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An extensive investigation of the interaction of thermoplastic olefin (TPO) compounds with high frequency radar wave has been conducted to understand how TPO materials affect radar sensor efficiency, an important function for vehicle safety and especially the advancement of autonomous vehicles. In this article, the effect of major ingredients of a TPO on its dielectric properties was studied, and then a wide range of TPO compounds were evaluated for their radar transmittance or attenuation. It was demonstrated that the characteristics of polypropylene (PP) resin and rubber have little impact on the dielectric properties of a TPO, thus minimal influence on TPO's radar transparency, while increasing the talc loading in the compound increases the dielectric constant of the TPO. The TPO materials containing talc from 7% up to 34% were found to have dielectric constants ranging from 2.30 to 2.70 and nearly zero dielectric loss. Experiments confirmed that parts molded with these materials are transparent to high frequency radar wave at optimized thicknesses. Some pigments for coloring the materials also affect dielectric properties of TPOs, thus radar transmittance, with metal pigments showing the most impact. Finally, commercial TPO products are shown to have great batch to batch consistency in radar transmittance at a selected part thickness. [ABSTRACT FROM AUTHOR]

The results of the Phase III DESTINY-Breast04 trial of trastuzumab deruxtecan (T-DXd) are leading to a shift in both the classification and treatment of human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer. In this trial, T-DXd was associated with a substantial survival benefit among patients with hormone receptor-positive and hormone receptor-negative disease and low expression of HER2, a biomarker previously considered unactionable in this treatment setting. Herein, we discuss the evolving therapeutic pathway for HER2-low disease, ongoing clinical trials, and the potential challenges and evidence gaps arising with treatment of this patient population. [ABSTRACT FROM AUTHOR]

The reduced cost of trastuzumab biosimilars has led to increased adoption for HER2-positive breast cancer. This review of trastuzumab biosimilars encompasses this development and real world clinical data in early breast cancer. In addition, we present a retrospective study evaluating the total pathological complete response (tpCR) rates (lack of residual invasive cancer in resected breast tissue and axillary nodes), of MYL-1401O to reference trastuzumab (TRZ) in the neoadjuvant setting for HER2+ early breast cancer (EBC) in Alberta, Canada. Neoadjuvant patients with HER2+ EBC treated with TRZ from November 2018–October 2019 and MYL-1401O from December 2019–September 2020 were identified. Logistic regression was used to control for variables potentially associated with tpCR: trastuzumab product, age, pre-operative T- and N-stage, grade, hormone receptor (HR)-status, HER2-status, chemotherapy regimen, and chemotherapy completion. tpCR was 35.6% in the MYL-1401O group (n = 59) and 40.3% in the TRZ (n = 77) group, p = 0.598. After controlling for clinically relevant variables, there was no significant difference in the odds of achieving tpCR in patients treated with TRZ versus MYL-1401O (OR 1.1, 95% CI 0.5–2.4, p = 0.850). tpCR rates were similar for patients treated with MYL-1401O compared to trastuzumab in our real world study of HER2+ neoadjuvant EBC and comparable to pivotal phase 3 trials. [ABSTRACT FROM AUTHOR]

Background: Synovial fluid aspiration is a routine practice used by most orthopaedic surgeons to aid in the diagnosis of joint infection. In patients for whom there is a low pretest probability of infection, a positive culture-particularly if it is a broth-only culture-may be considered a contaminant, especially if the bacterial species are skin pathogens. To our knowledge no study has evaluated the incidence of contamination of aspirations from the native knee.Questions/purposes: What is the frequency of false-positive cultures among knee aspirations of the native knee?Methods: Two hundred patients, with a total of 200 knees, with the diagnosis of degenerative osteoarthritis undergoing a total knee arthroplasty (TKA) were identified for this study. None of these patients had symptoms, signs, or laboratory studies to suggest the presence of joint infection; a positive culture in this population therefore would be considered contaminated. Thirty-two (16%) patients were excluded secondary to a dry aspiration. One patient was enrolled in the study but did not have the knee aspirated and another patient's specimen was accidentally discarded. Each knee was aspirated under sterile conditions before performing the TKA. The fluid was sent for cell count and culture. If insufficient fluid was obtained for both cell count and culture, culture was performed rather than cell count.Results: There were no false-positive cultures (zero of 166 [0%]) in aspirations of native knees.Conclusions: Our study would indicate that when done properly under sterile technique, cultures taken from knee arthrocentesis in patients without prosthetic joints should not be affected by perceived contaminant species. A positive specimen finding on culture should raise a strong suspicion of bacterial septic arthritis. Future studies should include more specimens as well as knees with prior TKA to help further identify the rate of false-positive cultures in knee arthrocentesis in both populations.Level Of Evidence: Level I, diagnostic study. [ABSTRACT FROM AUTHOR]

Background: The risk of early complications is high after monoblock acetabular metal-on-metal (MoM) THA revisions. However, there is a paucity of evidence regarding clinical complications after isolated head-liner exchange of modular MoM THA.Questions/purposes: The purposes of this study were (1) to describe the frequency of early complications after an isolated head-liner exchange revision of modular MoM THA; and (2) to determine whether patients who experienced complications or dislocation after head-liner exchanges had higher serum chromium (Cr) or cobalt (Co) ion levels than those who did not.Methods: A review of our institution's total joint registry retrospectively identified 53 patients who underwent 54 liner exchange revisions of a modular acetabular MoM THA. The study period was from April 2008 to April 2016 at a single tertiary care center. During this period, isolated head-liner exchanges (rather than more extensive revisions) were performed in patients if they did not have evidence of loosening of the acetabular or femoral components. Reasons for revision surgery included pain, mechanical symptoms, radiographic evidence of osteolysis, elevated serum metal ions, and MRI abnormalities with 40 of the 54 hips having pain or mechanical symptoms and 38 of 54 hips having multiple reasons for revision before surgery. Patients were excluded if they did not meet the minimum postrevision followup or had the modular liner exchange secondary to infection. All revisions were from a single manufacturer with one head-liner exchange of a MoM THA from another manufacturer excluded during the study period. The mean time from index MoM THA to modular exchange was 96 (SD ± 36) months. Because the focus of this study was early complications, we had a minimum 90-day followup duration for inclusion. Mean followup after revision was 15 months (SD ± 12); a total of 56% (30 of 54) had followup of at least 12 months' duration. Complications (dislocation, infection) and reoperations were obtained by chart review performed by individuals other than the treating physician(s). Serum metal ion levels were obtained before head-liner exchange. The median serum Cr and Co levels were 6 µg/L (range, 0-76 µg/L) and 12 µg/L (range, 0-163 µg/L), respectively.Results: Of the 54 revision THAs, 15 (28%) developed complications. Nine (17%) occurred within 90 days of the revision surgery and 11 (20%) resulted in reoperation. The most common complication was dislocation (12 of 54 [22%]) with recurrent dislocation noted in eight of these 12 patients. All patients with recurrent dislocation continued to dislocate and underwent repeat revision. Patients with dislocation had higher median serum Cr and Co ion levels than those without dislocation (Cr: 24 [range, 11-76] versus 4 [range, 0-70], p = 0.001 [95% confidence interval {CI}, 10-57]; Co: 41 [range, 6-163] versus 8 [range, 0-133], p = 0.016 [95% CI, 6-141]). Three (6%) of the 54 patients underwent repeat surgery for deep space infection.Conclusions: Complications and reoperations are common after modular head-liner exchange in the setting of a failed MoM THA. Our study likely underestimates the frequency of complications and revisions because the followup period in this report was relatively short. Dislocation is the most common complication and elevated serum metal ion levels may be a predictor of dislocation. These findings are concerning and surgeons should be aware of the high complication risk associated with this procedure.Level Of Evidence: Level IV, therapeutic study. [ABSTRACT FROM AUTHOR]

Background: Magnetic resonance imaging (MRI) is a commonly utilized screening modality in patients with a metal-on-metal (MoM) total hip replacement. The prevalence of clinically important fluid collections may be overestimated since these collections have been reported to occur in asymptomatic patients with MoM and other bearing surfaces. The purpose of this study was to determine the frequency and types of MRI-documented adverse local tissue reactions in asymptomatic patients with a ceramic-on-polyethylene (CoP) total hip replacement.Methods: Forty-four patients (50 hips) with a minimum 2-year follow-up after total hip arthroplasty with CoP implants and a Harris hip score of >90 were enrolled in this study. The inclusion criteria were the absence of hip pain and the availability of appropriate follow-up radiographs. All patients underwent a metal artifact reduction sequence (MARS) MRI scan to determine the presence of fluid collections in asymptomatic patients with a CoP bearing surface.Results: Fluid collections were observed in 9 (18%) of 50 asymptomatic hips in this cohort. There were 5 hips with intracapsular synovitis, and 2 of these hips had a thickened synovium. Extra-articular fluid collections with direct intracapsular communication were identified in 4 additional hips. Two of these hips had a thickened synovium. No signs of osteolysis or evidence of adverse local tissue reactions were noted on radiographs at the most recent follow-up.Conclusions: This study revealed that fluid collections are not uncommon after total hip arthroplasty with CoP implants. Synovial thickening may be present and is more prevalent than has been reported in previous studies involving metal-on-polyethylene (MoP) bearing surfaces. The clinical importance and natural history of these findings remain unknown.Level Of Evidence: Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Total hip arthroplasty with ceramic-on-ceramic bearing surfaces has demonstrated low wear with excellent clinical outcomes. More recently, concerns have surfaced because of the presence of audible squeaking in some ceramic-on-ceramic THA patients. The incidence of this phenomenon has been low and has infrequently required reoperation. The exact etiology of squeaking remains unclear but is likely related to variations in surgical technique, patient selection, and implant design, particularly those designs that result in premature femoral neck-acetabular component rim impingement such as the presence of modular ceramic liner designs that are placed within a titanium encasement which has an extended rim. Hopefully, with continued improvements in design, materials, and component positioning, squeaking following ceramic-on-ceramic THA can be minimized. [ABSTRACT FROM AUTHOR]

Teleoperation is widely used for unmanned ground vehicle (UGV) navigation in military and civilian fields. However, the human operator has to limit speed to ensure the handling stability because of the low resolution of video, limited field of view and time delay in the control loop. In this paper, we propose a novel guidance point generation method that is well suited for human–machine cooperative UGV teleoperation in unstructured environments without a predefined goal position. The key novelty of this method is that the guidance points used for navigation can be generated with only the local perception information of the UGV. Firstly, the locally occupied grid map (OGM) was generated utilizing a probabilistic grid state description method, and converted into binary image to constructed the convex hull of obstacle area. Secondly, we proposed an improved thinning algorithm to extract skeletons of navigable regions from binary images, and find out the target skeleton related to the position of the UGV utilizing the k-nearest neighbor (kNN) algorithm. The target skeleton was reconstructed at the midline position of the navigable region using the decreasing gradient algorithm in order to obtain the appropriate skeleton end points for use as candidate guidance points. For visually presenting the driving trend of the UGV and convenient touch screen operation, we transformed guidance point selection into trajectory selection by generating the predicted trajectory correlative to candidate guidance points based on the differential equation of motion. Experimental results show that the proposed method significantly increases the speed of teleoperated UGV. [ABSTRACT FROM AUTHOR]

Aims: Of growing concern in arthroplasty is the emergence of atypical infections, particularly Cutibacterium (formerly Propionibacterium ) sp. infections. Currently, the dermal colonization rate of Cutibacterium about the hip is unknown. Therefore, the aim of this study was to investigate colonization rates of Cutibacterium sp. at locations approximating anterior and posterolateral approaches to the hip joint., Methods: For this non-randomized non-blinded study, 101 adult patients scheduled for hip or knee surgery were recruited. For each, four 3 mm dermal punch biopsies were collected after administration of anaesthesia, but prior to antibiotics. Prebiopsy skin preparation consisted of a standardized preoperative 2% chlorhexidine skin cleansing protocol and an additional 70% isopropyl alcohol mechanical skin scrub immediately prior to biopsy collection. Two skin samples 10 cm apart were collected from a location approximating a standard direct anterior skin incision, and two samples 10 cm apart were collected from a lateral skin incision (suitable for posterior, direct-lateral, or anterolateral approaches). Samples were cultured for two weeks using a protocol optimized for Cutibacterium ., Results: A total of 23 out of 404 cultures (collected from 101 patients) were positive for a microorganism, with a total of 22 patients having a positive culture (22%). Overall, 15 of the cultures in 14 patients were positive for Cutibacterium sp. (65%), of which Cutibacterium acnes comprised the majority (n = 13; 87%). Other isolated microorganisms include coagulase-negative Staphylococcus (n = 6), Clostridium (n = 1), and Corynebacterium (n = 1). Of all positive cultures, 15 were obtained from the anterior location (65%), of which seven (60%) were from the most proximal biopsy location. However, these findings were not statistically significant (anterior vs lateral, p = 0.076; proximal vs distal, p =0.238)., Conclusion: Approximately 14% (14/101) of the patients demonstrated a positive Cutibacterium colonization about the hip, the majority anteriorly. Given the high colonization rate of Cutibacterium , alternative skin preparations for total hip arthroplasty should be considered. Cite this article: Bone Joint J 2020;102-B(7 Supple B):52-56.

Background: The direct anterior approach (DAA) for total hip arthroplasty (THA) has gained recent popularity, with 1 purported benefit being access to intraoperative fluoroscopy. However, there are limited data demonstrating improved component position with the use of intraoperative fluoroscopy. The aim of this study is to compare radiographic implant positioning on 2 consecutive cohorts of patients undergoing DAA THA performed by 1 surgeon either utilizing intraoperative fluoroscopy or not. We hypothesized that there would be no relevant radiographic differences between the cohorts., Methods: Forty-two consecutive patients underwent DAA THA utilizing fluoroscopy (IFC), and 42 consecutive patients then underwent DAA THA without fluoroscopy (NFC). Using preoperative pelvis radiographs and 6-week postoperative pelvis radiographs, acetabular anteversion, inclination, femoral offset, and templated component sizes vs final intraoperatively selected sizes were recorded and compared between cohorts., Results: Acetabular inclination was 45.0° for IFC and 45.6° for NFC ( P  = .629). Femoral offset difference preoperatively and postoperatively was 0.8 mm for IFC and 1.3 mm for NFC ( P  = .734). Number of hips within the so-called safe zone was 32 for IFC and 33 for NFC ( P  = .794). These all demonstrated no significant difference between the cohorts. However, acetabular anteversion was 13.7° for IFC and 11.2° for NFC ( P  = .02)., Conclusions: In this limited series, the routine use of intraoperative fluoroscopy did not improve implant positioning or sizing. This may be surgeon-specific or due to the result of the use of acetabular landmarks to guide placement of the components without fluoroscopy., (© 2019 The Authors.)

Health care organizations must respond quickly to today's volatile and changing environment. This article describes how St. Michael's Hospital (acute care hospital) and the Drs. Paul and John Rekai Centre (long-term care facility) collaborated to use an innovative approach to address pressures of change affecting peritoneal dialysis (PD) care delivery for the elderly. The collaborative applied Galpin's (1996) nine-stage Change Management Model to implement the organizational change. Both organizations generated a shared vision to improve timely access to nursing homes for patients requiring both placement and ongoing peritoneal dialysis. They analyzed their current status and committed resources for the collaboration. Both organizations generated general and detailed recommendations for PD care delivery processes. A pilot was implemented and refinement of the collaboration occurred prior to formal roll out. This application of a change management model to establish organizational partnership may be of interest to those seeking to establish similar collaborations.

This study evaluated the efficacy of vacuum-assisted closure (VAC) for treatment of fasciotomy wounds for traumatic compartment syndrome. The authors reviewed the records of a consecutive series of 34 patients who had compartment syndrome of the leg requiring the standard two-incision release of all four compartments and received the application of VAC therapy until the time of definitive wound closure or coverage. A matched series of 34 consecutive antecedent patients with the same entry criteria, except for the use of the VAC, were also studied and served as a control group. The main parameter of interest was the time to "definitive closure" (delayed primary closure with sutures or skin graft coverage) of the wounds. Of the 68 wounds in 34 patients managed with VAC, the average time to definitive closure for both the lateral and the medial wounds was 6.7 days. For the 70 wounds in the 34 control patients, the average time to definitive closure was 16.1 days. This difference in time to wound closure between the VAC group and the non-VAC group was statistically significant (p < .05). Subatmospheric treatment for compartment syndrome of the leg after fasciotomy theoretically helps to speed the resolution of the swelling and tissue edema that are often components of this clinical entity. Experimental work has shown vacuum-assisted wound management to be effective in hastening the resolution of wound edema, enhancing local blood flow, promoting granulation tissue, and thwarting bacterial colonization. These factors may account for its utility in the management of fasciotomy wounds in the setting of compartment syndrome of the leg.

Objectives: The study evaluated the outcome of the treatment of patients who sustained high-energy, compression-type injuries of the distal radius., Design: The retrospective study evaluated the outcome of reduction and plating of the lunate facet in conjunction with standard external fixation., Setting: A Level I trauma center., Patients: Inclusion criteria for study participation included: 1) age between 18 and 65 years of age with no evidence of concomitant metabolic bone disease; and 2) a 3- or 4-part compression type fracture of the distal radius with residual displacement of the palmar lunate facet despite reduction of the dorsal cortex by the application of an external fixator., Intervention: Fractures were treated with palmar plating of the depressed lunate facet combined with dorsal external fixation., Main Outcome Measurements: Posttreatment evaluations consisted of measurements of range of motion, grip strength, radiographic evaluations, and completion of Disability of Arm, Shoulder, and Hand questionnaires., Results: Three months after surgery, 20 of 21 patients exhibited full range of motion at the MCP/PIP joints. At the 2-year follow-up, an average palmar tilt of +1.0 degrees, radial inclination of 24 degrees, radial length of 12 mm, ulnar variance of 0.5 mm, intra-articular gap of 0.1 mm, and intra-articular step-off of 0.3 mm was documented. Using the Garland and Werley rating system, results were rated as excellent or good for 18 wrists, fair for 2 wrists, and poor for 1 wrist. Mean Disability of Arm, Shoulder, and Hand functional scores and athletic scores improved at 6 months., Conclusions: Reduction and plating of the lunate facet in conjunction with standard external fixation permits: 1) visualization and reduction of the palmar lunate facet; and 2) reduction of palmar tilt to neutral tilt without significant radial shortening. This technique should be considered as an acceptable option in the treatment of high-energy fractures of the distal radius.