear. This study aims to compare RATKA and conventional TKA (CTKA) using a novel robotic system.

METHODS

A retrospective review was conducted on 10,031 patients who underwent TKA from February 2021 to October 2024. 289 RATKAs were performed with a hand-held robotic system. These RATKA cases were 1:1 propensity-score matched to CTKA for patient demographics, surgeon, implant system, and articulation design. Postoperative and clinical outcomes including surgical time, length of stay (LOS), discharge disposition, 90-day emergency department (ED) visits, manipulation under anesthesia (MUA), debridement, reoperations and revisions were collected and analyzed. Patient-reported outcomes measures (PROMs) included Knee Injury and Osteoarthritis Outcome Scores (KOOS, JR) and Patient Reported Outcome Measurement Information System (PROMIS) scores.

RESULTS

RATKA demonstrated significantly shorter LOS (30.04 vs. 51.91 hours, p < 0.001, respectively) compared to CTKA. There was no difference in surgical time (107.18 vs. 106.22 minutes, p = 0.349). Although there was no statistical difference in 90-day ED visits, the majority of the CTKA revisits were due to surgery-related causes when compared to the RATKAs (1.38% vs. 0.34%, p = 0.239). While RATKAs had higher incidence of MUAs (2.07% vs. 0.34%, p = 0.201), CTKAs had more reoperations (1 vs. 0, p = 0.369) and more revisions than the RATKAs (6 vs. 0, p = 0.117). In terms of PROMs, both RATKAs and CTKAs showed similar improvements in KOOS, JR and PROMIS pain scores following TKA, with no significant differences in the magnitude of improvement at early postoperative timepoints. However, at the one-year follow-up, RATKA demonstrated significantly greater reduction in PROMIS pain intensity (Δ-9.12, p = 0.032) compared to CTKAs.

CONCLUSIONS

This retrospective analysis showed that the novel RATKA resulted in reduced length of stay, fewer reoperations, and greater reduction in one-year PROMIS pain intensity compared to CTKAs, despite having a higher incidence of MUA rates. Further research is needed to clarify these differences clinically and enhance patient outcomes.

Imageless Robotic Arm-Assisted Total Knee Arthroplasty: Workflow Optimization, Operative Times, and Learning Curve

Background Robotic arm-assisted total knee arthroplasty (RATKA) offers several advantages, including precise restoration of mechanical or kinematic alignment, accurate bone resections, reliable implant size prediction, alignment optimization, and dynamic gap balancing. However, a key concern among arthroplasty surgeons is the perceived increase in operative time associated with adopting this technology. This study describes the step-by-step surgical workflow of imageless RATKA and evaluates the surgical times and learning curve associated with this technique. Methods This study is a retrospective analysis of the data of the first 60 cases of imageless RATKA done between February 2023 and November 2024 at a single surgical center by the same surgical team. Patients undergoing imageless RATKA for Kellgren and Lawrence grade 4 osteoarthritis were included, while those with prior knee surgery or high tibial osteotomy were excluded. All procedures utilized the DePuy Attune implant with a tibia-first surgical workflow, performed via a midline vertical incision and medial parapatellar arthrotomy. Surgical times were recorded and analyzed by an independent observer not involved in the surgeries. The 60 cases were divided into four groups of 15 cases (group 1 consisted of the first 15 cases, i.e., case number 1 to case number 15; group 2 consisted of the next consecutive 15 cases, i.e., case number 16 to case number 30; group 3 consisted of case number 31 to case number 45; and group 4 consisted of the last 15 cases, i.e., case number 46 to case number 60) each to evaluate the learning curve and calculate mean surgical times. Results The surgical times (in minutes) of the various groups were as follows: group 1 (0-15 cases) = 96.27 ± 4.46; group 2 (16-30 cases) = 91.07 ± 3.75; group 3 (31-45 cases) = 88.67 ± 3.58; group 4 (46-60 cases) = 86.13 ± 3.66. Comparison of means shows p values of 0.005, 0.03, and 0.09 between group 1 and 2, group 2 and 3, and group 3 and 4, respectively, indicating normalization of the operative time and a learning curve of 15 cases.  Conclusion By following a standardized and reproducible tibia-first workflow, the operative time for imageless RATKA normalizes roughly after 15cases, i.e., group 2 onwards. This suggests that surgical time should not be a barrier for surgeons considering the adoption of this technology. The findings support the feasibility and efficiency of integrating robotic-assisted systems into routine arthroplasty practice.

Current developments in robotic assistance technology for total knee arthroplasty: a comprehensive overview

Knee arthritis is a common degenerative joint disease, usually with joint swelling, chronic pain, and dysfunction as the main clinical manifestations. At present, the conservative treatment for knee arthritis is mostly using anti-inflammatory and analgesic drugs, but the effect is mostly temporary, and can not prevent its progress and surgery is usually the last treatment method. Total knee arthroplasty, also known as TKA, is one of the most effective treatments for osteoarthritis of the knee that has progressed to the end stage. The inevitable human factor in conventional total knee arthroplasty (TKA) frequently results in poor positioning of the prosthesis during the reconstruction of the lower limb's biomechanical axis. This can lead to severe postoperative pain, accelerated wear of the prosthesis, early loosening, and other problems in the affected knee, which has always been a primary concern for orthopaedic surgeons. Over the course of the past few years, China has gradually begun to develop joint robots. The idea is to plan the surgical plan based on the anatomical structure of the affected limb before the operation, and then to use a mechanical arm and a visual system to assist in the implantation of the prosthesis while the operation is being performed. The treatment costs of robot-assisted technology, on the other hand, vary greatly, and there is still a relatively small amount of high-quality evidence on clinical efficacy. This is because the field of robotic-assisted technology is a relatively new one that has gradually developed over the past few years. In order to provide a fundamental reference for the application value of new treatment methods for advanced knee osteoarthritis, it is necessary to conduct an analysis of the current status of the application of joint robots, as well as the technical advantages and disadvantages that they bring.This narrative study delineates the historical context and current clinical application of robots in knee replacement surgery. An examination of the advantages and disadvantages of RATKA in comparison to TKA offers insights on the prospective application value of the technology.Clinical trial number: Not applicable.

Initial Experience With VELYS Robot-Assisted Total Knee Replacement: Coronal Plane Accuracy and Effect of Robotic Training on Outcomes

INTRODUCTION

The use of robots for arthroplasty is gaining momentum in recent times to provide accuracy in bony cuts and alignment. We aimed to study the efficacy of coronal plane correction with a new robotic system (VELYS™ Robotic-Assisted Surgery) and also the effect of the learning curve of robot-assisted total knee arthroplasty (RATKA) on outcomes. We hypothesize that the benefits of RATKA are not limited to only surgeons having specific training in robotic knee replacement.

MATERIALS AND METHODS

A total of 101 RATKAs were performed between November 1, 2022, and December 1, 2022, by a surgeon and all the cases were included in this study. The first 50 consecutive knees were considered as 'Cohort I' and the next 51 consecutive knees as 'Cohort II'. The intraoperative robotic registration data and tourniquet time were recorded. On three months follow‑up, Oxford Knee Score and lower limb scannogram were recorded.

RESULTS

All the 101 cases achieved the desired coronal plane alignment within 3 degrees from neutral. There was a significant difference in the tourniquet time between the two groups. There was no significant difference in the mean three months post-operative values of coronal and sagittal deformity correction, range of flexion, and Oxford Knee Score between the two groups.

CONCLUSION

The VELYS™​​​​​​​ robot-assisted system produces an accurate correction of coronal alignment. As the surgeon's experience increases with the system, there is a reduction in tourniquet time; however, the degree of deformity correction is comparable to that when he had no experience. Hence the benefits of RATKA are not limited to only surgeons having specific training in robotic-assisted knee replacement.

Robotic assisted versus conventional total knee arthroplasty: a systematic review and meta-analysis of randomised controlled trials

The aim of this study is To compare robotic-assisted and conventional total knee arthroplasty (TKA) on both short- and long-term outcomes A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, Cochrane, Scopus, and Web of Science databases were searched for relevant studies. The studies included were randomised controlled trials directly comparing robotic-assisted versus conventional TKA. The outcomes were pooled as mean difference (MD) or risk ratio (RR), with 95% confidence interval. RevMan software version 5.4 was used for performing the statistical analysis. Nine studies deemed eligible for inclusion. The data showed a significant favouring of robotic-assisted than the conventional TKA in mechanical alignment, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and femoral coronal plane outliers (MD =  - 1.10, 95% CI [- 1.51, - 0.69], p < 0.00001), (MD =  - 1.19, 95% CI [- 2.35, - 0.03], p = 0.04), and (RR = 0.49, 95% CI [0.30, 0.80], p = 0.004), respectively. On the other hand, conventional TKA was better in range of motion-flexion (long-term) than the robotic-assisted one (MD =  - 3.02, 95% CI [- 3.68, - 2.37], p < 0.00001). There were no significant differences between them in knee society score-knee score, knee society score-function score, change in hospital for special surgery (HSS) knee rating scale, and change in range of motion-extension (MD =  - 0.36, 95% CI [- 2.43, 1.70], p = 0.73), (MD =  - 0.34, 95% CI [- 2.36, 1.68], p = 0.74), (MD = 0.78, 95% CI [- 0.84, 2.40], p = 0.34), and (MD = 0.16, 95% [- 1.32, 1.64], p = 0.83), respectively. Robotic-assisted TKA demonstrated better outcomes than conventional TKA in terms of mechanical alignment and WOMAC scores. However, the conventional TKA showed a better range of motion-flexion in the long term. More data are needed to assess long-term outcomes comprehensively.

The top 100 most-cited total knee arthroplasty publications

The object is to objectively identify the 100 most influential scientific publications in total knee arthroplasty (TKA) and provide an analysis of their main characteristics. The Clarivate Analytics Web of Knowledge database was used to obtain data and metrics of TKA research. The search list was sorted by the number of citations, and articles were included or excluded based on relevance to TKA. The information extracted for each article included author name, publication year, country of origin, journal name, article type, and the level of evidence. These 100 studies generated a total of 35,399 cita- tions, with an average of 355.9 citations per article. The most-cited article was cited 1273 times. The 100 studies included in this analysis were published between 2000 and 2017. 23 different journals published these 100 publications. Majority of the publications were from United States (n = 52), followed by UK (n = 10) and Canada (n = 8). The most prevalent study designs were case series (n = 32) and cohort studies (n = 30). The 100 most influential articles in TKA were cited a total of 35,399 times. The study designs most prevalent were case series and cohort studies. This article serves as a reference to direct orthopedic surgeons to the 100 most influential studies in total knee arthroplasty. More than half of the studies are from North America, and three journals hold two-thirds of the 100 most cited publications on the topic.

Outcomes following robotic assisted total knee arthroplasty compared to conventional total knee arthroplasty

INTRODUCTION

This study elaborates on previous research to compare length of stay, complication rates, and total cost between patients undergoing robotic assisted total knee arthroplasty (rTKA) and conventional total knee arthroplasty (cTKA). We hypothesized that patients undergoing rTKA would have reduced length of stay, lower complication rates, improved perioperative outcomes, and higher total healthcare costs than those undergoing cTKA.

METHODS

Data were collected from the National Inpatient Sample Database Healthcare Cost and Utilization Project between the years 2016-2019. Patients undergoing rTKA and cTKA were identified under International Classification of Diseases, 10th revision codes (ICD-10-CM/PCS). Length of stay, specific complications, and total costs were examined at time point. SPSS (v 27.0 8, IBM Corp. Armonk, NY) was utilized to compare demographic and analytical statistics between rTKA and cTKA. rTKA and cTKA were compared both before and after propensity matching.

RESULTS

17,249 rTKA (3.09%) and 541,122 cTKA (96.91%) were included. Compared to cTKA patients, rTKA patients had reduced average length of stay of 1.91 days (p < 0.001), higher average total cost of $67133.34 (p < 0.001), reduced periprosthetic infection (OR = 0.027, p < 0.001), periprosthetic dislocation (OR = 0.117, p < 0.001), periprosthetic mechanical complication (OR = 0.315, p < 0.001), pulmonary embolism (OR = 0.358, p < 0.001), transfusion (OR = 0.366, p < 0.001), pneumonia (OR = 0.468, p = 0.002), deep vein thrombosis (OR = 0.479, p = 0.001), and blood loss anemia (OR = 0.728, p < 0.001). These differences remained statistically significant even after propensity matching.

CONCLUSIONS

This study supports our hypothesis that rTKA is associated with fewer complications, but higher average total cost than cTKA. Our study shows that rTKA can be safely performed in older and sicker patients. Future studies assessing the impacts of these findings on patient reported outcomes would provide further insight into the benefits of rTKA. Furthermore, identifying patient specific factors that place them at risk for increased complications with cTKA as opposed to rTKA could provide surgeons insight on the method of TKA that maximizes patient outcomes while minimizing healthcare cost.

Operating room efficiency for a high-volume surgeon in simultaneous bilateral robotic-assisted total knee arthroplasty: a prospective cohort study

Robotic-assisted total knee arthroplasty (RATKA) has been shown to achieve more accurate component positioning and target alignment than conventional jig-based instrumentation; however, concerns remain regarding its adoption since it is associated with steep learning curves, higher operational costs, and increased surgical time. This study aims to compare the operating times of three cohorts of patients undergoing simultaneous bilateral TKA, i.e., first 50 RATKA, last 50 RATKA (at the end of 1 year), and 50 conventional TKA. This prospective cohort study was conducted at a single high-volume tertiary care center by a single experienced surgeon on 150 patients (300 knees), who were allotted into three equal cohorts of 50, between February 2020 and December 2021. Simultaneous bilateral TKAs were done in all three groups and operative times recorded. We describe the technique for optimizing the surgical time of SB-RATKA for efficient operative room logistics. The operating times of the two robotic-assisted TKA cohorts were compared with the operating times of the conventional SB-TKA cohort. The mean age of the study population was 59(±6.2) years with the majority of females (82%). The mean coronal deformity was comparable between the cohorts. The mean operating time in the conventional CTKA, initial 50 RATKA, and final 50 RATKA cohorts were 115.56 (±10.7), 127.8 (±26), and 91.66 (±13.5) min, respectively, all of which showed a statistically significant difference (p < 0.001). The mean operating times of the final 50 RATKA at the end of 1 year improved by about 36 min with all the SB-RATKA cases being completed in under 120 min. The efficiency of SB-RATKA improved significantly with time and experience, resulting in shorter operational times within a year, revealing the potential of robotic-assisted surgery to surpass conventional approaches in TKA in terms of operating room efficiency.

Robotic-Assisted Total Knee Arthroplasty in Obese Patients

Background

Robotic-assisted systems have gained popularity in total knee arthroplasty (TKA). The purpose of this study was to evaluate operative characteristics and radiographic outcomes of obese patients undergoing robotic-assisted TKA.

Methods

A retrospective review of consecutive cases performed by a single surgeon was performed from January 1, 2016, to January 31, 2022. Adult patients with body mass index ≥35 kg/m2 who underwent primary TKA using a computed tomography-assisted robotic system were compared to patients who underwent primary TKA using conventional instrumentation. Demographics, preoperative and postoperative radiographic measurements, and intraoperative outcomes were compared between cohorts. In total, 119 patients were identified, 60 in the robotic-assisted cohort and 59 in the conventional instrumentation cohort.

Results

Age, body mass index, and estimated blood loss were not significantly different between the cohorts. The robotic-assisted cohort experienced longer tourniquet times (93.3 vs 75.5 minutes, P < .001). Preoperative hip-knee-ankle angle (HKA) was similar between the robotic-assisted and conventional cohorts (8.4° ± 4.9° vs 9.3° ± 5.3°, P = .335). Postoperative HKA was 2.0° ± 1.4° in the robotic-assisted group and 3.1° ± 3.23° in the conventional group (P = .040). The proportion of patients with postoperative HKA > 3° of varus or valgus was 9 of 60 (15.0%) in the robotic-assisted cohort compared to 18 of 59 (30.5%) using conventional instrumentation (P = .043).

Conclusions

Obese patients treated with robotic-assisted TKA had postoperative alignment closer to neutral and fewer postoperative radiographic outliers than patients treated with conventional instrumentation. The results of this study support use of robotic-assisted technologies in TKA, particularly in obese patients.

Disparities in Access to Robotic Knee Arthroplasty: A Geospatial Analysis

BACKGROUND

The utilization of robotic knee arthroplasty (RKA) continues to increase across the United States. The aim of this geospatial analysis was to elucidate if RKA is distributed uniformly across the United States or if disparities exist in patient access.

METHODS

Publicly available provider-finding functions for 5 major manufacturers of RKA systems were used to obtain the practice locations of surgeons performing RKA along with their associated RKA system manufacturer. The average travel distance for each county to the nearest RKA surgeon was calculated and Moran's index clustering analysis was used to find hotspots and coldspots of RKA access. A logistic regression model was used to identify the predictive odds ratios between robotic hotspots and coldspots with county-level sociodemographic variables. Of the 34,216 currently practicing orthopedic surgeons in 2022, 2,571 have access to robotic assistance for knee arthroplasty.

RESULTS

Hotspots of increased travel time were predominantly in West South Central and West North Central census regions. Hotspots were significantly more rural and consisted of predominantly White populations, with lower median income and health insurance coverage.

CONCLUSIONS

The results of the current study align with existing literature, demonstrating absolute geographic access disparities for rural and economically disadvantaged populations. Additionally, relative access disparities persist for minority populations and individuals with high comorbidity burdens residing in urban areas.

Robotic-Assisted Hip and Knee Arthroplasty: A Bibliometric Analysis Using the Scopus Database

Robotic-assisted hip and knee arthroplasty represents cutting-edge advancements in orthopedic surgery, harnessing robotic technology to enhance precision, improve clinical outcomes, and facilitate intra-operative procedures. In these robotic-assisted surgeries, the robotic systems assist surgeons in planning and executing joint replacement surgeries, thereby facilitating personalized implant positioning and optimizing the fit and alignment of hip and knee implants. Despite the increasing attention garnered by robotic-assisted hip and knee arthroplasty in recent years, a comprehensive bibliometric analysis using the Scopus database has yet to be conducted. This bibliometric analysis reviews the Scopus database from 1961 until 2022 to investigate the literature on the field of robotic-assisted hip and knee arthroplasty. A total of 577 articles that satisfied the selection criteria were included in this review. The majority of the articles focus more on total knee replacement, compared to total hip replacement and unicompartmental knee arthroplasty. The overwhelming majority of the articles were authored by researchers and clinicians from the United States of America (USA) and the United Kingdom (UK). Similarly, most of the articles with the highest number of citations were authored by researchers and clinicians from these regions. This comprehensive bibliometric analysis using Scopus in the domain of robotic-assisted hip and knee replacement has the potential to act as a roadmap for researchers, clinicians, and policymakers, facilitating informed decision-making, promoting collaborative initiatives, and guiding the development of future studies to further advance the field of robotic-assisted hip and knee arthroplasty.

Robotic-assisted TKA is Not Associated With Decreased Odds of Early Revision: An Analysis of the American Joint Replacement Registry

BACKGROUND

Robotic-assisted TKA continues to see wider clinical use, despite limited knowledge of its impact on patient satisfaction and implant survival. Most studies to date have presented small cohorts and came from single-surgeon or single-center experiences. Therefore, a population-level comparison of revision rates between robotic-assisted and conventional TKA in the registry setting may help arthroplasty surgeons better define whether robotic assistance provides a meaningful advantage compared with the conventional technique.

QUESTIONS/PURPOSES

(1) After controlling for confounding variables, such as surgeon, location of surgery, and patient comorbidity profile, were robotic-assisted TKAs less likely than conventional TKAs to result in revision for any reason at 2 years? (2) After again controlling for confounding variables, were robotic-assisted TKAs less likely to result in any specific reasons for revision than the conventional technique at 2 years?

METHODS

The American Joint Replacement Registry was used to identify patients 65 years or older who underwent TKA between January 2017 and March 2020 with a minimum of 2 years of follow-up. Patients were limited to age 65 yeas or older to link TKAs to Medicare claims data. Two retrospective cohorts were created: robotic-assisted TKA and conventional TKA. Patient demographic variables included in the analysis were age, gender, BMI, and race. Additional characteristics included the Charlson comorbidity index, anesthesia type, year of the index procedure, and length of stay. A total of 10% (14,216 of 142,550) of TKAs performed during this study period used robotics. Patients with robotic-assisted TKA and those with conventional TKA were similar regarding age (73 ± 6 years versus 73 ± 6 years; p = 0.31) and gender (62% [8736 of 14,126] versus 62% [79,399 of 128,334] women; p = 0.34). A multivariable, mixed-effects logistic regression model was created to analyze the odds of all-cause revision as a factor of robot use, and a logistic regression model was created to investigate specific revision diagnoses.

RESULTS

After controlling for potentially confounding variables, such as surgeon, location of surgery, and Charlson comorbidity index, we found no difference between the robotic-assisted and conventional TKAs in terms of the odds of revision at 2 years (OR of robotic-assisted versus conventional TKA 1.0 [95% CI 0.8 to 1.3]; p = 0.92). The reasons for revision of robotic-assisted TKA did not differ from those of conventional TKA, except for an increased odds of instability (OR 1.6 [95% CI 1.0 to 2.4]; p = 0.04) and pain (OR 2.1 [95% CI 1.4 to 3.0]; p < 0.001) in the robotic-assisted cohort.

CONCLUSION

In light of these findings, surgeons should not assume that robotic assistance in TKA will lead to improved early implant survival. Our findings do not support an improvement over conventional TKA with robotic assistance with regards to common causes of early revisions such malalignment, malposition, stiffness, pain, and instability, and in some cases, suggest there is a benefit to conventional TKA. Differences in the mid-term and long-term revision risk with conventional versus robotic-assisted TKA remain unknown. Appropriate informed consent around the use of robotic assistance should not imply decreased early revision risk.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Intra-operative Safety of an Autonomous Robotic System for Total Knee Replacement: A Review of 500 Cases in India

Background

Manual total knee arthroplasty (TKA) has been documented several times for their safety and complications data. In contrast, there is a limited evidence-based analysis for safety and complications of autonomous robotic-assisted (RA)-TKA. This study aimed to evaluate the safety features and intra-operative surgical complications associated with the use of Cuvis Joint™ autonomous robotic system for TKA.

Methods

The study included 500 consecutive patients who underwent TKA using the Cuvis Joint™ autonomous robotic system from November 2020 to November 2021. All surgeries were performed by a senior surgeon. Patients in whom the surgery was abandoned midway due to technical errors, were excluded from the analysis. In case of unilateral abandonment of the robotic arm during a bilateral RA-TKA, data of the side on which the surgery was completed with robotic assistance was recorded.

Results

There was no incidence of neurological injury, vascular injury, extensor mechanism disruption, or medial collateral ligament injury. There was one case of superficial abrasion of the patellar tendon; however, it did not require any intervention. There were no cases of midway abandonment due to threatened soft tissue injury. There was no intra-operative pin loosening or stress-related fractures at the pin sites. There was one case of Steinmann pin breakage and another case of drill bit breakage, which were removed without any damage to the bone.

Conclusion

The Cuvis Joint™ autonomous robotic system for TKA is safe with no significant intra-operative complications.

Robotic-assisted mechanically aligned total knee arthroplasty does not lead to better clinical and radiological outcomes when compared to conventional TKA: a systematic review and meta-analysis of randomized controlled trials

PURPOSE

Robotic-assisted total knee arthroplasty (R-TKA) has emerged as an alternative to improve the results of the conventional manual TKA (C-TKA). The aim of this study was to analyse the high-level studies comparing R-TKA and C-TKA in terms of clinical outcomes, radiological results, perioperative parameters, and complications.

METHODS

The literature search was conducted on three databases (PubMed, Cochrane, and Web of Science) on 1 February 2023 according to the guidelines for Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). Inclusion criteria were: randomized controlled trials (RCTs), written in English language, published in the last 15 years, focusing on the comparison of C-TKA and R-TKA results. The quality of each article was assessed using the Cochrane risk-of-bias tool for randomized trials version 2 (RoB 2). The statistical analysis was carried out using random effects (DerSimonian & Laird) for weighted mean difference (MD) of the continuous variables and Peto method for odds ratios of the dichotomous variables.

RESULTS

Among the 2905 articles retrieved, 14 RCTs on 12 series of patients treated with mechanically aligned implants were included. A total of 2255 patients (25.1% males and 74.9% females; mean age 62.9 ± 3.0; mean BMI 28.1 ± 1.3) were analysed. The results of this systematic review and meta-analysis showed that R-TKA did not provide overall superior results compared to C-TKA in mechanically aligned implants in terms of clinical and radiological outcomes. R-TKA showed longer operative time (MD = 15.3 min, p = 0.004) and similar complication rates compared to C-TKA. A statistically significant difference in favour of R-TKA was found in the posterior-stabilized subgroup in terms of radiological outcomes (hip-knee-ankle angle MD = 1.7, p < 0.001) compared to C-TKA, although without resulting in appreciable difference of clinical outcomes.

CONCLUSION

R-TKA did not provide overall superior results compared to C-TKA in terms of clinical and radiological outcomes, showing longer operative time and similar complication rates.

LEVEL OF EVIDENCE

Level I.

[Translated article] Current situation of robotics in knee prosthetic surgery: A technology that has come to stay?

Robotic surgery is a surgical technique that is on the rise. The goal of robotic-assisted total knee arthroplasty (RA-TKA) is to provide the surgeon with a tool to accurately execute bone cuts according to previous surgical planning to restore knee kinematics and balance of soft tissue, being able to precisely apply the type of alignment that we choose. In addition, RA-TKA is a very useful tool for training. Within the limitations, there is the learning curve, the need for specific equipment, the high cost of the devices, the increase in radiation in some systems and that each robot is linked to a specific type of implant. Current studies show, with RA-TKA, variations in the alignment of the mechanical axis are reduced, postoperative pain is improved and earlier discharge is facilitated. On the other hand, there are no differences in terms of range of motion, alignment, gap balance, complications, surgical time or functional results.

Learning curve and short-term clinical outcomes of a new seven-axis robot-assisted total knee arthroplasty system: a propensity score-matched retrospective cohort study

OBJECTIVE

The purpose of the present study was to determine the learning curve for a novel seven-axis robot-assisted (RA) total knee arthroplasty (TKA) system and to explore whether it could provide superior short-term clinical and radiological outcomes compared with conventional surgery.

METHODS

In the present retrospective study, 90 patients who underwent RA-TKA were included in robot-assisted system (RAS) group and 90 patients who underwent conventional TKA were included in the conventional group. The duration of surgery and robot-related complications were recorded to evaluate the learning curve through cumulative sum and risk-adjusted cumulative sum methods. The demographic data, preoperative clinical data, preoperative imaging data, duration of surgery, alignment of the prosthesis, lower limb force line alignment, Knee Society score, 10-cm visual analog scale pain score and range of motion were compared between the RAS and conventional groups. In addition, the proficiency group was compared with the conventional group using propensity score matching.

RESULTS

RA-TKA was associated with a learning curve of 20 cases for the duration of surgery. There was no significant difference in indicators representing the accuracy of the prosthetic installation between the learning and proficiency phases in RA-TKA group patients. A total of 49 patients in the proficiency group were matched with 49 patients from the conventional group. The number of postoperative hip-knee-ankle (HKA) angle, component femoral coronal angle (CFCA), component tibial coronal angle (CTCA), and sagittal tibial component angle (STCA) outliers in the proficiency phase was lower than that in the conventional group, while deviations of the HKA angle, CFCA, CTCA, and STCA in the proficiency phase were significantly lower than those in the conventional group (P < 0.05).

CONCLUSION

In summary, from the learning curve data, 20 cases are required for a surgeon using a novel seven-axis RA-TKA system to enter the proficiency phase. In the proficiency group, compared with the conventional group using propensity score matching, the RAS was found to be superior to the conventional group in prosthesis and lower limb alignment.

Clinical evaluation of the first semi-active total knee arthroplasty assisting robot made in China: a retrospective propensity score-matched cohort study

OBJECTIVE

The precision of overall alignment and knee morphotype after robot-assisted total knee arthroplasty has been fully confirmed. This study aims to conduct a clinical evaluation of the first China-made semi-active total knee arthroplasty assisting robot.

METHODS

After a 1 : 2 propensity score matching, that is, a matched cohort study, patients were matched to the robot group (52 cases) and the conventional group (104 cases). The robot group received osteotomy according to preoperative planning, while the conventional group adopted preoperative planning based on the full-length radiograph and received conventional osteotomy. Perioperative clinical indicators, such as operation time, tourniquet time, hospitalization days, intraoperative bleeding, and hemoglobin level of the two groups were recorded; radiological indicators of postoperative prosthesis position, including hip-knee-ankle angle, frontal femoral component angle, frontal tibial component angle, lateral femoral component angle, and lateral tibial component angle were also recorded; deviations and outliers of the radiological indicators were calculated.

RESULTS

Compared with the conventional group, the operation time and tourniquet time of the robot group were longer, and the postoperative hemoglobin level decreased less, the differences were statistically significant; the lateral tibial component angle of the conventional group was 80.9°±3.6°, which was smaller than 86.7 °±2.3° of the robot group, the difference was statistically significant ( P <0.001); except for lateral femoral component angle, the absolute deviations of the radiological indicators in the robot group were significantly smaller than that in the conventional group ( P ≤0.001); the outliers of the radiological indicators in the robot group were significantly smaller than that in the conventional group with a statistical difference ( P <0.05).

CONCLUSION

Compared with the conventional group, the operation time of the robot group was relatively longer, but the perioperation blood loss was less. The robot group could better control the posterior inclination of the tibial prosthesis, and the absolute deviations and outliers of the prosthesis position were relatively smaller. There was no difference in short-term clinical score between the two groups.

Challenges of Integrating New Technologies for Orthopedic Doctors to Face up to Difficulties during the Pandemic Era

In the field of orthopedics, competitive progress is growing faster because new technologies used to facilitate the work of physicians are continuously developing. Based on the issues generated in the pandemic era in this field, a research study was developed to identify the intention of orthopedic doctors to integrate new medical technologies. The survey was based on a questionnaire that was used for data collection. The quantitative study registered a sample of 145 orthopedic doctors. The data analysis was performed based on the IBM SPSS program. A multiple linear regression model was applied, which analyzed how the independent variables can influence the dependent variables. After analyzing the data, it was observed that the intention of orthopedic doctors to use new medical technologies is influenced by the advantages and disadvantages perceived by them, the perceived risks, the quality of the medical technologies, the experience of physicians in their use, and their receptivity to other digital tools. The obtained results are highly important both for hospital managers and authorities, illustrating the main factors that influence doctors to use emergent technologies in their clinical work.

Overcoming Challenges and Innovations in Orthopedic Prosthesis Design: An Interdisciplinary Perspective

Recent advances in the orthopedic prostheses design have significantly improved the quality of life for individuals with orthopedic disabilities. However, there are still critical challenges that need to be addressed to further enhance the functionality of orthopedic prostheses improving biocompatibility to promote better integration with natural tissues, enhancing durability to withstand the demands of daily use, and improving sensory feedback for better control of movement are the most pressing issues. To address these challenges, promising emerging solutions such as smart prosthetics, 3D printing, regenerative medicine, and artificial intelligence have been developed. These innovative technologies hold the potential to significantly enhance the functionality of orthopedic prostheses. Realizing the full potential of these next-generation orthopedic prostheses requires addressing several critical factors. These include interdisciplinary collaboration between experts in orthopedics, materials science, biology, and engineering, increased investment in research and development, standardization of components to ensure quality and reliability, and improved access to prosthetics. A comprehensive review of these challenges and considerations for future orthopedic prosthesis design is s provided in this paper addressing the further advances to the field. By addressing these issues, we can continue to improve the lives of individuals with orthopedic disabilities and further enhance the field of orthopedic prosthetics.

Complications and downsides of the robotic total knee arthroplasty: a systematic review

PURPOSE

The purpose of this systematic review is to describe the complications and downsides of robotic systems in total knee arthroplasty (TKA).

METHODS

A comprehensive search according to the PRISMA guidelines was performed across PubMed, MEDLINE, Cochrane Central Register of Controlled Trials, Scopus, and Google Scholar from inception until December 2021. All articles of any study design directly reporting on complications and downsides of the robotic system in TKA were considered for inclusion. Risk of bias assessment was performed for all included studies using the Cochrane risk of bias and MINORS score.

RESULTS

A total of 21 studies were included, consisting of 4 randomized controlled trials, 7 prospective studies and 10 retrospective studies. Complications of the robotic system were pin-hole fracture, pin-related infection, iatrogenic soft tissue and bony injury, and excessive blood loss. While, downsides were longer operative duration, higher intraoperative cost, learning curve and aborting a robotic TKA due to different reasons. Iatrogenic injuries were more common in the active robotic system and abortion of the robotic TKA was reported only with active robotic TKA.

CONCLUSION

Robotic TKA is associated with certain advantages and disadvantages. Therefore, surgeons need to be familiar with the system to use it effectively. Widespread adoption of the robotic system should always be evidence-based.

LEVEL OF EVIDENCE

IV.

Comparative assessment of current robotic-assisted systems in primary total knee arthroplasty

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.

The Accuracy of Computed Tomography-Based, Three-Dimensional Implant Planning in Robotic-Assisted Total Knee Arthroplasty

Advanced imaging used in robotic-assisted total knee arthroplasty (TKA), such as computed tomography (CT)-based three-dimensional (3D) planning, may provide an accurate means of implant sizing preoperatively. The purpose of this study was to examine preoperative CT-based implant planning accuracy for robotic-assisted TKA in patients who have (1) varus deformities, (2) valgus deformities, (3) neutral alignment, and (4) retained hardware. A total of 393 patients underwent a robotic-assisted TKA by a single surgeon received preoperative CT scans. The surgeon reviewed the CT-based model preoperatively and recorded the expected size of the components. The final implants used in each case were recorded and compared with the surgeon's preoperative plan. In all groups of patients, the surgeon's CT-based implant plan was within one size of the implant utilized 100% of the time for both the tibiae and femora. Overall, the surgeon was exactly matched in 319 (81%) and 315 (80%) cases for the femoral and tibial components, respectively. For the femoral component, the mean age for patients in whom the original plan was exactly matched was younger than those whose implants were upsized and older than patients those implants were downsized (p = 0.024). Other patient demographics and preoperative knee alignment were not associated with predictive accuracy for femoral or tibial components. Our results demonstrate how preoperative CT-based, 3D planning for robotic-assisted TKA is accurate to within one size of the components in every case (100%), and exactly matched in 80%. The results of this study are important because they demonstrate how CT-based preoperative implant planning for TKA is reliable and accurate across all native knee alignments and other patient-specific factors. In addition, they build on a previous study by the same single surgeon, demonstrating that predictive ability can improve over time. This may be important as we move toward more outpatient surgery with less ability for prostheses inventory at ambulatory sites.

Characteristics and trends of the most cited papers in robotic assisted arthroplasty

Purpose

To compile and analyze the top 50 most frequently cited articles published on robotic-assisted arthroplasty, allowing clinicians to effectively identify the most influential literature pertaining to this topic.

Methods

Guidelines set by the Preferred Reporting Items for Systematic Reviews were used as the foundation for data collection and analysis. All papers pertaining to robotic-assisted arthroplasty were retrieved using the Scopus database. Data including: manuscript title, authors, total citation count, level of evidence, journal, publication year, and country of publication was extracted from a final list of articles.

Results

The top 50 publications regarding robotic assisted arthroplasty were cited a total of 4530 times (including self-citations), with an average total of 91. The years with the most publications in the top 50 were: 2017, 2018, and 2019, producing 7, 6, and 5 papers, respectively. Only 4 papers in the top 50 were published prior to the year 2003. The most common level of evidence was level V, and the most common category was Clinical Outcomes (74%). The United States contributed half of the 50 articles, and Princess Grace Hospital and University of London were the most contributory institutions, each with 6 of the top 50 articles.

Conclusion

This analysis provides a comprehensive review of the most cited and influential papers in robotic-assisted arthroplasty. Understanding these trends in the literature will ultimately pave the way for physicians and researchers to continue to innovate and research in a targeted manner as they gain an understanding of what has been studied and what remains inadequately explored.

Level of evidence

3.

Robot-assisted surgery in total knee arthroplasty: trauma maker or trauma savior? A prospective, randomized cohort study

BACKGROUND

Robotic assistance has been increasingly employed to improve the operative precision in modern knee surgery. The purpose of the study was to evaluate the trauma effect of one of the first domestically developed orthopedic surgical robots in China in a clinical trial of robot-assisted total knee arthroplasty (RA-TKA).

METHODS

A total of 33 patients who underwent unilateral TKA for end-stage osteoarthritis were randomized to receive RA-TKA (17 cases) or conventional manual TKA (CM-TKA) in our institution in 2020. The trauma effects of the 4 main indicators with 48 sub-indicators in terms of subsectional operative time, inflammation and coagulation markers, physical and radiographical analyses of osteotomy deviation, and postoperative comfort were analyzed.

RESULTS

Subsectional operative time analysis showed that the times for bone cutting and gap balancing with RA-TKA were 5.3 and 2.2 min shorter than those with CM-TKA (p = 0.010, p = 0.02), respectively. Arterial blood gas indicators (partial pressure of carbon dioxide, partial pressure of oxygen and SO₂) 24 h after RA-TKA, as well as the white blood cell count and neutrophil ratio, were significantly lower than those after CM-TKA (p < 0.05). Inflammatory markers at 72 h after surgery showed the increments of C-reactive protein, erythrocyte sedimentation rate and D-dimer of RA-TKA declined by 180.7, 22.0 and 1050.0% (p < 0.05), respectively, referenced to the preoperative baseline values, as compared to CM-TKA. Mechanical deviation distribution exhibited percentages of region I errors for RA-TKA and CM-TKA of 76.5% and 27.1% (p = 0.000), respectively, and the success rates of one-time osteotomy were 94.1% and 62.5% (p = 0.039), respectively. Radiographical verification showed RA-TKA was more conducive to achieving mechanical alignment and ideal tibial component azimuths. Postoperative efficacy showed that patients were more comfortable after RA-TKA in terms of reduced administration of tranexamic acid, hydrocortisone and the utilization rate of temporary intensive opioid analgesics. No statistical difference in patient-reported outcome measures and complications were recorded between the two groups during continuous observation.

CONCLUSIONS

Compared with CM-TKA, RA-TKA decreases rather than increases trauma. It might shorten the time required for bone cutting and gap balancing, reduce mechanical errors related to the osteotomy and prosthesis position, and improve the accuracy of the mechanical alignment reconstruction. RA-TKA is also favorable in promoting postoperative comfort and minimizing inflammatory response and drug consumption.

TRIAL REGISTRATION

The Chinese Clinical Trial Registry (ChiCTR2000031282) approved registration on 26 March 2020.

[Future implications of navigation in total knee arthroplasty]

BACKGROUND

After more than two decades of experience with computer-assisted knee arthroplasty, extensive experience and study data are available, allowing a profound 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.

LONG-TERM OUTCOME

Further, international registries show advantages of computer-assisted knee arthroplasty regarding long-term outcomes. In particular, the Australian arthroplasty registry describes a significantly lower revision rate due to aseptic loosening/osteolysis in the computer-assisted knee arthroplasty group, analyzing a period of up to 17 years. These positive effects can already be proven six months following surgery.

FUTURE PROSPECTS

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 a difficult task.

[Market overview: Robotic-assisted arthroplasty : Current robotic systems, learning curve and cost analysis]

Robotic-assisted arthroplasty has been rapidly entering clinical routine in recent years. The leading endoprosthesis manufacturers have all meanwhile placed robotic systems on the market, which, however, differ significantly from one another technically. Current systems are currently classified according to the degree of autonomy (active vs. semi-active vs. passive) and the data/image source (image-based: CT vs. X‑ray, imageless). Some systems already offer the possibility of robotic-assisted or navigated implantation of hip endoprostheses. In the following review article, the currently leading robotic systems will be presented and compared with regard to their characteristics. Furthermore, the analysis of the learning curves for the different systems, currently available cost analysis models and an outlook on future developments and challenges will be given.

Robotic-Arm Assisted Technology's Impact on Knee Arthroplasty and Associated Healthcare Costs

Background: The number of total knee arthroplasties (TKA) carried out globally is expected to substantially rise in the coming decades. Consequently, focus has been increasing on improving surgical techniques and minimizing expenses. Robotic arm-assisted knee arthroplasty has garnered interest to reduce surgical errors and improve precision. Objectives: Our primary aim was to compare the episode-of-care cost up to 90 days for unicompartmental knee arthroplasty (UKA) and TKA performed before and after the introduction of robotic arm-assisted technology. The secondary aim was to compare the volume of UKA vs TKA. Methods: This was a retrospective study design at a single healthcare system. For the cost analysis, we excluded patients with bilateral knee arthroplasty, body mass index >40, postoperative infection, or noninstitutional health plan insurance. Costs were obtained through an integrated billing system and affiliated institutional insurance company. Results: Knee arthroplasty volume increased 28% after the introduction of robotic-assisted technology. The TKA volume increased by 17%, while the UKA volume increased 190%. Post introduction, 97% of UKA cases used robotic arm-assisted technology. The cost analysis included 178 patients (manual UKA, n = 6; robotic UKA, n = 19; manual TKA, n = 58, robotic TKA, n = 85). Robotic arm-assisted TKA and UKA were less costly in terms of patient room and operating room costs but had higher imaging, recovery room, anesthesia, and supply costs. Overall, the perioperative costs were higher for robotic UKA and TKA. Postoperative costs were lower for robotic arm-assisted surgeries, and patients used less home health and home rehabilitation. Discussion: Surgeons performed higher volumes of UKA, and UKA comprised a greater percentage of total surgical volume after the introduction of this technology. The selective cost analysis indicated robotic arm-assisted technology is less expensive in several cost categories but overall more expensive by up to $550 due to higher cost categories including supplies and recovery room. Conclusions: Our findings show a change in surgeons' practice to include increased incidence and volume of UKA procedures and highlights several cost-saving categories through the use of robotic arm-assisted technology. Overall, robotic arm-assisted knee arthroplasty cost more than manual techniques at our institution. This analysis will help optimize costs in the future.

Virtual and Real Bidirectional Driving System for the Synchronization of Manipulations in Robotic Joint Surgeries

Surgical robots are increasingly important in orthopedic surgeries to assist or replace surgeons in completing operations. During joint surgeries, the patient’s joint needs to be adjusted several times by the surgeon. Therefore, the virtual model, built on the preoperative medical images, cannot match the actual variation of the patient’s joint during the surgery. Conventional virtual reality techniques cannot fully satisfy the requirements of the joint surgeries. This paper proposes a real and virtual bidirectional driving method to synchronize the manipulations in both the real operation site and the virtual scene. The dynamic digital twin of the patient’s joint is obtained by decoupling the joint and dynamically updating its pose via the intraoperative measurements. During surgery, the surgeon can intuitively monitor the real-time position of the patient and the surgical tool through the system and can also manipulate the surgical robot in the virtual scene. In addition, the system can provide visual guidance to the surgeon when the patient’s joint is adjusted. A prototype system is developed for orthopedic surgeries. Proof-of-concept joint surgery demo is carried out to verify the effectiveness of the proposed method. Experimental results show that the proposed system can synchronize the manipulations in both the real operation site and the virtual scene, thus realizing the bidirectional driving.

Comparative outcomes between a new robotically assisted and a manual technique for total knee arthroplasty in patients with osteoarthritis: a prospective matched comparative cohort study

PURPOSE

Studies comparing clinical outcomes between manual (mTKA) and robotic-assisted TKA (raTKA) are limited. This prospective comparative cohort study aimed to compare early postoperative outcomes, satisfaction, and patient-reported outcome measures (PROMS) between patients undergoing mTKA and ROSA raTKA (Zimmer Biomet, Warsaw, IN) performed by one surgeon.

METHODS

Thirty ROSA raTKAs and 30 mTKAs performed by one surgeon during 2020-2021 were prospectively evaluated. Groups were matched for age, sex, and body mass index. All procedures were primary unilateral TKAs using the same posterior-stabilized prosthesis (Nexgen Legacy, Zimmer Biomet, Warsaw, IN). Length of hospital stay (LOS) and blood transfusion rate were recorded. Complications, visual analogue scale score (VAS), and Oxford Knee Score (OKS) were assessed preoperatively and for six postoperative months. The Forgotten Joint Score (FJS) and patient satisfaction were evaluated 6 months postoperatively.

RESULTS

No complications and similar blood transfusion rate were recorded between groups (p = 0.228). The LOS was non-significantly shorter in raTKA than in the mTKA group (p = 0.120). Mean preoperative and third-month OKS and VAS scores were comparable between groups. However, the mean 6-month OKS (p = 0.006) and VAS score (p = 0.025) were significantly better for the raTKA group. The 6-month FJS was significantly greater for raTKA than the mTKA group (p < 0.001). One patient was unhappy in raTKA, and three in the mTKA group (p = 0.301). Significantly more raTKA patients answered that they would undergo surgery again (p = 0.038).

CONCLUSION

raTKA was associated with the same complication risk, less pain level, better patient satisfaction, and PROMs on 6-month follow-up than the mTKA group.

Robotic arm-assisted arthroplasty: The latest developments

Joint arthroplasty is an effective method for treating end-stage joint lesions and damages. Robotic arm-assisted arthroplasty, a rapidly developing technology that combines navigation technology, minimally invasive technology, and precise control technology of the robotic arm, can achieve accurate preoperative planning, optimal selection of implants, minimally invasive surgery, precise osteotomy, and accurate placement of the artificial joint. It has the characteristics of high accuracy and stability, and thus is more and more widely used in the field of joint surgery. In this paper, we systematically reviewed the application and clinical efficacy of robotic arm-assisted technology in hip and knee arthroplasty to provide reference for its future promotion.

Learning Curve of Robotic-Assisted Total Knee Arthroplasty for a High-Volume Surgeon

The learning curve has been established for robotic-assisted total knee arthroplasty (RATKA) during the first month of use; however, there have been no studies evaluating this on a longer term. Therefore, the purpose of this study was to compare operative times for three cohorts during the first year following adoption of RATKA (initial, 6 months, and 1 year) and a prior cohort of manual TKA. We investigated both mean operative times and the variability of operative time in each cohort. This is a learning curve study comparing a single surgeon's experience using RAKTA. The study groups were made up of two cohorts of 60 cementless RATKAs performed at ∼6 months and 1 year of use. A learning curve was created based on the mean operative times and individual operative times were stratified into different cohorts for comparison. Study groups were compared with the surgeon's initial group of 20 cemented RATKAs and 60 cementless manual cases. Descriptive numbers were compiled and mean operative times were compared using Student's t-tests for significant differences with a p-value of < 0.05. The mean surgical times continued to decrease after 6 months of RATKA. In 1 year, the surgeon was performing 88% of the RATKA between 50 and 69 minutes. The initial cohort and 1-year robotic-assisted mean operative times were 81 and 62 minutes, respectively (p < 0.00001). Mean 6-month robotic-assisted operative times were similar to manual times (p = 0.12). A significant lower time was found between the mean operative times for the 1-year robotic-assisted and manual (p = 0.008) TKAs. The data show continued improvement of operative times at 6 months and 1 year when using this new technology. The results of this study are important because they demonstrate how the complexity of a technology which initially increases operative time can be overcome and become more time-effective than conventional techniques.

Effect of tourniquet use on blood loss, pain, functional recovery, and complications in robot-assisted total knee arthroplasty: a prospective, double-blinded, randomized controlled trial

Background

Robot-assisted total knee arthroplasty (TKA) has been largely studied to confirm its advantages in terms of accurate component positioning, microembolus formation, less blood loss, and so on, but is currently usually performed under tourniquet due to its longer operative time than conventional TKA. The aim of this study was to estimate the effects of tourniquet use in robot-assisted TKA on blood loss, pain, functional recovery, and complications.

Methods

Patients scheduled for robot-assisted TKA were prospectively randomized into a tourniquet or non-tourniquet group (each n = 14). The primary outcome measure was blood loss. The secondary outcome measures were operation time; visual analog scale (VAS) pain scores; time to achieve the first straight-leg raise; swelling of the thigh, knee, and calf; range of motion; Hospital for Special Surgery score; length of stay; and postoperative complications.

Results

There was no significant difference in total blood loss between the tourniquet and non-tourniquet groups (738.57 ± 276.158 vs. 866.85 ± 243.422 ml, P = 0.061). The tourniquet group showed significantly lower intraoperative blood loss (P < 0.001), but higher hidden blood loss (P = 0.002). The non-tourniquet group showed better knee range of motion on postoperative days (PODs) 1–3 (all P < 0.001), less thigh swelling on PODs 2 and 3 (P < 0.05), earlier straight-leg raising (P = 0.044), and shorter length of stay (P = 0.044). Thigh pain VAS score at 1 month after surgery was significantly greater in the tourniquet group (P < 0.001), as was knee pain during activity and at rest on PODs 2–3 (all P < 0.05). The tourniquet group also showed a significantly higher rate of tension blisters (28.8% vs. 7.1%, P = 0.038).

Conclusions

Tourniquet use during robot-assisted TKA does not reduce total blood loss, and it appears to increase postoperative pain, aggravate muscle injury, and prolong postoperative recovery.

Trial registration ChiCTR, ChiCTR2100041800. Registered 5 January 2021, http://www.chictr.org.cn/index.aspx.

Robot-assisted total knee arthroplasty is associated with a learning curve for surgical time but not for component alignment, limb alignment and gap balancing

PURPOSE

The application of robotics in the operating theatre for total knee arthroplasty (TKA) remains controversial. As with all new technology, the introduction of new systems is associated with a learning curve and potentially associated with extra complications. Therefore, the aim of this study is to identify and predict the learning curve of robot-assisted (RA) TKA.

METHODS

A RA TKA system (MAKO) was introduced in April 2018 in our service. A retrospective analysis was performed of all patients receiving a TKA with this system by six surgeons. Operative times, implant and limb alignment, intraoperative joint balance and robot-related complications were evaluated. Cumulative summation (CUSUM) analyses were used to assess learning curves for operative time, implant alignment and joint balance in RA TKA. Linear regression was performed to predict the learning curve of each surgeon.

RESULTS

RA TKA was associated with a learning curve of 11-43 cases for operative time (p < 0.001). This learning curve was significantly affected by the surgical profile (high vs. medium vs. low volume). A complete normalisation of operative times was seen in four out of five surgeons. The precision of implant positioning and gap balancing showed no learning curve. An average deviation of 0.2° (SD 1.4), 0.7° (SD 1.1), 1.2 (SD 2.1), 0.2° (SD 2.9) and 0.3 (SD 2.4) for the mLDFA, MPTA, HKA, PDFA and PPTA from the preoperative plan was observed. Limb alignment showed a mean deviation of 1.2° (SD 2.1) towards valgus postoperatively compared to the intraoperative plan. One tibial stress fracture was seen as a complication due to suboptimal positioning of the registration pins.

CONCLUSION

RA TKA is associated with a learning curve for surgical time, which might be longer than reported in current literature and dependent on the profile of the surgeon. There is no learning curve for component alignment, limb alignment and gap balancing.

LEVEL OF EVIDENCE

IV.

No difference in PROMs between robotic-assisted CR versus PS total knee arthroplasty: a preliminary study

The purpose of this study was to determine if significant clinical differences exist in patient-reported outcome measures (PROMs) between PS and CR TKAs implanted using robotic-assisted technology. This was an IRB-approved retrospective study from an institutional database evaluating 214 knees in 190 patients. Inclusion criteria included: primary RA-TKA, age 22-89 at the time of surgery, preoperative coronal limb deformity within 15º of neutral alignment, and minimum 1-year follow-up. The PS cohort consisted of 103 patients with 107 RA-TKAs, whereas the CR cohort consisted of 87 patients with 107 RA-TKAs. Cohorts were compared on the basis of demographics and PROMs (KSS knee, KSS function, FJS-12, KOOS-JR, WOMAC, and 5-point satisfaction Likert scale) collected preoperatively and at 1-year follow-up. Statistical analyses comparing measures were conducted via Student's t tests for continuous data and Chi-squared analyses for categorical data. There were no significant differences identified in short-term PROMs at 1-year follow-up between cohorts (all p values > 0.05). 93.1% of patients with CR knees and 94.7% of patients with PS knees reported a satisfaction level of "very satisfied" or "satisfied". Revision arthroplasty occurred in six knees (2.8%, 3 knees in CR cohort, 3 knees in PS cohort) with no differences in overall complications between groups. The use of RA-TKA technology promoted high patient satisfaction scores within this study, independent of CR or PS implant type with no significant differences in PROMs, satisfaction, revisions, or complications between the two groups.

Health economic value of CT scan based robotic assisted UKA: a systematic review of comparative studies

PURPOSE

The aim of this systematic review was to compare relevant health economic consequences of the CT-based robotic-arm-assisted system versus conventional Uni-compartmental Knee Arthroplasty (UKA).

METHODS

In November 2020, A PRISMA systematic review was conducted using four databases (Pubmed, Scopus, Cochrane and Google Scholar) to identify all comparative studies reporting health economic assessments, such as robotic system costs, consumable costs, surgical revision rate, operating time, length of stay, and inpatient care costs.

RESULTS

A total of nine comparative studies published between 2014 and 2020 were included in this systematic review. There was a moderate risk of bias as assessed using the ROBINS-I Tool. The CT-based robotic-arm-assisted system seemed to be associated with a lower risk of revision, decreased analgesia requirements during hospitalization, a shorter length of stay, and lower inpatient care costs compared to a conventional technique.

CONCLUSION

CT-based robotic-arm-assisted system for UKA appears to be an economically viable solution with a positive health economic impact as it tends to decrease revision rate compared to conventional UKA, improve post-operative rehabilitation and analgesia management. Post-operative inpatient care costs seem lower with the robotic-assisted system but depend on institutional case volume and differ among health systems. More studies are needed to confirm cost-effectiveness of CT-based robotic-arm-assisted system based on different health systems.

LEVEL OF EVIDENCE

Systematic review, Level IV.

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

INTRODUCTION

A review of the data supporting robotic systems currently available is presented focussing on precision and reproducibility, radiological outcomes, clinical outcomes, and survivorship.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Robotics in orthopaedic surgery: why, what and how?

INTRODUCTION

Robotics applied to orthopedics has become an interesting topic both from the surgical point of view and the engineering one. The main goal of those systems is the enhancement of joint arthroplasty surgery, providing the robotic support to precisely and accurately prepare the bone, restore the limb alignment and the physiological kinematics of the joint. Various robotic systems are currently available on the market, each addressing specific kind of surgeries and characterized by a series of specific features that may involve different requirements and/or modus operandi.

MATERIAL AND METHODS

An overview of these devices was performed, addressing the different categories in which robots are subdivided in terms of: operations performed, requirements and level of interaction of the surgeon. The main models currently available on the market were addressed and relative studies in the literature were reported and compared, to highlight the benefits and drawbacks of the different technologies.

RESULTS

The different robotic systems were subdivided in: open/closed platform, image-based/imageless and active/passive/semi-active. Regardless of the typology of robotic system, the main aim is to improve precision and accuracy of the operation. It is to be noted that, regardless of the typology of robotic system, the surgeon is still in charge of the planning and approval of the operation: only the precise and consistent execution of his directives is entrusted to the robot. The positive factors have however to be weighed against the fact that robotic systems involve an important initial investment and most of the times require the surgeons and the staff to learn how to operate them (with a learning curve differing from system to system).

CONCLUSIONS

Each surgeon, when considering if and which robotic system to adopt, has to properly evaluate the different benefits and drawbacks involved to find the surgical robot that fits his needs the best.

Active robotic technologies for total knee arthroplasty

INTRODUCTION

When active robotic technologies for Total Knee Arthroplasty (TKA) were introduced over 20 years ago, broad usage of robotic technology was not felt to be needed as early data suggested no clear improvement in clinical outcomes compared to conventional techniques of implantation. Only recently has there been renewed enthusiasm for use of robotic technologies for implantation.

MATERIALS AND METHODS

Active robotic technology specifically refers to the use of a robot for planning and executing the surgical procedure-with surgeon guidance and control. The physical work of bone preparation is performed by a milling tool, following a cut path defined by a CT-based preoperative plan. This manuscript describes the IDE experience of the only active robotic system (ARoS) available in the US, which took place from February 2017 through December 2018.

RESULTS

115 patients were enrolled in an IDE study to evaluate the safety and efficacy of an ARoS for TKA. No previously described safety issues for TKA occurred. Three-dimensional accuracy of component placement used the preoperative CT plan compared to the 3-months postoperative CT scan to demonstrate accuracy of all autonomous resections to within 1.5 mm and/or 1.5 degrees. Surgical planning and execution to restore alignment along kinematic principles were used in 40 procedures and to achieve mechanical alignment in 75 procedures.

CONCLUSIONS

This FDA study of an active robotic approach for TKA represented the first multicenter trial and first US experience with this technology. Results demonstrated an excellent safety profile and high degree of accuracy. Advantages of this approach relate to standardization of the technique, multiple device options in the implant library, an excellent safety and accuracy profile, and consistency of results. Active robotics for TKA represents a viable and safe technique for primary TKA.

Optimal designs and surgical technique for hip and knee joint replacement: The best is yet to come!

Over the last three decades, there have been significant advancements in knee and hip replacement technology. The implants and the surgical technology we now have to aid in their implantation are advancing and improving functional outcomes and survivorship. Despite these advancements, there are still issues with patient satisfaction, functional limitations, and early revisions due to instability and aseptic loosening. This article reviews the state of current technology in hip and knee replacement implant design and surgical technique, and reviews some of the current implant designs and surgical technologies that may be able to solve some of the most common issues in the knee and hip replacement surgery.

Robot-Assisted versus Conventional Total and Unicompartmental Knee Arthroplasty: A Meta-analysis of Radiological and Functional Outcomes

The study aims to provide an up-to-date systematic review and meta-analysis comparing radiological and functional outcomes of total knee arthroplasty (TKA) and unicompartmental knee arthroplasty (UKA) using either robotic assistance or conventional methods from the latest assemblage of evidence. This study was conducted according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and MOOSE (Meta-analysis of Observational Studies in Epidemiology) guidelines. All studies in PubMed, EMBASE, Medline, and Cochrane that reported radiological and functional outcomes after TKA or UKA with either robotic or conventional methods were included in the review. Selected endpoints for random effects, pairwise meta-analysis included operative details, radiological outcomes (mechanical axis, component angle deviation, and outliers), and functional outcomes (American Knee Society Score, Knee Society Function Score, revision and complication rate, range of motion (ROM), Hospital for Special Surgery score, and Western Ontario and McMaster Universities Osteoarthritis Index). A total of 23 studies comprising 2,765 knees were included from the initial search. Robot-assisted TKA and UKA were associated with significantly better component angle alignment accuracy (low-to-high quality evidence) at the cost of significantly greater operation time. Robot-assisted UKA was found to have significantly better short-term functional outcomes compared with conventional UKA (moderate-to-high quality evidence). Robot-assisted TKA, however, did not exhibit significantly better short- and midterm subjective knee outcome scores compared with its conventional counterpart (high-quality evidence). Robot-assisted TKA and UKA were associated with nonstatistically significant improved ROM and lesser rates of revision. Robot-assisted total and unicompartmental knee arthroplasty leads to better radiological outcomes, with no significant differences in mid- and long-term functional outcomes compared with conventional methods for the former. Larger prospective studies with mid- and long-term outcomes are required to further substantiate findings from the present study.

[Application and research progress of robotic-arm in total knee arthroplasty]

OBJECTIVE

To summarize the application and research progress of robotic-arm in total knee arthroplasty (TKA).

METHODS

Relevant literature at home and abroad was extensively reviewed to analyze the advantages and disadvantages of robotic-arm assisted TKA (RATKA).

RESULTS

Accurate reconstruction of lower extremity alignment and rotation alignment, accurate osteotomy and implant prosthesis in TKA are very important to improve the effectiveness and prolong the life of the prosthesis. Traditional TKA deviations occur in key links such as osteotomy due to operator's operation. RATKA solves the above problems to a certain extent and can assist accurate osteotomy and implant prosthesis, and protect the soft tissues around the knee joint. Patients' satisfaction after RATKA is high, and the operator's learning curve is shorter, which improves the efficiency of the operation. But it also has disadvantages such as prolonged operation time, increased complications and medical costs.

CONCLUSION

Preliminary clinical application studies have shown that RATKA has satisfactory effectiveness, but its definite advantages compared with traditional TKA need to be confirmed by a large number of randomized controlled trials and long-term follow-up.

The current state of robotics in total knee arthroplasty

Robotic total knee arthroplasty (TKA) has demonstrated improved component positioning and a reduction of alignment outliers with regard to pre-operative planning.

Early robotic TKA technologies were mainly active systems associated with significant technical and surgical complications.

Current robotic TKA systems are predominantly semi-active with additional haptic feedback which minimizes iatrogenic soft tissue injury compared to conventional arthroplasty and older systems.

Semi-active systems demonstrate advantages in terms of early functional recovery and hospital discharge compared to conventional arthroplasty.

Limitations with current robotic technology include high upfront costs, learning curves and lack of long-term outcomes.

The short-term gains and greater technical reliability associated with current systems may justify the ongoing investment in robotic technology.

Further long-term data are required to fully ascertain the cost-effectiveness of newer robotic systems.

Cite this article: EFORT Open Rev 2021;6:270-279. DOI: 10.1302/2058-5241.6.200052

A clinical review of robotic navigation in total knee arthroplasty: historical systems to modern design

Robotic-assisted total knee arthroplasty (RA-TKA) has shown improved reproducibility and precision in mechanical alignment restoration, with improvement in early functional outcomes and 90-day episode of care cost savings compared to conventional TKA in some studies. However, its value is still to be determined.Current studies of RA-TKA systems are limited by short-term follow-up and significant heterogeneity of the available systems.In today's paradigm shift towards an increased emphasis on quality of care while curtailing costs, providing value-based care is the primary goal for healthcare systems and clinicians. As robotic technology continues to develop, longer-term studies evaluating implant survivorship and complications will determine whether the initial capital is offset by improved outcomes.Future studies will have to determine the value of RA-TKA based on longer-term survivorships, patient-reported outcome measures, functional outcomes, and patient satisfaction measures. Cite this article: EFORT Open Rev 2021;6:252-269. DOI: 10.1302/2058-5241.6.200071.

Can robot-assisted total knee arthroplasty be a cost-effective procedure? A Markov decision analysis

BACKGROUND

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.

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.

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% 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 253 cases per robot per year is needed to prove cost-effective taking the predetermined parameter values into account.

CONCLUSION

Based upon transitional probabilities and independent variables derived from existing studies, RA TKA may be cost-effective at a surgical volume of 253 cases per robot per year when compared to conventional TKA.

A brief history of artificial intelligence and robotic surgery in orthopedics & traumatology and future expectations

Recently, the rate of the production and renewal of information makes it almost impossible to be updated. It is quite difficult to process and interpret large amounts of data by human beings. Unlimited memory capacities, learning abilities, artificial intelligence (AI) applications, and robotic surgery techniques cause orthopedic surgeons to be concerned about losing their jobs. The idea of AI, which was first introduced in 1956, has evolved over time by revealing deep learning and evolutionary plexus that can mimic the human neuron cell. Image processing is the leading improvement in developed algorithms. Theoretically, these algorithms appear to be quite successful in interpreting medical images and orthopedic decision support systems for preoperative evaluation. Robotic surgeons have emerged as significant competitors in carrying out the taken decisions. The first robotic applications of orthopedic surgery started in 1992 with the ROBODOC system. Applications started with hip arthroplasty continued with knee arthroplasty. Publications indicate that problems such as blood loss and infection caused by the long operation time in the early stages have been overcome in time with the help of learning systems. Comparative studies conducted with humans indicate that robots are better than humans in providing limb lengthening, patient satisfaction, and cost. As in all new technologies, the developments in both AI applications and robotics surgery indicate that technology is in favor in terms of cost/benefit analyses. Although studies indicate that new technologies are more successful than humans, the replacement of technology with experience and long-term results with traditional methods will not be observed in the near future.

Robotic total knee arthroplasty: A missed opportunity for cost savings in Bundled Payment for Care Improvement initiatives?

BACKGROUND

The use of robotic total knee arthroplasty has become increasingly prevalent. Proponents of robotic total knee arthroplasty tout its potential to not only improve outcomes, but also to reduce costs compared with traditional total knee arthroplasty. Despite its potential to deliver on the value proposition, whether robotic total knee arthroplasty has led to improved outcomes and cost savings within Medicare's Bundled Payment for Care Improvement initiative remains unexplored.

METHODS

Medicare beneficiaries who underwent total knee arthroplasty designated under Medicare severity diagnosis related group 469 or 470 in the year 2017 were identified using the 100% Medicare Inpatient Standard Analytic Files. Hospitals participating in the Bundled Payment for Care Improvement were identified using the Bundled Payment for Care Improvement analytic file. We calculated risk-adjusted, price-standardized payments for the surgical episode from admission through 90-days postdischarge. Outcomes, utilization, and spending were assessed relative to variation between robotic and traditional total knee arthroplasty.

RESULTS

Overall, 198,371 patients underwent total knee arthroplasty (traditional total knee arthroplasty: n= 194,020, 97.8% versus robotic total knee arthroplasty: n = 4,351, 2.2%). Among the 3,272 hospitals that performed total knee arthroplasty, only 300 (9.3%) performed robotic total knee arthroplasty. Among the 183 participating in the Bundled Payment for Care Improvement, only 40 (19%) hospitals performed robotic total knee arthroplasty. Risk-adjusted 90-day episode spending was $14,263 (95% confidence interval $14,231-$14,294) among patients who underwent traditional total knee arthroplasty versus $13,676 (95% confidence interval $13,467-$13,885) among patients who had robotic total knee arthroplasty. Patients who underwent robotic total knee arthroplasty had a shorter length of stay (traditional total knee arthroplasty: 2.3 days, 95% confidence interval: 2.3-2.3 versus robotic total knee arthroplasty: 1.9 days, 95% confidence interval: 1.9-2.0), as well as a lower incidence of complications (traditional total knee arthroplasty: 3.3%, 95% confidence interval: 3.2-3.3 versus robotic total knee arthroplasty: 2.7%, 95% confidence interval: 2.3-3.1). Of note, patients who underwent robotic total knee arthroplasty were less often discharged to a postacute care facility than patients who underwent traditional total knee arthroplasty (traditional total knee arthroplasty: 32.4%, 95% confidence interval: 32.3-32.5 versus robotic total knee arthroplasty: 16.8%, 95% confidence interval 16.1-17.6). Both Bundled Payment for Care Improvement and non-Bundled Payment for Care Improvement hospitals with greater than 50% robotic total knee arthroplasty utilization had lower spending per episode of care versus spending at hospitals with less than 50% robotic total knee arthroplasty utilization.

CONCLUSION

Overall 90-day episode spending for robotic total knee arthroplasty was lower than traditional total knee arthroplasty (Δ $-587, 95% confidence interval: $-798 to $-375). The decrease in spending was attributable to shorter length of stay, fewer complications, as well as lower utilization of postacute care facility. The cost savings associated with robotic total knee arthroplasty was only realized when robotic total knee arthroplasty volume surpassed 50% of all total knee arthroplasty volume. Hospitals participating in the Bundled Payment for Care Improvement may experience cost-saving with increased utilization of robotic total knee arthroplasty.

Total knee arthroplasty: Latest robotics implantation techniques

The recent introduction of new robotic systems for total knee arthroplasty (TKA) has created somewhat of a craze. Nevertheless, we can ask ourselves whether it is justified to use these new but very costly technologies. The results and limitations of these robotic tools must be analyzed systematically before confirming their benefits. Most of the newest robotic systems are interactive ones. These systems can accurately restore the mechanical axis and can improve the ligament balance and implant positioning. Theoretically, this can lead to better survival, function and outcomes. Recent studies have shown that use of robotics for TKA implantation does not increase the surgery time and does not cause more complications. Nevertheless, the long-term advantages of robotics use in this context remains to be proven. This task will be more difficult since there is currently no consensus as to the ideal positioning of TKA implants for a given patient. The aim of this study is to summarize this topic by answering the following questions: What are the different types of robots that can be used for TKA implantation? Which steps of the TKA surgical procedure are done with robotic arm assistance? What are the outcomes of these new implantation techniques? What are the limitations of these new implantation techniques? LEVEL OF EVIDENCE: V; expert opinion.

A Historical Review of Medical Robotic Platforms

This paper provides a brief history of medical robotic systems. Since the first use of robots in medical procedures, there have been countless companies competing to developed robotic systems in hopes to dominate a field. Many companies have succeeded, and many have failed. This review paper shows the timeline history of some of the old and most successful medical robots and new robotic systems. As the patents of the most successful system, i.e., Da Vinci® Surgical System, have expired or are expiring soon, this paper can provide some insights for new designers and manufacturers to explore new opportunities in this field.