Perioperative safety and efficacy of robot-assisted total hip arthroplasty in ERAS-managed patients: a pilot study.

AIMS: Robot-assisted total hip arthroplasty (rTHA) boasts superior accuracy in implant placement, but there is a lack of effective assessment in perioperative management in the context of enhanced recovery after surgery (ERAS). This study aimed to compare the effectiveness and safety of rTHA versus conventional total hip arthroplasty (cTHA) in ERAS-managed patients. METHODS: In this prospective trial, a total of 60 eligible patients aged between 18 and 80 years were randomly divided into two groups to undergo either rTHA or cTHA. The primary outcomes included blood loss parameters. Secondary outcomes were the duration of the operation, surgical time, WOMAC pain score, WOMAC stiffness score, WOMAC physical function score, Harris score, and postoperative complications. RESULTS: The study cohort analyzed 59 eligible participants, 30 of whom underwent rTHA and 29 of whom underwent cTHA. Analysis could not be conducted for one patient due to severe anemia. Notably, the cTHA group had a significantly shorter surgical time than the rTHA group (69.49 ± 18.97 vs. 104.20 ± 19.63 min, P < 0.001). No significant differences were observed between the rTHA and cTHA groups for blood loss parameters, including total blood loss (1280.30 ± 404.01 vs. 1094.86 ± 494.39 ml, P = 0.137) and drainage volume (154.35 ± 121.50 vs. 159.13 ± 135.04 ml, P = 0.900), as well as intraoperative blood loss (126.67 ± 38.80 vs. 118.52 ± 60.68 ml, P = 0.544) and hidden blood loss (982.43 ± 438.83 vs. 784.00 ± 580.96 ml, P = 0.206). Only one patient in the cTHA group required allogeneic blood transfusion. At 3 months postoperatively, both groups showed improvements in WOMAC pain score, WOMAC stiffness score, WOMAC physical function score, and Harris score, with no significant differences found between the two groups. Few complications were reported in both groups without significant differences. CONCLUSIONS: Despite the longer surgical time, rTHA did not negatively affect blood loss, pain, or functional recovery or lead to an increased risk of complications in ERAS-managed patients, suggesting that rTHA can be safely and effectively incorporated into an ERAS program for primary THA.

Robotic arm-assisted total hip arthroplasty for preoperative planning and intraoperative decision-making.

AIMS: This article aimed to explore the efficacy of robotic arm-assisted total hip arthroplasty (THA) in improving preoperative planning and intraoperative decision-making. METHODS: In this single-center, prospective, randomized clinical controlled trial, 60 patients were randomly divided into two groups: conventional THA (cTHA) and robotic arm-assisted THA (rTHA). The rTHA underwent procedures using a robot-assisted surgical system, which generated three-dimensional models to determine the most appropriate prosthesis size and position. The standard process of replacement was executed in cTHA planned preoperatively via X-ray by experienced surgeons. Differences between predicted and actual prosthetic size, prosthetic position, and leg length were evaluated. RESULTS: Sixty patients were included in the study, but one patient was not allocated due to anemia. No significant preoperative baseline data difference was found between the two groups. The actual versus predicted implantation size of both groups revealed that 27/30 (90.0%) in the rTHA group and 25/29 (86.2%) in the cTHA group experienced complete coincidence. The coincidence rate for the femoral stem was higher in the rTHA group (83.3%) than that in the cTHA group (62.7%). Between the actual and predicted rTHA, the difference in anteversion/inclination degree (< 6°) was largely dispersed, while cTHA was more evenly distributed in degree (< 9°). The differences in leg length between the surgical side and contralateral side showed a significant deviation when comparing the two groups (P = 0.003), with 0.281 (- 4.17 to 3.32) mm in rTHA and 3.79 (1.45-6.42) mm in cTHA. CONCLUSION: Robotic arm-assisted total hip arthroplasty can be valuable for preoperative planning and intraoperative decision-making.

[A cadaveric experimental study on domestic robot-assisted total knee arthroplasty].

OBJECTIVE: To simulate and validate the performance, accuracy, and safety of the Yuanhua robotic-assisted total knee arthroplasty system (YUANHUA-TKA) through cadaver-based experiment, thus optimizing the robotic system for the future human clinical application. METHODS: Six unilateral adult cadaver specimens of the lower limbs were scanned by three-dimensional CT before the experiment, and then the three-dimensional models of femur and tibia were obtained by using the preoperative software of YUANHUA-TKA system, so as to plan the type of prosthesis implant, the osteotomy volume and osteotomy angles [hip-knee-ankle angle (HKA), coronal frontal femoral component (FFC) and frontal tibial component (FTC)], the ideal value of HKA was set to 180°, and of FFC and FTC were set to 90°, respectively. The operator could further confirm the osteotomy plan according to the intraoperative situation before osteotomy, and then install the prosthesis after completing the osteotomy in each plane with the assistance of YUANHUA-TKA system. At last, the X-ray films of hip joint, knee joint, and ankle joint were taken and stitched into the full length X-ray film of the lower limb, and HKA, coronal FFC and FTC were measured. RESULTS: During the experiment, YUANHUA-TKA system ran stably. All sections of femur and tibia were smooth and no ligament injury was found. After operation, the HKA was 177.1°-179.7°, FFC was 87.9°-91.4°, and FTC was 87.3°-91.4°, which were within ±3° from the ideal values of preoperative planning. CONCLUSION: The YUANHUA-TKA system can assist the surgeon to carry out precise osteotomy according to the preoperative planned value, which has a good auxiliary effect for total knee arthroplasty. It is expected to assist joint surgeons to improve the surgical accuracy in clinical application.

[An animal experimental study on domestic robot-assisted total knee arthroplasty].

OBJECTIVE: To evaluate the performance, safety, and precision of the Yuanhua robotic-assisted total knee arthroplasty system (YUANHUA-TKA) through animal experiments, which will provide reference data for human clinical trials. METHODS: Six 18-month-old goats, weighing 30-35 kg, were used in this study. The experimental study was divided into two parts: the preoperative planning and intraoperative bone resection. CT scans of the goats' lower extremities were firstly performed before the experiments. Then the CT scans were segmented to generate the femoral and tibial three-dimensional (3D) models in the YUANHUA-TKA system. The volumes and angles of each resection plane on the femur and tibia were planned. The bone resection was finally implemented under the assistance of the YUANHUA-TKA system. After completing all bone resections, the lower extremities of each goat were taken to have CT scans. By comparing the femoral and tibial 3D models before and after the experiments, the actual bone resection volumes and angles were calculated and compared with the preoperative values. RESULTS: During the experiments, no abnormal bleeding was found; the YUANHUA-TKA system ran smoothly and stably and was able to stop moving and keep the osteotomy in the safe zone all the time. After the experiment, the resection planes were observed immediately and found to be quite flat. There was no significant difference between the planned and actual osteotomy thickness and osteotomy angle ( P>0.05); the error of the osteotomy thickness was less than 1 mm, and the error of the osteotomy angle was less than 2°. CONCLUSION: The YUANHUA-TKA system can assist the surgeons to perform osteotomy following the planned thickness and angle values. It is expected to assist surgeons to implement more accurate and efficient osteotomy in the future clinical applications.

Safe and Robust Mobile Robot Navigation in Uneven Indoor Environments.

Complex environments pose great challenges for autonomous mobile robot navigation. In this study, we address the problem of autonomous navigation in 3D environments with staircases and slopes. An integrated system for safe mobile robot navigation in 3D complex environments is presented and both the perception and navigation capabilities are incorporated into the modular and reusable framework. Firstly, to distinguish the slope from the staircase in the environment, the robot builds a 3D OctoMap of the environment with a novel Simultaneously Localization and Mapping (SLAM) framework using the information of wheel odometry, a 2D laser scanner, and an RGB-D camera. Then, we introduce the traversable map, which is generated by the multi-layer 2D maps extracted from the 3D OctoMap. This traversable map serves as the input for autonomous navigation when the robot faces slopes and staircases. Moreover, to enable robust robot navigation in 3D environments, a novel camera re-localization method based on regression forest towards stable 3D localization is incorporated into this framework. In addition, we utilize a variable step size Rapidly-exploring Random Tree (RRT) method which can adjust the exploring step size automatically without tuning this parameter manually according to the environment, so that the navigation efficiency is improved. The experiments are conducted in different kinds of environments and the output results demonstrate that the proposed system enables the robot to navigate efficiently and robustly in complex 3D environments.

Experimental Validation of Motor Primitive-Based Control for Leg Exoskeletons during Continuous Multi-Locomotion Tasks.

An emerging approach to design locomotion assistive devices deals with reproducing desirable biological principles of human locomotion. In this paper, we present a bio-inspired controller for locomotion assistive devices based on the concept of motor primitives. The weighted combination of artificial primitives results in a set of virtual muscle stimulations. These stimulations then activate a virtual musculoskeletal model producing reference assistive torque profiles for different locomotion tasks (i.e., walking, ascending stairs, and descending stairs). The paper reports the validation of the controller through a set of experiments conducted with healthy participants. The proposed controller was tested for the first time with a unilateral leg exoskeleton assisting hip, knee, and ankle joints by delivering a fraction of the computed reference torques. Importantly, subjects performed a track involving ground-level walking, ascending stairs, and descending stairs and several transitions between these tasks. These experiments highlighted the capability of the controller to provide relevant assistive torques and to effectively handle transitions between the tasks. Subjects displayed a natural interaction with the device. Moreover, they significantly decreased the time needed to complete the track when the assistance was provided, as compared to wearing the device with no assistance.

Gait Phase Estimation Based on Noncontact Capacitive Sensing and Adaptive Oscillators.

This paper presents a novel strategy aiming to acquire an accurate and walking-speed-adaptive estimation of the gait phase through noncontact capacitive sensing and adaptive oscillators (AOs). The capacitive sensing system is designed with two sensing cuffs that can measure the leg muscle shape changes during walking. The system can be dressed above the clothes and free human skin from contacting to electrodes. In order to track the capacitance signals, the gait phase estimator is designed based on the AO dynamic system due to its ability of synchronizing with quasi-periodic signals. After the implementation of the whole system, we first evaluated the offline estimation performance by experiments with 12 healthy subjects walking on a treadmill with changing speeds. The strategy achieved an accurate and consistent gait phase estimation with only one channel of capacitance signal. The average root-mean-square errors in one stride were 0.19 rad (3.0% of one gait cycle) for constant walking speeds and 0.31 rad (4.9% of one gait cycle) for speed transitions even after the subjects rewore the sensing cuffs. We then validated our strategy in a real-time gait phase estimation task with three subjects walking with changing speeds. Our study indicates that the strategy based on capacitive sensing and AOs is a promising alternative for the control of exoskeleton/orthosis.

Gastrocnemius myoelectric control of a robotic hip exoskeleton.

In this paper we present a novel EMG-based assistive control strategy for lower-limb exoskeletons. An active pelvis orthosis (APO) generates torque profiles for the hip flexion motion assistance, according to the Gastrocnemius Medialis EMG signal. The strategy has been tested on one healthy subject: experimental results show that the user is able to reduce his muscular activation when the assistance is switched on with respect to the free walking condition.

Fuzzy-logic-based hybrid locomotion mode classification for an active pelvis orthosis: Preliminary results.

In this paper, we present a fuzzy-logic-based hybrid locomotion mode classification method for an active pelvis orthosis. Locomotion information measured by the onboard hip joint angle sensors and the pressure insoles is used to classify five locomotion modes, including two static modes (sitting, standing still), and three dynamic modes (level-ground walking, ascending stairs, and descending stairs). The proposed method classifies these two kinds of modes first by monitoring the variation of the relative hip joint angle between the two legs within a specific period. Static states are then classified by the time-based absolute hip joint angle. As for dynamic modes, a fuzzy-logic based method is proposed for the classification. Preliminary experimental results with three able-bodied subjects achieve an off-line classification accuracy higher than 99.49%.