The MAKO robotic-arm knee arthroplasty system

An Advanced Knee Simulator Model Can Reproducibly Be Used for Ligament Balancing Training during Total Knee Arthroplasty

A critical and difficult aspect of total knee arthroplasty (TKA) is ligamentous balancing for which cadavers and models have played a large role in the education and training of new arthroplasty surgeons, although they both have several shortcomings including cost, scarcity, and dissimilarity to in vivo ligament properties. An advanced knee simulator (AKS) model based on computed tomography (CT) scans was developed in the setting of these challenges with cadavers and previous models. In this study, we compared the ligament balancing between AKS and human cadaveric knees to assess the validity of using the AKS for ligament balancing training during TKA. A CT scan of a TKA patient with varus deformity was used to design the AKS model with modular components, using three-dimensional printing. Three fellowship-trained arthroplasty surgeons used technology-assisted TKA procedure to plan and balance three cadaver knees and the AKS model. Medial and lateral laxity data were captured using manual varus and valgus stress assessments for cadavers and the model in an extension pose (10 degrees of flexion from terminal extension) and between 90 and 95 degrees for flexion. After preresection assessments, surgeons planned a balanced cruciate-retaining TKA. Following bony cuts and trialing, extension and flexion ligament laxity values were recorded in a similar manner. Descriptive statistics and Student's t-tests were performed to compare the cadavers and model with a p-value set at 0.05. Preresection medial/lateral laxity data for both extension and flexion were plotted and showed that the highest standard deviation (SD) for the cadavers was 0.67 mm, whereas the highest SD for the AKS was 1.25 mm. A similar plot for trialing demonstrated that the highest SD for the cadavers was 0.6 mm, whereas the highest SD for the AKS was 0.61 mm. The AKS trialing data were highly reproducible when compared with cadaveric data, demonstrating the value of the AKS model as a tool to teach ligament balancing for TKA and for future research endeavors.

Enhancing total knee arthroplasty outcomes: the role of individualized femoral sagittal alignment in robotic-assisted surgery - A randomized controlled trial

BACKGROUND

Optimal sagittal alignment of the femoral prosthesis is critical to the success of total knee arthroplasty (TKA). While robotic-assisted TKA can improve alignment accuracy, the efficacy of default femoral alignment versus individualized alignment remains under scrutiny. This study aimed to compare the differences in prosthetic alignment, anatomical restoration, and clinical outcomes between individualized femoral sagittal alignment and default sagittal alignment in robotic-assisted TKA.

METHODS

In a prospective randomised controlled trial, 113 patients (120 knees) underwent robotic-assisted TKA were divided into two groups: 61 with individualized femoral flexion (individualized alignment group) and 59 with default 3-5° flexion (default alignment group). The individualized alignment was based on the distal femoral sagittal anteverted angle (DFSAA), defined as the angle between the mechanical and distal anatomical axes of the femur. The radiographic and clinical outcomes were compared.

RESULTS

Despite similar postoperative femoral flexion angles between groups (P = 0.748), the individualized alignment group exhibited significantly lower incidences of femoral prosthesis extension and higher rates of optimal 0-3° prosthesis flexion (9.8% vs. 27.1%, P = 0.014,78.7% vs. 55.9%, p = 0.008, respectively). The individualized alignment group also demonstrated more favourable changes in sagittal anatomy, with higher maintenance of postoperative anterior femoral offset within 1 mm (54.1% vs. 33.9%, P = 0.026) and posterior condylar offset within 1 mm and 2 mm (44.3% vs. 25.4%, p = 0.031,73.8% vs. 50.8%, p = 0.010, respectively). Although slight improvement in the Hospital for Special Surgery Knee Score (HSS) at three months was observed (P = 0.045), it did not reach a minimal clinically important difference.

CONCLUSION

Individualized tailoring of femoral sagittal alignment in robotic-assisted total knee arthroplasty (TKA) enhances prosthetic alignment and anatomical restoration, suggesting potential improvements in postoperative outcomes.

Is bicortical femoral pin insertion safe for Image-based Robotic Knee Arthroplasty Surgery ? A comparative complications analysis in 970 Consecutive Cases

OBJECTIVES

Limited data exists on complications associated with robotic image-based system in knee arthroplasty. This study aims to document complications in robotic arm-assisted knee arthroplasties, and evaluate the system's safety by comparing two femoral pin insertion methods: bicortical diaphyseal with additional stab wounds, and unicortical metaphyseal placement through the main incision.

METHODS

All patients undergoing primary knee arthroplasty with the image-based robotic system (Mako, Stryker, Mako Surgical Corp., Fort Lauderdale, FL, USA) from 1st March 2021 to 31st January 2024 with a minimum follow-up of 2 months were included. Demographics, system and non-system-related complications, as well as outcomes were recorded. Complications were categorized as either major (requiring a second surgical intervention) or minor.

RESULTS

A total of 970 consecutive cases (median age 69.3 years) were analyzed. The unicortical group comprised 651 cases, while the bicortical group 319. The incidence of non-system-related complications was 2.37%, with the most common being joint stiffness (10 cases; 1.03%), followed by lateral femoral condyle fracture (4;0.41%). The overall incidence of system-specific complications was 1.03%. Pin-related femoral fractures occurred in 0.2% of cases, all postoperatively and in the unicortical group. There was no statistically significant difference between the femoral pin insertion-related complication rates among the two groups (0.3% in the unicortical, compared to 0% in the bicortical group; p-value= 0.3). Complications included tibia fracture (0.1%), delayed wound healing (0.2%), superficial wound infection (0.1%), tibia osteomyelitis (0.1%), and "exostosis" (0.2%). The major complications rate was 0.3% and minor 0.7%.

CONCLUSIONS

Minimal system-specific overall complications indicate that robotic arm-assisted surgery is safe. The bicortical diaphyseal femoral pin insertion method does not increase the complication rates compared to the unicortical metaphyseal method.

LEVEL OF EVIDENCE

III.

Artificial intelligence: revolutionizing robotic surgery: review

Robotic surgery, known for its minimally invasive techniques and computer-controlled robotic arms, has revolutionized modern medicine by providing improved dexterity, visualization, and tremor reduction compared to traditional methods. The integration of artificial intelligence (AI) into robotic surgery has further advanced surgical precision, efficiency, and accessibility. This paper examines the current landscape of AI-driven robotic surgical systems, detailing their benefits, limitations, and future prospects. Initially, AI applications in robotic surgery focused on automating tasks like suturing and tissue dissection to enhance consistency and reduce surgeon workload. Present AI-driven systems incorporate functionalities such as image recognition, motion control, and haptic feedback, allowing real-time analysis of surgical field images and optimizing instrument movements for surgeons. The advantages of AI integration include enhanced precision, reduced surgeon fatigue, and improved safety. However, challenges such as high development costs, reliance on data quality, and ethical concerns about autonomy and liability hinder widespread adoption. Regulatory hurdles and workflow integration also present obstacles. Future directions for AI integration in robotic surgery include enhancing autonomy, personalizing surgical approaches, and refining surgical training through AI-powered simulations and virtual reality. Overall, AI integration holds promise for advancing surgical care, with potential benefits including improved patient outcomes and increased access to specialized expertise. Addressing challenges and promoting responsible adoption are essential for realizing the full potential of AI-driven robotic surgery.

Robotic-arm-assisted lateral unicompartmental knee arthroplasty leads to high implant survival and patient satisfaction at mean 10-year follow-up

BACKGROUND

There is a lack of literature reporting on long-term outcomes following robotic-arm-assisted lateral unicompartmental knee arthroplasty (UKA). This study assessed the long-term survivorship, patient-reported satisfaction and pain scores following robotic-arm-assisted lateral UKA for lateral compartment osteoarthritis (OA).

METHODS

A single surgeon's database was reviewed to identify all patients who underwent robotic-arm-assisted lateral UKA with a cemented, fixed-bearing prosthesis prior to May 2015. Patients were contacted to determine implant survivorship, satisfaction and pain. Kaplan-Meier models were applied to analyse survival.

RESULTS

A total of 77 knees (70 patients) with a mean follow-up of 10.2 ± 1.5 years (range: 8.1-13.3) were included. Five knees were revised, corresponding to a 10-year survivorship of 96.1% and estimated survival time of 12.7 ± 0.3 years (95% confidence interval: 12.2-13.2) with all-cause revision as the endpoint. Unexplained pain (40.0%) and progression of OA (40.0%) in contralateral compartments were the most reported reasons for revision. Among patients without revision, 94.4% were either satisfied or very satisfied with their lateral UKA and the average pain score was 1.1.

CONCLUSION

Robotic-arm-assisted lateral UKA led to high implant survivorship and patient satisfaction, and low pain scores at long-term follow-up. Progression of OA in contralateral compartments and unexplained pain were the most frequent reasons for revision. These findings support the continued use of robotic-arm-assisted lateral UKA for lateral compartment OA; however, its clinical value over conventional techniques remains to be established in prospective comparative studies.

LEVEL OF EVIDENCE

Therapeutic Level IV.

Variability in Alignment and Bone Resections in Robotically Balanced Total Knee Arthroplasties

Image-based robotic-assisted total knee arthroplasty (RA-TKA) allows three-dimensional surgical planning informed by osseous anatomy, with intraoperative adjustment based on a dynamic assessment of ligament laxity and gap balance. The aim of this study was to identify ranges of implant alignment and bone resections with RA-TKA. We retrospectively reviewed 484 primary RA-TKA cases, stratified by preoperative coronal alignment. Demographics and intraoperative data were collected and compared using Chi-square and ANOVA tests. Planned limb, femoral, and tibial alignment became increasingly varus in a progressive order from valgus to neutral to the highest in varus knees (p < 0.001). Planned external transverse rotation relative to the TEA was lowest in the valgus cohort; relative to the PCA, whereas the varus cohort was highest (p < 0.001, both). Planned resections of the lateral distal femur and of the medial posterior femur were greater in the varus group compared to neutral and valgus (p < 0.001). There were significant differences between cohorts in planned tibia resections, laterally and medially. Varus knees demonstrated higher variability, while valgus and neutral had more metrics with low variability. This study demonstrated trends in intraoperative planned alignment and resection metrics across various preoperative coronal knee alignments. These findings contribute to the understanding of RA-TKA and may inform surgical decision-making.

DEIT-Based Bone Position and Orientation Estimation for Robotic Support in Total Knee Arthroplasty-A Computational Feasibility Study

Total knee arthroplasty (TKA) is a well-established and successful treatment option for patients with end-stage osteoarthritis of the knee, providing high patient satisfaction. Robotic systems have been widely adopted to perform TKA in orthopaedic centres. The exact spatial positions of the femur and tibia are usually determined through pinned trackers, providing the surgeon with an exact illustration of the axis of the lower limb. The drilling of holes required for mounting the trackers creates weak spots, causing adverse events such as bone fracture. In the presented computational feasibility study, time differential electrical impedance tomography is used to locate the femur positions, thereby the difference in conductivity distribution between two distinct states s0 and s1 of the measured object is reconstructed. The overall approach was tested by simulating five different configurations of thigh shape and considered tissue conductivity distributions. For the cylinder models used for verification and reference, the reconstructed position deviated by about ≈1 mm from the actual bone centre. In case of models mimicking a realistic cross section of the femur position deviated between 7.9 mm 24.8 mm. For all models, the bone axis was off by about φ=1.50° from its actual position.

Trochlea morphology demonstrates variability but no gender difference in osteoarthritic patients undergoing total knee arthroplasty

BACKGROUND

In recent years, coronal lower leg alignment has received significant attention. Two classifications recently described the variability in both femoral and tibial morphology, resulting in differing native lower limb alignment. The native trochlea and the variability in morphology has received less attention.

METHODS

This is a prospective cohort study of 200 patients undergoing robotically assisted TKA. Preoperative transverse CT scans were used to determine the posterior condylar axis (PCA), transepicondylar axis (TEA), lateral trochlear inclination (LTI), the sulcus angle (SA) and the anterior trochlear line (ATL). Outliers were defined as values > 1.5 IQR from median value. Trochlea dysplasia was defined as LTI < 12°. Gender differences were compared.

RESULTS

In total, 99 patients were female (49.4%). SA had a median of 137.0° (IQR 12°), ATL 4° (IQR 4), LTI 18° (IQR 7°). Median TEA-PCA was 5° external (IQR 3°). There were 5.0% outliers in SA, 3.0% of outliers in ATL, 3.5% outliers in LTI and 4.5% outliers in the TEA-PCA. Trochlear dysplasia was present in 11.5% of the measurements. There was no difference in any of the angles between the genders.

CONCLUSION

The present study demonstrates no difference in trochlea morphology between the genders, rather a significant number of overall outliers in trochlear morphology. Larger cohorts but also, more investigations, are needed to better understand the trochlear morphology of patients undergoing total knee arthroplasty. The personalized alignment strategies and implants need to account for this variability in the population.

Robotics in Arthroplasty: Historical Progression, Contemporary Applications, and Future Horizons With Artificial Intelligence (AI) Integration

Robotic technology is increasingly utilized in surgical procedures to enhance precision, particularly in tasks demanding delicate maneuvers beyond human capabilities. Robotic orthopedic surgery emerges as a dynamic and compelling technology reshaping the landscape of surgical practice. This aids surgeons in achieving enhanced accuracy and reproducibility, ultimately aiming for improved patient outcomes. As of now, the majority of these systems are in a developed stage and are gradually gaining broader adoption. These systems have to show that they are user-friendly, are successful in clinical settings, and have a good cost-effectiveness ratio before they can be widely adopted in the field of surgery. In this review, we examine the evolution of robotics in orthopedic surgery, assess its current applications, and provide insights into the future trajectory of this technology, particularly in light of advances in artificial intelligence (AI) and machine learning (ML).

The effect of different alignment strategies on trochlear orientation after total knee arthroplasty

PURPOSE

When planning and delivering total knee arthroplasty (TKA), there are multiple coronal alignment strategies such as functional alignment (FA), kinematic alignment (KA), mechanical and adjusted mechanical alignment (MA, aMA). Recent three-dimensional and robotic-assisted surgery (RAS) studies have demonstrated that KA potentially better restores the trochlear anatomy than MA. The purpose of this study was to compare the restoration of the native trochlear orientation in patients undergoing RAS TKA using four different alignment strategies. It was hypothesised that FA would result in the lowest number of outliers.

METHODS

This is a prospective study of 200 patients undergoing RAS-TKA with a single implant. All patients were analysed for MA and KA prebalancing, and 157 patients received aMA and 43 patients FA with intraoperative balancing. Preoperative transverse computed tomography scans were used to determine the posterior condylar axis (PCA), lateral trochlear inclination (LTI) angle, sulcus angle (SA) and anterior trochlear line (ATL) angle. Implant measurements were obtained using a photographic analysis. Intraoperative software data combined with implant data and preoperative measurements were used to calculate the differences. Outliers were defined as ≥3° of alteration. Trochlea dysplasia was defined as LTI < 12°.

RESULTS

Native transepicondylar PCA had a median of 2°, LTI 18°, SA 137°, ATL 4°. LTI outliers were observed in 47%-60% of cases, with KA < FA < aMA < MA. For ATL, the range of outliers was 40.5%-85%, KA < FA < aMA < MA. SA produced 81% of outliers. Of all median angle values, only LTI when using KA was not significantly altered compared to the native knee.

CONCLUSION

There is a significant alteration of trochlear orientation after TKA, regardless of the alignment strategy used. KA produced the lowest, but a substantial, number of outliers. The uniform design of implants causes the surgeon to compromise on balance in flexion versus trochlear position. The clinical relevance of this compromise requires further clinical investigations.

LEVEL OF EVIDENCE

Level II, prospective cohort study.

Robots on the Stage: A Snapshot of the American Robotic Total Knee Arthroplasty Market

» Computer-assisted robots aid orthopaedic surgeons in implant positioning and bony resection. Surgeons selecting a robot for their practice are faced with numerous options. This study aims to make the choice less daunting by reviewing the most commonly used Food and Drug Administration-approved robotic total knee arthroplasty platforms in the American arthroplasty market.» Modern total knee arthroplasty (TKA) robots use computer guidance to create a virtual knee model that serves as the surgeon's canvas for resection planning.» Most available robotic TKA (rTKA) systems are closed semiactive systems that restrict implant use to those of the manufacturer.» Each system has distinct imaging requirements, safety features, resection methods, and operating room footprints that will affect a surgeon's technique and practice.» Robots carry different purchase, maintenance, and equipment costs that will influence patient access across different socioeconomic groups.» Some studies show improved early patient-reported outcomes with rTKA, but long-term studies have yet to show clinical superiority over manual TKA.

A new seven-axis robotic-assisted total hip arthroplasty system improves component positioning: a prospective, randomized, multicenter study

This study compared the radiologic and clinical outcomes of a new seven-axis robotic-assisted total hip arthroplasty (THA) and conventional THA. Hundred and four patients were randomly assigned to two groups-the robotic-assisted THA group (RAS group) and the conventional THA group (CON group). The preoperative and postoperative Harris Hip score (HHS), acetabular inclination, anteversion, femoral offset, and leg length discrepancy (LLD) were compared. During the follow-up, no patients had any complications that could be associated with the use of the robot. The proportion of acetabular cups in the safety zone was significantly higher in the RAS group than that in the CON group. The two groups had significantly different mean absolute difference of inclination and anteversion. There was no significant difference in the postoperative HHSs, changes in HHSs, femoral offset, and lower limb length between the two groups. The seven-axis robotic-assisted THA system is safe and effective, and leads to better acetabulum cup positioning compared to conventional THA. The improvements observed in the HHS, LLD, and femoral offset in the RAS group were similar to those in the CON group.Clinical trial registration time: 19/05/2022.Clinical trial registration number: ChiCTR2200060115.

Robotic Total Knee Arthroplasty: An Update

Total knee arthroplasty (TKA) is a gold standard surgical procedure to improve pain and restore function in patients affected by moderate-to-severe severe gonarthrosis refractory to conservative treatments. Indeed, millions of these procedures are conducted yearly worldwide, with their number expected to increase in an ageing and more demanding population. Despite the progress that has been made in optimizing surgical techniques, prosthetic designs, and durability, up to 20% of patients are dissatisfied by the procedure or still report knee pain. From this perspective, the introduction of robotic TKA (R-TKA) in the late 1990s represented a valuable instrument in performing more accurate bone cuts and improving clinical outcomes. On the other hand, prolonged operative time, increased complications, and high costs of the devices slow down the diffusion of R-TKA. The advent of newer technological devices, including those using navigation systems, has made robotic surgery in the operatory room more common since the last decade. At present, many different robots are available, representing promising solutions to avoid persistent knee pain after TKA. We hereby describe their functionality, analyze potential benefits, and hint at future perspectives in this promising field.

Real-time active constraint generation and enforcement for surgical tools using 3D detection and localisation network

Introduction: Collaborative robots, designed to work alongside humans for manipulating end-effectors, greatly benefit from the implementation of active constraints. This process comprises the definition of a boundary, followed by the enforcement of some control algorithm when the robot tooltip interacts with the generated boundary. Contact with the constraint boundary is communicated to the human operator through various potential forms of feedback. In fields like surgical robotics, where patient safety is paramount, implementing active constraints can prevent the robot from interacting with portions of the patient anatomy that shouldn't be operated on. Despite improvements in orthopaedic surgical robots, however, there exists a gap between bulky systems with haptic feedback capabilities and miniaturised systems that only allow for boundary control, where interaction with the active constraint boundary interrupts robot functions. Generally, active constraint generation relies on optical tracking systems and preoperative imaging techniques. Methods: This paper presents a refined version of the Signature Robot, a three degrees-of-freedom, hands-on collaborative system for orthopaedic surgery. Additionally, it presents a method for generating and enforcing active constraints "on-the-fly" using our previously introduced monocular, RGB, camera-based network, SimPS-Net. The network was deployed in real-time for the purpose of boundary definition. This boundary was subsequently used for constraint enforcement testing. The robot was utilised to test two different active constraints: a safe region and a restricted region. Results: The network success rate, defined as the ratio of correct over total object localisation results, was calculated to be 54.7% ± 5.2%. In the safe region case, haptic feedback resisted tooltip manipulation beyond the active constraint boundary, with a mean distance from the boundary of 2.70 mm ± 0.37 mm and a mean exit duration of 0.76 s ± 0.11 s. For the restricted-zone constraint, the operator was successfully prevented from penetrating the boundary in 100% of attempts. Discussion: This paper showcases the viability of the proposed robotic platform and presents promising results of a versatile constraint generation and enforcement pipeline.

The LANCET robotic system can improve surgical efficiency in total hip arthroplasty: A prospective randomized, multicenter, parallel-controlled clinical trial

Objective

To evaluate the accuracy and safety of the LANCET robotic system, a robot arm assisted operation system for total hip arthroplasty via a multicenter clinical randomized controlled trial.

Methods

A total of 116 patients were randomized into two groups: LANCET robotic arm assisted THA group (N = 58) and the conventional THA group (N = 58). General information about the patients was collected preoperatively. Operational time and bleeding were recorded during the surgery. The position of the acetabular prosthesis was evaluated by radiographs one week after surgery and compared with preoperative planning. Harris score, hip mobility, prosthesis position and angle and complications were compared between the two groups at three months postoperatively.

Results

None of the 111 patients who ultimately completed the 3-month follow-up experienced adverse events such as hip dislocation and infection during follow-up. In the RAA group, 52 (92.9 %) patients were located in the Lewinnek safe zone and 49 (87.5 %) patients were located in the Callanan safe zone. In the control group were 47 (85.5 %) and 44 (80.0 %) patients, respectively. In the RAA group, 53 (94.6 %) patients had a postoperative acetabular inclination angle and 51 (91.1 %) patients had an acetabular version angle within a deviation of 5° from the preoperative plan. These numbers were significantly higher than those of the control group, which consisted of 42 (76.4 %) and 34 (61.8 %) patients respectively. There were no significant differences between the two groups of subjects in terms of general condition, intraoperative bleeding, hip mobility, and adverse complications.

Conclusion

The results of this prospective randomized, multicenter, parallel-controlled clinical study demonstrated that the LANCET robotic system leads conventional THA surgery in accuracy of acetabular cup placement and does not differ from conventional THA surgery in terms of postoperative hip functional recovery and complications.

The translational potential of this article

In the past, the success rate of total hip arthroplasty (THA) relied heavily on the surgeon's experience. As a result, junior doctors needed extensive training to become proficient in this technique. However, the introduction of surgical robots has significantly improved this situation. By utilizing robotic assistance, both junior and senior doctors can perform THA quickly and efficiently. This advancement is crucial for the widespread adoption of THA, as patients can now receive surgical treatment in local facilities instead of overwhelming larger hospitals and straining medical resources. Moreover, the development of surgical robots with fully independent intellectual property rights holds immense value in overcoming the limitations of high-end medical equipment. This aligns with the objectives outlined in the 14th Five Year Plan for National Science and Technology Strategy.

Pitfalls with the MAKO Robotic-Arm-Assisted Total Knee Arthroplasty

Robotic-arm-assisted total knee arthroplasty (RATKA) with the MAKO system minimizes deviations in implant alignment and yields superior precision in implant position compared to a manual total knee arthroplasty. In this comprehensive commentary, we present and categorize the limitations and pitfalls of the procedure and we also provide recommendations for avoiding each limitation. The main surgeon-related limitations include prolonged operation duration, loose insertion of the checkpoints and pins, wrong registration and mapping, and damage to soft tissues during bone cutting. The system-related issues include the interruptions of the saw-cutting due to vibrations, specifications for the operating room floor and power supply, the high cost of the system, as well as the cost of each operation due to the extra implants, inability to use the system with various prostheses, wireless connection interruptions between the system's components, and hardware issues with the six joints of the robotic device. In order to circumvent the potential challenges in this surgical procedure, it is essential to possess sufficient experience and undergo comprehensive training. Maintaining continuous awareness of the additional implants throughout the entire operation and prioritizing the preservation of soft tissues are of paramount significance. A profound comprehension of the system and its inherent constraints can also prove to be pivotal in certain situations.

Robotic-assisted total knee arthroplasty improves implant position and early functional recovery for the knee with severe varus/valgus deformity

PURPOSE

Robotic-assisted total knee arthroplasty (r-TKA) facilitates precise bone resection and lower limb alignment, yet accuracy and functional recovery for severe varus/valgus deformity is not well-documented. The aim of study was to investigate whether r-TKA improves implant alignment in the coronal and sagittal view and early functional recovery compared to conventional TKA(c-TKA).

METHODS

This comparative study included 86 patients with symptomatic knee arthritis who underwent primary TKA at our institution between 1st May and 31th November 2021. Radiological parameters evaluated included hip-knee-ankle angle (HKAA), femoral varus-valgus angle (FVVA), tibial varus-valgus angle (TVVA), posterior tibial slope angle (PTSA), femoral sagittal angle (FSA), posterior condylar offset ratio, and Insall-Salvati index. Operative time, stay length, and complications were reviewed from patient records. The hospital for special surgery (HSS), Visual Analogue Scale (VAS) and knee joint motion range were evaluated at the six-month follow-up.

RESULTS

The c-TKA and r-TKA groups had no significant differences in HKAA (179.73 ± 3.76°, range: 172.10-188.90° vs. 180.53 ± 2.91°, range: 173.30-188.32°, p = 0.277), FVVA (96.13 ± 2.61°, range: 90.27-101.52° vs. 96.38 ± 2.23°, range: 90.98-100.95°, p = 0.636), and TVVA (88.74 ± 2.03°, range: 83.75-92.74° vs. 89.43 ± 1.83°, range: 85.32-94.15°, p = 1.000). Outlier of mechanical alignment incidence (> 3°) was significantly lower in r-TKA compared with c-TKA, 17.50% (7/40) vs. 41.30% (19/46), (p = 0.017). PTSA of r-TKA remained significantly lower than c-TKA (p = 0.009) in mild-deformity patients. For severe varus/valgus deformity, r-TKA had a significantly lesser HKAA-outlier incidence (p = 0.025), PTSA-outlier incidence (p = 0.019), and lower PTSA (p < 0.001) compared with c-TKA. The r-TKA functional outcome was better than c-TKA regarding HSS (93.12 ± 1.97, range: 90-95, 95%CI:92.11-94.13 vs. 91.33 ± 2.50, range: 85-95, 95%CI:90.20-92.69, p = 0.036), and VAS (0.24 ± 0.44, range:0-1 vs. 0.72 ± 0.75, range:0-2, p = 0.026), knee joint flexion (118.53° ± 8.06, range: 105-130°, 95%CI:114.39-122.67° vs. 112.22 ± 8.09°, range: 100-130°, 95%CI:108.20-116.24° ,p = 0.027) for severe varus/valgus deformity.

CONCLUSION

r-TKA improved lower-limb coronal alignment, sagittal implant position, and early functional recovery for patients with severe varus/valgus deformity of the knee. r-TKA did not confer substantial advantages over c-TKA in both radiological and clinical outcomes for the mild varus/valgus deformity.

Clinical applications of robotic surgery platforms: a comprehensive review

Robotic surgery has expanded globally across various medical specialties since its inception more than 20 years ago. Accompanying this expansion were significant technological improvements, providing tremendous benefits to patients and allowing the surgeon to perform with more precision and accuracy. This review lists some of the different types of platforms available for use in various clinical applications. We performed a literature review of PubMed and Web of Science databases in May 2023, searching for all available articles describing surgical robotic platforms from January 2000 (the year of the first approved surgical robot, da Vinci® System, by Intuitive Surgical) until May 1st, 2023. All retrieved robotic platforms were then divided according to their clinical application into four distinct groups: soft tissue robotic platforms, orthopedic robotic platforms, neurosurgery and spine platforms, and endoluminal robotic platforms. Robotic surgical technology has undergone a rapid expansion over the last few years. Currently, multiple robotic platforms with specialty-specific applications are entering the market. Many of the fields of surgery are now embracing robotic surgical technology. We review some of the most important systems in clinical practice at this time.

No Benefit of Robotic-Assisted over Computer-Assisted Surgery for Achieving Neutral Coronal Alignment in Total Knee Arthroplasty

The use of robotic-assisted surgery (RAS) in total knee arthroplasty (TKA) is becoming increasingly popular due to better precision, potentially superior outcomes and the ability to achieve alternative alignment strategies. The most commonly used alignment strategy with RAS is a modification of mechanical alignment (MA), labeled adjusted MA (aMA). This strategy allows slight joint line obliquity of the tibial component to achieve superior balancing. In the present study, we compared coronal alignment after TKA using RAS with aMA and computer-assisted surgery (CAS) with MA that has been the standard in the center for more than 10 years. We analyzed a prospectively collected database of patients undergoing TKA in a single center. Lateral distal femoral angle (LDFA) and medial proximal tibial angle (MPTA) were compared for both techniques. In 140 patients, 68 CASs and 72 RASs, we observed no difference in postoperative measurements (median 90 degrees for all, LDFA p = 0.676, MPTA p = 0.947) and no difference in outliers <2 degrees (LDFA p = 0.540, MPTA p = 0.250). The present study demonstrates no benefit in eliminating outliers or achieving neutral alignment of both the femoral and the tibial components in robotic-assisted versus computer-assisted TKA if MA is the target. To utilize the precision of RAS, it is recommended to aim for more personalized alignment strategies. The level of evidence is level III retrospective study.

Increased Femoral Component Flexion and No Difference in Slope in Robotic- versus Computer-Assisted Total Knee Arthroplasty When Targeting Mechanical Alignment

Robotic-assisted surgery (RAS) in total knee arthroplasty (TKA) is becoming popular due to better precision, when compared with other instrumentation. Although RAS has been validated in comparison with computer-assisted surgery (CAS), data from clinical settings comparing these two techniques are lacking. This is especially the case for sagittal alignment. Whereas pure mechanical alignment (MA) aims for 0 to 3 degrees of flexion of the femoral component and 3° of posterior slope for the tibial component, adjusted MA (aMA) mostly used with RAS allows for flexing of the femoral component for downsizing and increase of slope for an increase of the flexion gap. In the present study, we compared sagittal alignment after TKA using RAS with aMA and CAS targeting MA, which has been the standard in the center for more than 10 years. We analyzed a prospectively collected database of patients undergoing TKA in a single center. Femoral component flexion and tibial slope were compared for both techniques. In 140 patients, 68 CAS and 72 RAS, we found no difference in tibial slope (p = 0.661), 1° median femoral component flexion (p = 0.023), and no difference in outliers (femur, p = 0.276, tibia, p = 0.289). RAS slightly increases femoral component flexion, but has no influence on tibial slope, when compared with CAS in TKA. If MA is the target, RAS provides no benefit over CAS for achieving the targeted sagittal alignment. LEVEL OF EVIDENCE:  Level III retrospective study.

Artificial intelligence- and computer-assisted navigation for shoulder surgery

Background: Over the last few decades, shoulder surgery has undergone rapid advancements, with ongoing exploration and the development of innovative technological approaches. In the coming years, technologies such as robot-assisted surgeries, virtual reality, artificial intelligence, patient-specific instrumentation, and different innovative perioperative and preoperative planning tools will continue to fuel a revolution in the medical field, thereby pushing it toward new frontiers and unprecedented advancements. In relation to this, shoulder surgery will experience significant breakthroughs. Main body: Recent advancements and technological innovations in the field were comprehensively analyzed. We aimed to provide a detailed overview of the current landscape, emphasizing the roles of technologies. Computer-assisted surgery utilizing robotic- or image-guided technologies is widely adopted in various orthopedic specialties. The most advanced components of computer-assisted surgery are navigation and robotic systems, with functions and applications that are continuously expanding. Surgical navigation requires a visual system that presents real-time positional data on surgical instruments or implants in relation to the target bone, displayed on a computer monitor. There are three primary categories of surgical planning that utilize navigation systems. The initial category involves volumetric images, such as ultrasound echogram, computed tomography, and magnetic resonance images. The second type is based on intraoperative fluoroscopic images, and the third type incorporates kinetic information about joints or morphometric data about the target bones acquired intraoperatively. Conclusion: The rapid integration of artificial intelligence and deep learning into the medical domain has a significant and transformative influence. Numerous studies utilizing deep learning-based diagnostics in orthopedics have remarkable achievements and performance.

Revolutionizing orthopedics: a comprehensive review of robot-assisted surgery, clinical outcomes, and the future of patient care

Robotic-assisted orthopedic surgery (RAOS) is revolutionizing the field, offering the potential for increased accuracy and precision and improved patient outcomes. This comprehensive review explores the historical perspective, current robotic systems, advantages and limitations, clinical outcomes, patient satisfaction, future developments, and innovation in RAOS. Based on systematic reviews, meta-analyses, and recent studies, this article highlights the most significant findings and compares RAOS to conventional techniques. As robotic-assisted surgery continues to evolve, clinicians and researchers must stay informed and adapt their practices to provide optimal patient care. Evidence from published studies corroborates these claims, highlighting superior component positioning, decreased incidence of complications, and heightened patient satisfaction. However, challenges such as costs, learning curves, and technical issues must be resolved to fully capitalize on these advantages.

Beyond the Scalpel: A Tapestry of Surgical Safety, Precision, and Patient Prosperity

In modern surgical practice, the focus extends beyond simply making and closing incisions. We aim to investigate the various complex aspects that redefine the criteria for achieving effective surgical outcomes. This narrative combines current knowledge, integrating practical experiences and academic viewpoints to comprehend the changing field of surgical care thoroughly. The tapestry explores the detailed aspects of surgical safety, examining the most recent progress in protocols, technology, and team dynamics that strive to reduce procedural risks. Examining precision in surgery, this narrative goes beyond conventional limits to explore the incorporation of advanced technologies, such as robotics and navigational systems. The complex interplay between the surgeon's proficiency and these technology aids is crucial in attaining unparalleled accuracy and favorable patient results. The focal point of this investigation is the patient's well-being, encompassing postoperative care, rehabilitation, and long-term health. Actual accounts from surgical procedures highlight the significant influence of comprehensive patient-centered methods, emphasizing the crucial need for empathy, communication, and individualized care plans in promoting healing and adaptability. As we explore this complex situation, the combination of real-life stories and academic discussions creates a clear and detailed image of a surgical environment that goes far beyond the boundaries of the operating room. "Beyond the Scalpel" seeks to engage practitioners, scholars, and stakeholders in a conversation that redefines the criteria for surgical success. It aims to establish a new benchmark that combines safety, precision, and patient well-being, ultimately shaping the future of surgical practice.

Using sequential bone cutting to titrate soft tissue balance in total knee arthroplasty effectively minimizes soft tissue release

BACKGROUND

Achieving soft tissue balance while maintaining limb alignment within acceptable boundaries is crucial for successful total knee arthroplasty (TKA). We proposed a sequential bone cutting (SBC) technique to titrate the soft tissue balance in robot-assisted TKA to achieve the desired balance with minimum soft tissue release.

METHODS

In total, 106 robot-assisted TKAs using the SBC technique were included. The preoperative hip-knee-ankle angle (HKA) was < 10° in 76 and ≥ 10° in 30 knees. The gaps were initially balanced with the help of the pre-resection balancing provided by the robotic system. Soft tissue balance and alignment were quantitatively measured after the initial bone cutting and final bone cutting. Additional adjustments (bone recuts and soft tissue releases) required to address soft tissue imbalance after initial bone cutting were recorded. The frequencies of soft tissue releases, soft tissue balance, and resultant alignment ≤ 3° were compared between non-severe (HKA < 10°) and severe deformity (HKA ≥ 10°) groups.

RESULTS

Soft tissue balance was achieved in 45 knees (42.5%) after initial bone cutting and in 93 knees (87.7%) after final balancing. The postoperative alignment was within 3° from neutral in 87 knees (82.1%) and 3-5° in 17 knees (16.0%). For unbalanced knees (n = 61) after initial bone cutting, soft tissue release was avoided by SBC in 37 knees (60.7%) and was deemed necessary in 24 knees (39.3%). Soft tissue release was more likely to be avoided in the non-severe deformity cohort (86.8% [33 of 38]) than in the severe deformity cohort (17.4% [4 of 23]; p < 0.001). The non-severe deformity cohort showed a significantly higher rate of resultant alignment ≤ 3° from neutral than the severe deformity cohort (90.8% vs. 60.0%; p < 0.001).

CONCLUSION

Pre-resection balancing is inappropriate to ensure soft tissue balance. The SBC technique is effective in minimizing soft tissue release while maintaining overall alignment within acceptable boundaries.

Innovative Approaches to Safe Surgery: A Narrative Synthesis of Best Practices

By encompassing a wide range of best practices within the ever-changing realm of modern surgical care, this exhaustive narrative compendium attempts to unravel the complex tapestry of novel approaches to safe surgery. Within the context of a dynamic surgical environment, this research endeavors to illuminate and integrate state-of-the-art methods that collectively methodically improve patient safety. The narrative elucidates a diverse array of practices that seek to revolutionize the paradigm of safe surgery, emphasizing technological progress, patient-centric approaches, and global viewpoints. The combined effectiveness of these methods in fostering an all-encompassing culture of safety, improving surgical precision, and decreasing complications is revealed by the results obtained from their implementation. The recognition of the dynamic interplay among multiple components, including the active participation of patients, the integration of cutting-edge technologies, and the establishment of comprehensive quality improvement programs, is fundamental to this narrative. By their collective composition, these components support the notion that secure surgical practices are intricate and interrelated. The present synthesis functions as a fundamental resource for healthcare professionals, policymakers, and researchers, providing an enlightening examination of the current condition of secure surgical practices. By emphasizing the promotion of innovation, continuous development, and the utmost quality of patient care, it offers a strategic guide for navigating the complex terrain of safe surgery. In the ever-evolving landscape of surgical care, this narrative synthesis serves as a guiding principle for stakeholders striving to understand better and implement safe surgical procedures in various healthcare environments.

Is robotic assistance more eye-catching than computer navigation in joint arthroplasty? A Google trends analysis from the point of public interest

Computer-assisted navigation system (CAS) and robotic assisted surgery (RAS) have been widely used in joint arthroplasty, but few studies focused on public interest. We aimed to evaluate current trend and seasonality of public interest in CAS and RAS arthroplasty over the past 10 years, and forecast the future development. All data related to CAS or RAS arthroplasty from January 2012 to December 2021 were collected through Google Trends. Public interest was described by relative search volume (RSV). Pre-existing trend was evaluated by linear and exponential models. Time series analysis and ARIMA model were utilized to analyze the seasonality and future trend. R software 3.5.0 was for statistics analysis. Public interest in RAS arthroplasty has been continuously increasing (P < 0.001) and exponential model (R2 = 0.83, MAE = 7.35, MAPE = 34%, RSME = 9.58) fitted better than linear one (R2 = 0.78, MAE = 8.44, MAPE = 42%, RSME = 10.67). CAS arthroplasty showed a downtrend (P < 0.01) with equivalent R2 (0.04) and accuracy measures (MAE = 3.92, MAPE = 31%, RSME = 4.95). The greatest popularity of RAS was observed in July and October, while the lowest was in March and December. For CAS, a rise of public interest was in May and October, but lower values were observed in January and November. Based on ARIMA models, the popularity of RAS might continuously increase and nearly double in 2030, along with a stability with slight downtrend for CAS. Public interest in RAS arthroplasty has been continuously increasing and seems to maintain this uptrend in the next 10 years, whereas popularity of CAS arthroplasty will likely remain stable.

Sub-optimal femoral fit in total knee arthroplasty, a systematic review of human femoral data vs off-the-shelf contemporary femoral components

PURPOSE

The purpose of the current study is to investigate the inadequacy of fit between the human distal femur and the knee implants offerings and describe the available strategies to overcome this issue.

METHODS

A systematic research of the literature was performed to identify studies reporting morphologic measures of the distal femur. Studies were excluded if they included unhealthy knees or the morphological analysis did not report the two key dimensions to identify the patient's unique anatomy: AP length and mediolateral (ML) width. Clinically relevant component overhang or underhang was considered when the metal-bone mismatch was > 3 mm as described in the literature.

RESULTS

Six studies with anthropometric analysis of 1395 distal femurs met the inclusion criteria. The analysis revealed that by employing the available sizes of four current "state-of-the-art" primary off-the shelf (OTS) femoral implants up to 13-41% would show underhang and 9-27% overhang clinically relevant and the introduction of narrower sizes did not reduce this percentage of underhang but improved the overhang rate of 10-15%.

CONCLUSIONS

Whenever an ML/AP mismatch in encountered in the operating room, adaptations are needed, and these bring about deleterious biomechanical and clinical complications. Therefore, this study highlights the need for implants design with multiple ML offerings per AP size, since they provide not only more sizes options but more femoral shapes to match the different ML sizes of the distal femur, compared to designs with single ML offerings for a given femoral AP dimension.

Functional alignment with robotic‑arm assisted total knee arthroplasty demonstrated better patient-reported outcomes than mechanical alignment with manual total knee arthroplasty

PURPOSE

Given the improved accuracy of robot-assisted surgery, robotic-arm assisted functionally aligned total knee arthroplasty (RFA-TKA) aims to preserve the native pre-arthritic knee biomechanics, to achieve balanced flexion-extension gaps. The purpose of this study was to compare the accuracy of the implant position and short-term clinical outcomes of patients who underwent RFA-TKA vs. mechanically aligned total knee arthroplasty with manual technique (MA-TKA).

METHODS

A prospectively collected database was reviewed retrospectively for patients who underwent primary TKA. Sixty patients who underwent RFA-TKA between February 2020 and July 2020 were included in the RFA-TKA group. Sixty patients who underwent MA-TKA were included via 1:1 matching for age, sex, and body mass index based on the RFA-TKA group. For radiological evaluation, knee X-rays were used to assess the functional knee phenotype and implant position accuracy by measuring the coronal and sagittal alignment, and these measurements were compared between the two groups. Patient demographic characteristics and patient-reported outcomes including Knee Society scores, Western Ontario and McMaster Universities Arthritis Index, and forgotten joint score-12 were compared between the groups.

RESULTS

Statistically significant differences were observed in postoperative 2-year clinical outcomes in favor of RFA-TKA group which showed greater accuracy in the tibial component sagittal alignment than MA-TKA (1.0 ± 2.3 vs. 0.7 ± 1.6, respectively; P < 0.001). However, outliers in the component positions were more common in the MA-TKA group, which was statistically significant for the femoral coronal and tibial sagittal alignments (P = 0.017 and 0.015, respectively).

CONCLUSIONS

Functional alignment in TKA could be accurately obtained with the assistance of a robotic arm, and the results showed greater 2 year postoperative patient-reported outcome and satisfaction than mechanically aligned TKA using manual instruments.

LEVEL OF EVIDENCE

III.

Status of robot-assisted artificial total joint arthroplasty in China: a cross-sectional survey of joint surgeons

PURPOSE

The purpose of this study is to report on the use of Robotic-assisted total joint arthroplasty (RA-TJA) in China as well as the experience and expectations of Chinese doctors regarding this technology.

METHOD

A self-administered questionnaire was used to assess the current status of RA-TJA in China, the practical experience and suggestions for improvement of the technology by joint surgeons who have performed RA-TJA, and the interest and expectations of orthopaedic surgeons who have not used RA-TJA. The questionnaire was administered to all the physicians of the Chinese Association of Orthopedic Surgeons (CAOS).

RESULT

A total of 372 qualified questionnaires were generated, among which 28% (n = 104) of the respondents had performed RA-TJA, among those who had performed RA-TJA. When asked how helpful the joint replacement robot was actually/expected to be, there was no significant difference between the expected and actual experience of nonusers and users (p ≥ 0.05); the biggest disadvantage of the current development of RA-TJA was perceived as additional charges to the patient by those who had used it, while those who had not used it perceived it as a limitation of their hospital, both of which were significant differences. Most respondents in both groups (used: 94.2%; not used: 91.4%) were confident in the clinical development of the joint replacement robot.

CONCLUSION

This survey provides cross-sectional data on the current status of Chinese joint surgeons using or not using robots in their daily clinical practice. Improving surgical precision was the consensus of most respondents, while high surgical costs and limitations of hospital conditions were barriers to its development in China.

Comparison of 3D quantitative osteoarthritis imaging biomarkers from paired CT and MR images: data from the IMI-APPROACH study

INTRODUCTION

MRI bone surface area and femoral bone shape (B-score) measures have been employed as quantitative endpoints in DMOAD clinical trials. Computerized Tomography (CT) imaging is more commonly used for 3D visualization of bony anatomy due to its high bone-soft tissue contrast. We aimed to compare CT and MRI assessments of 3D imaging biomarkers.

METHODS

We used baseline and 24-month image data from the IMI-APPROACH 2-year prospective cohort study. Femur and tibia were automatically segmented using active appearance models, a machine-learning method, to measure 3D bone shape, area and 3D joint space width (3DJSW). Linear regression was used to test for correlation between measures. Limits of agreement and bias were tested using Bland-Altman analysis.

RESULTS

CT-MR pairs of the same knee were available from 434 participants (78% female). B-scores from CT and MR were strongly correlated (CCC = 0.967) with minimal bias of 0.1 (SDD = 0.227). Area measures were also correlated but showed a consistent bias (MR smaller). 3DJSW showed different biases (MR larger) in both lateral and medial compartments.

DISCUSSION

The strong correlation and small B-score bias suggests that B-score may be measured reliably using either modality. It is likely that the bone surface identified using MR and CT will be at slightly different positions within the bone/cartilage boundary. The negative bone area bias suggests the MR bone boundary is inside the CT boundary producing smaller areas for MR, consistent with the positive 3DJSW bias. The lateral-medial 3DJSW difference is possibly due to a difference in knee pose during acquisition (extended for CT, flexed for MR).

TRIAL REGISTRATION

NCT03883568.

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

PURPOSE

The 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.

METHODS

Fifty-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).

RESULTS

A 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).

CONCLUSION

The 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 EVIDENCE

III.

Robotic-assisted TKA reduces surgery duration, length of stay and 90-day complication rate of complex TKA to the level of noncomplex TKA

INTRODUCTION

Complex primary total knee arthroplasties (TKA) are reported to be associated with excessive episode of care (EOC) costs as compared to noncomplex procedures. The impact of robotic assistance (rTKA) on economic outcome parameters in greater case complexity has not been described yet. The purpose of this study was to investigate economic outcome parameters in the 90-days postoperative EOC in robotic-assisted complex versus noncomplex procedures.

MATERIALS AND METHODS

This study is a retrospective, single-center review of 341 primary rTKAs performed between 2017 and 2020. Patient collective was stratified into complex (n = 218) and noncomplex TKA (n = 123) based on the presence of the following criteria: Obese BMI, coronal malalignment, flexion contracture > 10°, posttraumatic status, previous correction osteotomy, presence of hardware requiring removal during surgery, severe rheumatoid arthritis. Group comparison included surgery duration, length of stay (LOS), surgical site complications, readmissions, and revision procedures in the 90-days EOC following rTKA.

RESULTS

The mean surgery duration was marginally longer in complex rTKA, but showed no significant difference (75.26 vs. 72.24 min, p = 0.258), neither did the mean LOS, which was 8 days in both groups (p = 0.605). No differences between complex and noncomplex procedures were observed regarding 90-days complication rates (7.34 vs. 4.07%, p = 0.227), readmission rates (3.67 vs. 3.25%, p = 0.841), and revision rates (2.29 vs. 0.81%, p = 0.318).

CONCLUSIONS

Robotic-assisted primary TKA reduces the surgical time, inpatient length of stay as well as 90-days complication and readmission rates of complex TKA to the level of noncomplex TKA. Greater case complexity does not seem to have a negative impact on economic outcome parameters when surgery is performed with robotic assistance.

Kinematic Alignment in Total Knee Arthroplasty Reduces Polyethylene Contact Pressure by Increasing the Contact Area, When Compared to Mechanical Alignment—A Finite Element Analysis

Unrestricted Kinematic alignment (KA) in total knee arthroplasty (TKA) replicates the joint line of each patient by adjusting the cuts based on the anatomy of the patient. Mechanical alignment (MA) aims to restore a neutral mechanical axis of the leg, irrespective of the joint line orientation. The purpose of the present study was to compare contact pressure and contact areas of the polyethylene (PE) bearing surface as well as von Mises stress of the PE-tibial tray interface for MA and KA in the same patient, using CT data and finite element analysis. Finite element models were created from lower leg CT scans of 10 patients with knee osteoarthritis with different phenotypes. Mechanical PE properties were experimentally determined by tensile tests on dumbbell specimens. For numerical simulation purposes an adjusted non-linear material model with the maximum load to failure of 30.5 MPa, was calibrated and utilized. Contact pressure points were the deepest parts of the polyethylene inlay. Contact pressures were either very similar or were increased for MA knees throughout the gait cycle. KA either increased or had a comparable contact area, compared to MA. KA and MA produced comparable von Mises stresses, although both alignments breached the failure point of 30.5 MPa in all 3 valgus knees. This might indicate a higher probability of failure at the inlay-tibial baseplate interface. By maintaining the joint line orientation, KA reduces or has comparable contact pressures on the PE bearing surface by increasing or maintaining the contact area throughout one gait cycle in a validated finite element analysis model in 10 different knee phenotypes. The von Mises stress on the PE-tibial component interface was comparable, except for the valgus knees, where the load to failure was achieved in both alignment strategies and slightly higher stresses were observed for KA. Further studies for different knee phenotypes are needed to better understand the pressure changes depending on the alignment strategy applied.

Bridging 3D Slicer and ROS2 for Image-Guided Robotic Interventions

Developing image-guided robotic systems requires access to flexible, open-source software. For image guidance, the open-source medical imaging platform 3D Slicer is one of the most adopted tools that can be used for research and prototyping. Similarly, for robotics, the open-source middleware suite robot operating system (ROS) is the standard development framework. In the past, there have been several "ad hoc" attempts made to bridge both tools; however, they are all reliant on middleware and custom interfaces. Additionally, none of these attempts have been successful in bridging access to the full suite of tools provided by ROS or 3D Slicer. Therefore, in this paper, we present the SlicerROS2 module, which was designed for the direct use of ROS2 packages and libraries within 3D Slicer. The module was developed to enable real-time visualization of robots, accommodate different robot configurations, and facilitate data transfer in both directions (between ROS and Slicer). We demonstrate the system on multiple robots with different configurations, evaluate the system performance and discuss an image-guided robotic intervention that can be prototyped with this module. This module can serve as a starting point for clinical system development that reduces the need for custom interfaces and time-intensive platform setup.

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.

New Robotic System with Wristed Microinstruments Allows Precise Reconstructive Microsurgery: Preclinical Study

BACKGROUND

Microsurgery allows complex reconstruction of tissue defects after oncological resections or severe trauma. Performing these procedures may be limited by human tremor, precision, and manual dexterity. A new robot designed specifically for microsurgery with wristed microinstruments and motion scaling may reduce human tremor and thus enhance precision. This randomized controlled preclinical trial investigated whether this new robotic system can successfully perform microsurgical needle driving, suturing, and anastomosis.

METHODS

Expert microsurgeons and novices completed six needle passage exercises and performed six anastomoses by hand and six with the new robot. Experienced microsurgeons blindly assessed the quality of the procedures. Precision in microneedle driving and stitch placement was assessed by calculating suturing distances and angulation. Performance of microsurgical anastomoses was assessed by time, learning curves, and the Anastomosis Lapse Index score for objective performance assessment.

RESULTS

Refined precision in suturing was achieved with the robot when compared with the manual technique regarding suture distances (p = 0.02) and angulation (p < 0.01). The time required to perform microsurgical anastomoses was longer with the robot, however, both expert and novice microsurgeons reduced times with practice. The objective evaluation of the anastomoses performed by novices showed better results with the robot.

CONCLUSIONS

This study demonstrated the feasibility of performing precise microsutures and anastomoses using a new robotic system. Compared to standard manual techniques, robotic procedures were longer in time, but showed greater precision.