Robot-assisted gait self-training: assessing the level achieved

This paper presents the technological status of robot-assisted gait self-training under real clinical environment conditions. A successful rehabilitation after surgery in hip endoprosthetics comprises self-training of the lessons taught by physiotherapists. While doing this, immediate feedback to the patient about deviations from the expected physiological gait pattern during training is important. Hence, the Socially Assistive Robot (SAR) developed for this type of training employs task-specific, user-centered navigation and autonomous, real-time gait feature classification techniques to enrich the self-training through companionship and timely corrective feedback. The evaluation of the system took place during user tests in a hospital from the point of view of technical benchmarking, considering the therapists’ and patients’ point of view with regard to training motivation and from the point of view of initial findings on medical efficacy as a prerequisite from an economic perspective. In this paper, the following research questions were primarily considered: Does the level of technology achieved enable autonomous use in everyday clinical practice? Has the gait pattern of patients who used additional robot-assisted gait self-training for several days been changed or improved compared to patients without this training? How does the use of a SAR-based self-training robot affect the motivation of the patients

Polyhexanide and hydrogen peroxide inhibit proteoglycan synthesis of human chondrocytes

The use of local antiseptics is a common method in septic joint surgery. We tested polyhexanide and hydrogen peroxide, two of the most frequently used antiseptics with high efficacy and low toxicity. The purpose of this study was to evaluate the effects of both antiseptics on the extracellular cartilaginous matrix synthesis of human chondrocytes. Chondrocytes were isolated from donated human knee joints, embedded in alginate beads, and incubated for 10 and 30 minutes with polyhexanide (0.04%), hydrogen peroxide (3%), or phosphate-buffered saline (PBS) for control. Cartilaginous matrix production was quantified through light microscopic analysis of Alcian blue staining. Cell number and morphology were detected by histological analysis. Chondrocytes showed a decreased intensity of blue colouring after antiseptic treatment versus PBS. In contrast to that, neither the cell number per view field nor the cell morphology differed between the groups. Polyhexanide has more toxic potential than hydrogen peroxide. Based on the fact that the cell number and morphology was not altered by the substances at the examined concentrations, the lower intensity of Alcian blue staining of treated chondrocytes indicates a decreased cartilage-specific matrix synthesis by polyhexanide more than by hydrogen peroxide and control

Mobile robot-based gait training after total hip arthroplasty (THA) improves walking in biomechanical gait analysis

There are multiple attempts to decrease costs in the healthcare system while maintaining a high treatment quality. Digital therapies receive increasing attention in clinical practice, mainly relating to home-based exercises supported by mobile devices, eventually in combination with wearable sensors. The aim of this study was to determine if patients following total hip arthroplasty (THA) could benefit from gait training on crutches conducted by a mobile robot in a clinical setting. Method: This clinical trial was conducted with 30 patients following total hip arthroplasty. Fifteen patients received the conventional physiotherapy program in the clinic (including 5 min of gait training supported by a physiotherapist). The intervention group of 15 patients passed the same standard physiotherapy program, but the 5-min gait training supported by a physiotherapist was replaced by 2 × 5 min of gait training conducted by the robot. Length of stay of the patients was set to five days. Biomechanical gait parameters of the patients were assessed pre-surgery and upon patient discharge. Results: While before surgery no significant difference in gait parameters was existent, patients from the intervention group showed a significant higher absolute walking speed (0.83 vs. 0.65 m/s, p = 0.029), higher relative walking speed (0.2 vs. 0.16 m/s, p = 0.043) or shorter relative cycle time (3.35 vs. 3.68 s, p = 0.041) than the patients from the control group. Conclusion: The significant higher walking speed of patients indicates that such robot-based gait training on crutches may shorten length of stay (LOS) in acute clinics. However, the number of patients involved was rather small, thus calling for further studies

CTLA-4 mediates inhibitory function of mesenchymal stem/stromal cells

Mesenchymal stem/stromal cells (MSCs) are stem cells of the connective tissue, possess a plastic phenotype, and are able to differentiate into various tissues. Besides their role in tissue regeneration, MSCs perform additional functions as a modulator or inhibitor of immune responses. Due to their pleiotropic function, MSCs have also gained therapeutic importance for the treatment of autoimmune diseases and for improving fracture healing and cartilage regeneration. However, the therapeutic/immunomodulatory mode of action of MSCs is largely unknown. Here, we describe that MSCs express the inhibitory receptor CTLA-4 (cytotoxic T lymphocyte antigen 4). We show that depending on the environmental conditions, MSCs express different isoforms of CTLA-4 with the secreted isoform (sCTLA-4) being the most abundant under hypoxic conditions. Furthermore, we demonstrate that the immunosuppressive function of MSCs is mediated mainly by the secretion of CTLA-4. These findings open new ways for treatment when tissue regeneration/fracture healing is difficult

BMP-2 Dependent Increase of Soft Tissue Density in Arthrofibrotic TKA

Arthrofibrosis after total knee arthroplasty (TKA) is difficult to treat, as its aetiology remains unclear. In a previous study, we established a connection between the BMP-2 concentration in the synovial fluid and arthrofibrosis after TKA. The hypothesis of the present study was, therefore, that the limited range of motion in arthrofibrosis is caused by BMP-2 induced heterotopic ossifications, the quantity of which is dependent on the BMP-2 concentration in the synovial fluid