Robotic alignment system Cirq (Brainlab) for navigated brain tumor biopsies in children.

INTRODUCTION: The Cirq robotic alignment system (Brainlab, Munich, Germany) is a manually adjustable electronic arm with a robotic alignment module on its distal end, enabling the neurosurgeon to automatically and accurately align surgical instruments to a preoperatively planned trajectory. In this study, we share our first experiences and results using Cirq for intracranial tumor biopsy in children. METHODS: From May 2021 until October 2022, all consecutive patients that underwent a brain tumor biopsy using Cirq were included and compared to a historical cohort of patients biopsied with the non-robotic system Varioguide (Brainlab, Munich, Germany). Patient-related data, tumor-related data, and surgery-related data were collected. Registration accuracy was calculated for different patient-to-image registration methods. Pre- and postoperative images were fused, and entry error, target error, and angulation error were calculated. RESULTS: Thirty-seven patients, aged 1-19 years, were included (14 with Cirq and 23 with Varioguide). An integrated histopathological and molecular diagnosis was acquired in all cases. Patient-to-image registration was significantly more accurate when based on bone screw fiducials combined with intraoperative CT, as compared to surface matching or skin fiducials. The target error (Euclidian distance) was 5.3 mm for Cirq as compared to 8.3 mm for Varioguide, but this was not statistically significant. Entry error and angulation error were also not significantly different between both groups. CONCLUSION: Intracranial biopsy with the Cirq robotic system is feasible and safe, and its accuracy does not differ from the Varioguide system.

Stretchable origami robotic arm with omnidirectional bending and twisting.

Inspired by the embodied intelligence observed in octopus arms, we introduce magnetically controlled origami robotic arms based on Kresling patterns for multimodal deformations, including stretching, folding, omnidirectional bending, and twisting. The highly integrated motion of the robotic arms is attributed to inherent features of the reconfigurable Kresling unit, whose controllable bistable deploying/folding and omnidirectional bending are achieved through precise magnetic actuation. We investigate single- and multiple-unit robotic systems, the latter exhibiting higher biomimetic resemblance to octopus' arms. We start from the single Kresling unit to delineate the working mechanism of the magnetic actuation for deploying/folding and bending. The two-unit Kresling assembly demonstrates the basic integrated motion that combines omnidirectional bending with deploying. The four-unit Kresling assembly constitutes a robotic arm with a larger omnidirectional bending angle and stretchability. With the foundation of the basic integrated motion, scalability of Kresling assemblies is demonstrated through distributed magnetic actuation of double-digit number of units, which enables robotic arms with sophisticated motions, such as continuous stretching and contracting, reconfigurable bending, and multiaxis twisting. Such complex motions allow for functions mimicking octopus arms that grasp and manipulate objects. The Kresling robotic arm with noncontact actuation provides a distinctive mechanism for applications that require synergistic robotic motions for navigation, sensing, and interaction with objects in environments with limited or constrained access. Based on small-scale Kresling robotic arms, miniaturized medical devices, such as tubes and catheters, can be developed in conjunction with endoscopy, intubation, and catheterization procedures using functionalities of object manipulation and motion under remote control.

Smart ArM: a customizable and versatile robotic arm prosthesis platform for Cybathlon and research.

BACKGROUND: In the last decade, notable progress in mechatronics paved the way for a new generation of arm prostheses, expanding motor capabilities thanks to their multiple active joints. Yet, the design of control schemes for these advanced devices still poses a challenge, especially with the limited availability of command signals for higher levels of arm impairment. When addressing this challenge, current commercial devices lack versatility and customizing options to be employed as test-beds for developing novel control schemes. As a consequence, researchers resort to using lab-specific experimental apparatuses on which to deploy their innovations, such as virtual reality setups or mock prosthetic devices worn by unimpaired participants. METHODS: To meet this need for a test-bed, we developed the Smart Arm platform, a human-like, multi-articulated robotic arm that can be worn as a trans-humeral arm prosthesis. The design process followed three principles: provide a reprogrammable embedded system allowing in-depth customization of control schemes, favor easy-to-buy parts rather than custom-made components, and guarantee compatibility with industrial standards in prosthetics. RESULTS: The Smart ArM platform includes motorized elbow and wrist joints while being compatible with commercial prosthetic hands. Its software and electronic architecture can be easily adapted to build devices with a wide variety of sensors and actuators. This platform was employed in several experiments studying arm prosthesis control and sensory feedback. We also report our participation in Cybathlon, where our pilot with forearm agenesia successfully drives the Smart Arm prosthesis to perform activities of daily living requiring both strength and dexterity. CONCLUSION: These application scenarios illustrate the versatility and adaptability of the proposed platform, for research purposes as well as outside the lab. The Smart Arm platform offers a test-bed for experimenting with prosthetic control laws and command signals, suitable for running tests in lifelike settings where impaired participants wear it as a prosthetic device. In this way, we aim at bridging a critical gap in the field of upper limb prosthetics: the need for realistic, ecological test conditions to assess the actual benefit of a technological innovation for the end-users.

Effect of tibia-first, restricted functional alignment technique on gap width changes, and component positioning in robotic arm-assisted total knee arthroplasty.

PURPOSE: This study aims to quantitatively assess the predictability of post-resection gap dimensions and the attainment of balanced gaps using robotic arm-assisted total knee arthroplasty (TKA). METHODS: This retrospective cohort study included 100 consecutive patients who underwent robotic arm-assisted TKA for knee osteoarthritis using a restricted functional alignment (FA) technique. Tibial cuts were performed based on preoperative tibial anatomy within predefined boundaries, followed by femoral component adjustments according to tensioned soft tissues to optimise gap balance. The primary outcome was the proportion of balanced gaps, defined as differential laxities of ≤2 mm, across extension, flexion, lateral, and medial gap measurements. Ligament balancing in lateral and medial compartments was assessed using a robotic system at 10° and 90° flexion to evaluate if restricted FA facilitated a balanced knee. Secondary outcomes included implant alignment, resection depth, and patient-reported outcome measures (PROMs). RESULTS: Significant increases in both lateral and medial gaps at 10° and 90° flexion were observed following tibial and femoral bone resections (p < 0.001). At extension, average gap changes were 0.9 mm (lateral) and 1.6 mm (medial) after tibial cuts, and 0.5 mm (lateral) and 1.2 mm (medial) after femoral cuts. At 90° flexion, changes were 0.3 mm (lateral) and 1.7 mm (medial) following tibial cuts, and 1.0 mm (lateral) and 1.4 mm (medial) after femoral cuts. Despite these variations, the tibia-first, gap-balancing technique achieved overall balance in 98% of gap measurements. The tibial component was placed at an average of 2.1° varus, while the femoral component was positioned at 0.3° varus and 1.3° external rotation relative to the surgical transepicondylar axis. Significant improvements in PROMs were noted between preoperative and one-year postoperative evaluations (all p < 0.05). CONCLUSIONS: The tibia-first, restricted FA technique achieved a well-balanced knee in 98% of cases, despite inconsistent gap increments observed between initial assessments and post-resection. LEVEL OF EVIDENCE: Therapeutic Level IV.

Small deviations between planned and performed bone cuts using a CT-based robotic-arm-assisted total knee arthroplasty system.

PURPOSE: Computed tomography (CT)-based robotic system for total knee arthroplasty (TKA) has shown improved accuracy compared to conventional. This study was designed to (1) confirm the accuracy of the robotic system in achieving the plan and (2) establish the alignment and positioning deviation between final components and planning, by measuring the discrepancy between final implant alignment and the corresponding planned cut. METHODS: Ninety-six cementless robotic-arm assisted (RA) TKAs were assessed. Bone resections were performed using the haptically controlled robotic arm. Alignment in the coronal and sagittal plane and resection depth of the distal femoral and proximal tibial cuts were recorded with a navigation planar probe. After final components were impacted, the probe was positioned on each implant surface to determine its alignment and positioning. RESULTS: The mean tibial resections and implanted tibial component's positioning were 0.4 mm (standard deviation, SD: 0.6) and 0.9 mm (SD: 0.8), respectively, higher than planned (p < 0.01). The tibial sagittal cut had 19/96 cases (19.8%) of ±1° outliers from plan. In 40/96 cases (41.7%), the tibial component was more prominent than planned of more than 1 mm. The mean femoral resections and impacted femoral component's positioning was 0.1 mm (SD: 0.8) and 0.2 mm (SD: 0.7), respectively, higher than planned. In 23/96 cases (24.0%), the femoral sagittal cut and femoral component coronal alignment deviated more than ±1° from plan. CONCLUSIONS: The computed tomography-based robotic-assisted TKA system showed good accuracy regarding bone preparation and component's positioning relative to the planning. Cementless tibial component impaction resulted in the most deviation from plan, with a large proportion of cases resulting in being more prominent than planned. LEVEL OF EVIDENCE: Level III.

Enhancing soft tissue balance: Evaluating robotic-assisted functional positioning in varus knees across flexion and extension with quantitative sensor-guided technology.

PURPOSE: Functional implant positioning (FIP) for total knee arthroplasty (TKA) is an evolution of kinematic alignment based on preoperative CT scan and robotic-assisted technology. This study aimed to assess the ligament balancing of image-based robotic-assisted TKA in extension, mid-flexion and flexion with an FIP using intraoperative sensor-guided technology. The hypothesis was that image-based robotic-assisted TKA performed by FIP would achieve ligament balancing all along the arc of knee flexion. METHODS: This prospective monocentric study included 47 consecutive patients with varus knees undergoing image-based robotic-assisted TKA performed with FIP. After robotic-assisted bone cuts, trial components were inserted, and soft tissue balance was assessed using sensor-guided technology at 10°, 45° and 90° of knee flexion. A mediolateral balanced knee was defined by an intercompartmental pressure difference (ICPD) ≤ 15 lbf and medial and lateral compartment pressure ≤60 lbf. The mean age was 71.6 years old ±6.7, the mean BMI was 29.0 kg/m2 ± 4.9 and the mean preoperative HKA was 174° ± 5 [159; 183]. RESULTS: The mean postoperative knee alignment was 177.0° ± 2.2° [172; 181]. There were 93.6% of balanced knees (n = 44) at 10 and 90° of knee flexion versus 76.6% (n = 36) at 45° of knee flexion with a significant difference (p = 0.014). Median ICPD at 10, 45 and 90° of knee flexion were, respectively, 7.0 (interquartile range [IQR]: 9), 11.0 (IQR: 9.5) and 8.0 (IQR: 9.0). Pairwise analyses revealed differences for ICPD at 45° versus ICPD at 10° (p = 0.003) and ICPD at 90° versus ICPD at 45° (p = 0.007). CONCLUSION: FIP with an image-based robotic-assisted system allowed the restoration of a well-balanced knee at 10° and 90° of flexion in varus knees. Nevertheless, some discrepancies occurred in midflexion, and more work is needed to understand ligament behaviour all along the arc of knee flexion. LEVEL OF EVIDENCE: Level II.

Functional alignment maximises advantages of robotic arm-assisted total knee arthroplasty with better patient-reported outcomes compared to mechanical alignment.

PURPOSE: Robotic arm-assisted total knee arthroplasty (RTKA) enables adjustment of implant position to achieve the surgeon's preferred alignment. However, the alignment concept that most effectively enhances patient satisfaction remains unclear. This study compares the clinical outcomes of patients who underwent functionally aligned RTKA (FA-RTKA), mechanically aligned conventional TKA (MA-CTKA) and mechanically aligned RTKA (MA-RTKA). METHODS: A prospectively collected database was retrospectively reviewed for patients who underwent primary TKA for knee osteoarthritis. One hundred and forty-seven knees were performed with MA-CTKA, followed by 72 consecutive knees performed with MA-RTKA, and subsequently, 70 consecutive knees performed with FA-RTKA were enrolled. After 1:1 propensity score matching of patient demographics, 70 knees were finally included in each group. The extent of additional soft tissue release during surgery was identified, and the Coronal Plane Alignment of the Knee classification was utilised to categorise the alignment. At the 1-year follow-up, patient-reported outcomes, including the pain Visual Analogue Scale, Knee Society Score, Western Ontario and McMaster Universities Arthritis Index and Forgotten Joint Score-12, were also compared among the groups. RESULTS: The FA-RTKA group showed significantly less additional soft tissue release than the MA-CTKA and MA-RTKA groups (15.7%, 38.6% and 35.7%, respectively; p = 0.006). Statistically significant differences in functional scores were observed in the postoperative 1-year clinical outcomes in favour of the FA-RTKA group, which had a significantly larger percentage of knees that maintained constitutional alignment and joint line obliquity than those of the other groups. CONCLUSIONS: Functionally aligned TKA showed superior 1-year postoperative patient-reported outcomes compared with those of conventional and robotic arm-assisted mechanically aligned TKA. Therefore, the advantage of RTKA is maximised when the implant positioning is based on functional alignment. The application of RTKA with mechanical alignment has been proven ineffective in improving the clinical outcomes of patients. LEVEL OF EVIDENCE: Level III.

A new gap balancing technique with functional alignment in total knee arthroplasty using the MAKO robotic arm system: a preliminary study.

BACKGROUND: Gap tension is an important factor influencing the clinical outcomes of total knee arthroplasty (TKA). Traditional mechanical alignment (MA) places importance on neutral alignment and often requires additional soft tissue releases, which may be related to patient dissatisfaction. Conversely, the functional alignment requires less soft tissue release to achieve gap balance. Conventional gap tension instruments present several shortcomings in practice. The aim of this study is to introduce a new gap balancing technique with FA using the modified spacer-based gap tool and the MAKO robotic arm system. METHODS: A total of 22 consecutive patients underwent primary TKA using the MAKO robotic arm system. The gap tension was assessed and adjusted with the modified spacer-based gap tool during the operation. Patient satisfaction was evaluated post-operatively with a 5-point Likert scale. Clinical outcomes including lower limb alignment, Knee Society Score (KSS) and Western Ontario and McMaster Universities Arthritis Index (WOMAC) were recorded before surgery, 3 months and 1 year after surgery. RESULTS: The range of motion (ROM) was significantly increased (p < 0.001) and no patients presented flexion contracture after the surgery. KSS and WOMAC score were significantly improved at 3 months and 1 year follow-up (p < 0.001 for all). During the surgery, the adjusted tibial cut showed more varus than planned and the adjusted femoral cut presented more external rotation than planned (p < 0.05 for both). The final hip-knee-ankle angle (HKA) was also more varus than planned (p < 0.05). CONCLUSIONS: This kind of spacer-based gap balancing technique accompanied with the MAKO robotic arm system could promise controlled lower limb alignment and improved functional outcomes after TKA.

Two-Dimensional Versus Three-Dimensional Preoperative Planning in Total Hip Arthroplasty.

BACKGROUND: Preoperative planning in total hip arthroplasty (THA) involves utilizing radiographs or advanced imaging modalities, including computerized tomography scans, for precise prediction of implant sizing and positioning. This study aimed to compare 3-dimensional (3D) versus 2-dimensional (2D) preoperative planning in primary THA with respect to key surgical metrics, including restoration of the horizontal and vertical center of rotation (COR), combined offset, and leg length. METHODS: This study included 60 patients undergoing primary THA for symptomatic hip osteoarthritis (OA), randomly allocated to either robotic arm-assisted or conventional THA. Digital 2D templating and 3D planning using the robotic software were performed for all patients. All measurements to evaluate the accuracy of templating methods were conducted on the preoperative computerized tomography scanogram, using the contralateral hip as a reference. Sensitivity analyses explored differences between 2D and 3D planning in patients who had superolateral or medial OA patterns. RESULTS: Compared to 2D templating, 3D templating was associated with less medialization of the horizontal COR (-1.2 versus -0.2 mm, P = .002) and more accurate restoration of the vertical COR (1.63 versus 0.3 mm, P < .001) with respect to the contralateral side. Furthermore, 3D templating was superior for planned restoration of leg length (+0.23 versus -0.74 mm, P = .019). Sensitivity analyses demonstrated that in patients who had medial OA, 3D planning resulted in less medialization of horizontal COR and less offset reduction. Conversely, in patients who had superolateral OA, there was less lateralization of horizontal COR and less offset increase using 3D planning. Additionally, 3D planning showed superior reproducibility for stem, acetabular cup sizes, and neck angle, while 2D planning often led to smaller stem and cup sizes. CONCLUSIONS: Our findings indicated higher accuracy in the planned restoration of native joint mechanics using 3D planning. Additionally, this study highlights distinct variances between the 2 planning methods across different OA pattern subtypes, offering valuable insights for clinicians employing 2D planning.

A Restricted Functional Balancing Technique for Total Knee Arthroplasty With a Varus Deformity: Does a Medial Soft-Tissue Release Result in a Worse Outcome?

BACKGROUND: A functional alignment technique for total knee arthroplasty (TKA) utilizes implant position modifications to balance the soft tissues. There is concern that, in some cases, extreme coronal and tibial component alignment could facilitate early implant failure. To be cautious, a restricted functional alignment may be used. The purpose of our study was to evaluate the results of TKA in patients who have varus deformities using a restricted functional alignment technique. We hypothesized that adding a medial soft-tissue release within restricted boundaries would not result in inferior outcomes. METHODS: A retrospective review was performed on robotic arm-assisted TKA patients with varus deformities utilizing a functional balancing strategy with a three-degree varus coronal limb and tibial component alignment restriction. Outcome scores of those patients still requiring a medial-soft tissue release were compared to those without for inferior outcomes. RESULTS: A total of 202 of 259 (78.0%) knees were able to be balanced without any medial soft-tissue release with an average final hip-knee-ankle alignment of 1.9° varus. The remaining 57 knees required a medial soft-tissue release. They had an average final hip-knee-ankle of 2.8° varus and an average medial proximal tibial angle of 2.5° varus. Comparing the cohorts without and with a release, at final follow-up averaging two years, there was not a statistically significant difference in Knee Society-Knee Score (97.7 and 98.4, P = .525), Functional Score (86.7 and 88.7, P = .514), Forgotten Joint Score (59.8 and 66.6, P = .136), and Knee Injury Osteoarthritis Outcome Survey for Joint Replacement Junior Score (79.5 and 84.8, P = .066). CONCLUSIONS: Utilizing a restrictive functional balancing strategy for TKA minimizes the need for soft-tissue releases and provides for excellent overall outcomes. An additional medial soft-tissue release can still be utilized without an inferior average two-year outcome.

Assistance Device Based on SSVEP-BCI Online to Control a 6-DOF Robotic Arm.

This paper explores the potential benefits of integrating a brain-computer interface (BCI) utilizing the visual-evoked potential paradigm (SSVEP) with a six-degrees-of-freedom (6-DOF) robotic arm to enhance rehabilitation tools. The SSVEP-BCI employs electroencephalography (EEG) as a method of measuring neural responses inside the occipital lobe in reaction to pre-established visual stimulus frequencies. The BCI offline and online studies yielded accuracy rates of 75% and 83%, respectively, indicating the efficacy of the system in accurately detecting and capturing user intent. The robotic arm achieves planar motion by utilizing a total of five control frequencies. The results of this experiment exhibited a high level of precision and consistency, as indicated by the recorded values of ±0.85 and ±1.49 cm for accuracy and repeatability, respectively. Moreover, during the performance tests conducted with the task of constructing a square within each plane, the system demonstrated accuracy of 79% and 83%. The use of SSVEP-BCI and a robotic arm together shows promise and sets a solid foundation for the development of assistive technologies that aim to improve the health of people with amyotrophic lateral sclerosis, spina bifida, and other related diseases.

Research on Multi-Hole Localization Tracking Based on a Combination of Machine Vision and Deep Learning.

In the process of industrial production, manual assembly of workpieces exists with low efficiency and high intensity, and some of the assembly process of the human body has a certain degree of danger. At the same time, traditional machine learning algorithms are difficult to adapt to the complexity of the current industrial field environment; the change in the environment will greatly affect the accuracy of the robot's work. Therefore, this paper proposes a method based on the combination of machine vision and the YOLOv5 deep learning model to obtain the disk porous localization information, after coordinate mapping by the ROS communication control robotic arm work, in order to improve the anti-interference ability of the environment and work efficiency but also reduce the danger to the human body. The system utilizes a camera to collect real-time images of targets in complex environments and, then, trains and processes them for recognition such that coordinate localization information can be obtained. This information is converted into coordinates under the robot coordinate system through hand-eye calibration, and the robot is then controlled to complete multi-hole localization and tracking by means of communication between the upper and lower computers. The results show that there is a high accuracy in the training and testing of the target object, and the control accuracy of the robotic arm is also relatively high. The method has strong anti-interference to the complex environment of industry and exhibits a certain feasibility and effectiveness. It lays a foundation for achieving the automated installation of docking disk workpieces in industrial production and also provides a more favorable choice for the production and installation of the process of screw positioning needs.

Sensor Fault Reconstruction Using Robustly Adaptive Unknown-Input Observers.

Sensors are a key component in industrial automation systems. A fault or malfunction in sensors may degrade control system performance. An engineering system model is usually disturbed by input uncertainties, which brings a challenge for monitoring, diagnosis, and control. In this study, a novel estimation technique, called adaptive unknown-input observer, is proposed to simultaneously reconstruct sensor faults as well as system states. Specifically, the unknown input observer is used to decouple partial disturbances, the un-decoupled disturbances are attenuated by the optimization using linear matrix inequalities, and the adaptive technique is explored to track sensor faults. As a result, a robust reconstruction of the sensor fault as well as system states is then achieved. Furthermore, the proposed robustly adaptive fault reconstruction technique is extended to Lipschitz nonlinear systems subjected to sensor faults and unknown input uncertainties. Finally, the effectiveness of the algorithms is demonstrated using an aircraft system model and robotic arm and comparison studies.

A feasibility cadaver study for placing screws in various pelvic osseous fracture pathways using a robotic arm.

INTRODUCTION: The use of a robotic system for the placement of pedicle screws in spine surgeries is well documented in the literature. However, there is only a single report in the United States describing the use of a robotic system to place two screws in osseous fixation pathways (OFPs) commonly used in the treatment of pelvic and acetabular fractures in a simulated bone model. The purpose of this study was to demonstrate the use of a robotic system to place screws in multiple, clinically relevant OFPs in a cadaveric model and to quantitatively measure accuracy of screw placement relative to the preoperative plan. METHODS: A single cadaveric specimen was obtained for the purpose of this study. All surrounding soft tissues were left intact. Screws were placed in OFPs, namely iliosacral (IS), trans-sacral (TS), Lateral Compression-II (LC-II), antegrade anterior column (AC) and antegrade posterior column (PC) of the right hemipelvis using standard, fluoroscopically assisted percutaneous or mini-open technique. Following the placement of screws into the right hemipelvis using standard techniques, screws were planned and placed in the same OFPs of the contralateral hemipelvis using the commercially available ExcelsiusGPS® robotic system (Globus Medical Inc., Audubon, PA). After robotic-assisted screw placement, a post-procedure CT scan was obtained to evaluate actual screw placement against the pre-procedure plan. A custom-made image analysis program was devised to measure screw tip/tail offset and angular offset on axial and sagittal planes. RESULTS: For different OFPs, the mean tip offset, tail offset and angular offsets were 1.6 ± 0.9 mm (Range 0.0-3.6 mm), 1.4 ± 0.4 mm (Range 0.3-2.5 mm) and 1.1 ± 0.4° (Range 0.5-2.1), respectively. CONCLUSION: In this feasibility study, surgeons were able to place screws into the clinically relevant fracture pathways of the pelvis using ExcelsiusGPS® for robotic-assisted surgery. The measured accuracy was encouraging; however, further investigation is needed to demonstrate that robotic-assisted surgery can be used to successfully place the screws in the bony corridors of the pelvis to treat traumatic pelvic injuries.

Robotic arm-assisted versus conventional total knee arthroplasty: comparing complications, costs, and postoperative opioid use in propensity-matched cohorts.

PURPOSE: Limited literature exists substantiating benefits of robotic arm-assisted total knee arthroplasty (raTKA) over conventional total knee arthroplasty (cTKA). This study compared postoperative pain, complications, and costs between patients undergoing raTKA and cTKA using large, propensity score-matched cohorts. We hypothesize that the raTKA cohort will be associated with lower pain, lower anemia, and similar cost and other complications. METHODS: A commercially available patient database was used for this study. Patients with raTKA and cTKA were identified with current procedural terminology and international classification of diseases (ICD-9/ICD-10) codes. Exclusions and propensity score matching were applied to mitigate confounding bias. Complication rates, costs, and postoperative opioid uses were then compared between groups. RESULTS: Compared with patients with cTKAs (n = 31,105), patients with raTKAs (n = 6,221) had less postoperative opioid use (p < 0.01), lower rates of postoperative acute renal failure (OR 0.71; p < 0.01), anemia (OR 0.75; p < 0.01), and periprosthetic joint infection (OR 0.59; p = 0.04), and lower index costs ($875 vs. $1,169, p < 0.01). CONCLUSION: RaTKA was associated with less postoperative pain and complications compared with cTKA.

Image-based robotic-arm assisted unicompartmental knee arthroplasty provides high survival and good-to-excellent clinical outcomes at minimum 10 years follow-up.

PURPOSE: The purpose of the present study was to determine the incidence of revision and report on clinical outcomes at a minimum of 10 years follow-up in patients who had received a medial unicompartmental knee arthroplasty (UKA) with an three-dimensional image-based robotic system. METHODS: A total of 239 patients (247 knees), who underwent medial robotic-arm assisted (RA)-UKA at a single center between April 2011 and June 2013, were assessed. The mean age at surgery was 67.0 years (SD 8.4). Post-operatively, patients were administered the Forgotten Joint Score-12 (FJS-12) and asked about their satisfaction (from 1 to 5). Post-operative complications were recorded. Failure mechanisms, revisions and reoperations were collected. Kaplan-Meier survival curves were calculated, considering revision as the event of interest. RESULTS: A total of 188 patients (196 knees) were assessed at a mean follow-up of 11.1 years (SD 0.5, range 10.0-11.9), resulting in a 79.4% follow-up rate. Seven RA-UKA underwent revision, resulting in a survivorship rate of 96.4% (CI 94.6%-99.2%). Causes of revision included aseptic loosening (2 cases), infection (1 case), post-traumatic (1 case), and unexplained pain (3 cases). The mean FJS-12 and satisfaction were 82.2 (SD 23.9) and 4.4 (SD 0.9), respectively. Majority of cases (174/196, 88.8%) attained the Patient Acceptable Symptoms State (PASS, FJS-12 > 40.63). Male subjects had a higher probability of attaining a "forgotten joint" (p < 0.001) and high satisfaction (equal to 5, p < 0.05), when compared to females. CONCLUSIONS: Three-dimensional image-based RA-UKA demonstrated high implant survivorship and good-to-excellent clinical outcomes at minimum 10 years follow-up. Pain of unknown origin represented the most common reason for RA-UKA revision. LEVEL OF EVIDENCE: III.

Functional alignment with robotic­arm 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.

Use of intraoperative technology in total knee arthroplasty is not associated with reductions in postoperative pain.

PURPOSE: Our systematic review and meta-analysis sought to assess how technology-assistance impacts (1) post-operative pain and (2) opioid use in patients undergoing primary total knee arthroplasty (TKA). METHODS: Four online databases were queried for studies published up to October 2021 that reported on pain and opioid usage between technology-assisted and manual TKA (mTKA) patients. Mantel-Haenszel (M-H) models were utilized to calculate pooled mean difference (MDs) and 95% confidence interval (CIs). Subgroup analyses were conducted to isolate robotic-arm assisted (RAA) and computed-assisted navigation (CAN) cohorts. Risk of bias was assessed for all included non-randomized studies with the Methodological Index for Non-Randomized Studies (MINORS) tool. For the randomized control trials included in our study, the Detsky scale was applied. RESULTS: Our analysis included 31 studies, reporting on a total of 761,300 TKAs (mTKA: n = 753,554; Computer-Assisted Navigation (CAN): n = 1,309; Robotic-Arm Assisted (RAA): n = 6437). No differences were demonstrated when evaluating WOMAC (MD: 0.00, 95% CI - 0.69 to 0.69; p = 1.00), KSS (MD: 0.01, 95% CI - 1.46 to 1.49; p = 0.99), KOOS (MD - 2.91, 95% CI - 6.17 to 0.34; p = 0.08), and VAS (MD - 0.54, 95% CI - 1.01 to - 0.007; p = 0.02) pain scores between cohorts. There was mixed evidence regarding how opioid consumption differed between TKA techniques. CONCLUSION: The present analysis demonstrated no difference in terms of pain across a variety of utilized patient-reported pain measurements. However, there were mixed results regarding how opioid consumption varied between manual and technology-assisted cohorts, particularly in the immediate post-operative period. LEVEL OF EVIDENCE: III.

Combination of a High Residual Varus and Joint-Line Lowering Strongly Increases the Risk of Early Implant Failure in Medial Unicompartmental Knee Arthroplasty.

BACKGROUND: Outliers in implant positioning, malalignment, and joint line height change are risk factors for unicompartmental knee arthroplasty (UKA) failure. However, their relationships and patterns in large datasets remain unexplored. This study assessed medial UKA survival in a large cohort and explored associated risk factors. METHODS: This was a retrospective cohort study on medial UKA patients (2011 to 2019). Radiological outcomes included tibial implant positioning in the coronal plane, posterior tibial slope, residual knee deformity, and joint line restitution. Survival rate at last follow-up was recorded. Multinomial logistic regression analyzed risk factors, incorporating demographic and univariate analysis data. RESULTS: Three hundred and sixty-six knees met inclusion criteria, with 10 lost to follow-up (2.7%). Mean follow-up was 61.3 months [24.1 to 135.1]. 5- and 10-year implant survival rates were 92% ± 1.6 and 88.4% ± 3.8, respectively. Multivariate analysis identified post-operative hip-knee-ankle angle (HKA) ≤ 175° (OR = 5.30 [1.64 to 17.13], P = .005) and joint line lowering ≥2 mm (OR = 8.86 [2.06 to 38.06]) as significant risk factors for tibial implant failure. Their combination carried a significantly high risk of failure (OR = 10.3 [3.1 to 34.3]). Post-operative HKA < 175° was common in knees with pre-operative HKA < 172°. CONCLUSION: This study reports encouraging 5- and 10-year survival outcomes for medial UKA. Tibial loosening was the main reason for revision. Patients with joint line lowering ≥ 2 mm and post-operative HKA ≤ 175° were at high risk of tibial implant failure. Surgeons should carefully restore the joint line in cases of pre-operative HKA < 172°.

Patient-Reported Outcome Measures in Conventional Total Hip Arthroplasty Versus Robotic-Arm Assisted Arthroplasty: A Prospective Cohort Study With Minimum 3 Years' Follow-Up.

BACKGROUND: Robotic-arm assisted total hip arthroplasty (RO THA) has been shown to improve the accuracy of component positioning compared with conventional total hip arthroplasty (CO THA). This study reports Patient-Reported Outcome Measures (PROMs) of a previous trial that showed that RO THA was associated with improved accuracy and reduced outliers in acetabular component positioning compared with CO THA. METHODS: This prospective cohort study included 50 patients undergoing CO THA versus 50 patients receiving RO THA. The Oxford hip score, Forgotten Joint Score (FJS), University of California at Los Angeles hip score were recorded at a minimum of 3 years following surgery. RESULTS: At minimum 3 years follow-up, there was no statistically significant difference in CO THA versus RO THA with respect to the Oxford hip score [median 42(6.25) versus 41(5.5), P = .914]; FJS [89 (9.25) versus 86 (9), P = .065], and University of California at Los Angeles score [median 7.5 (3) versus 7 (2), P = .381]. None of the study patients had dislocations or underwent revision surgery within 3 years follow-up. CONCLUSION: The previously reported improvement in accuracy of acetabular component in this study population did not translate to statistically significant improvements in PROMs. Patients in both groups achieved excellent PROMs and there was a trend towards higher FJS scores postoperatively in the RO THA group that did not reach statistical significance. Further studies are needed to assess the significance of these findings on longer-term clinical outcomes and implant survivorships, and also to explore the impact of the enhanced RO THA workflow and functional implant positioning on these outcomes.