Goal conceptualization has distinct effects on spatial and temporal bimanual coordination after left- and right- hemisphere stroke.

Perception of task goal influences motor performance and coordination. In bimanual actions, it is unclear how one's perception of task goals influences bimanual coordination and performance in individuals with unilateral stroke. We characterized inter-limb coordination differences in individuals with chronic right- and left-hemisphere damaged (RCVA: n = 24, LCVA: n = 24) stroke and age-matched neurotypical controls (n = 24) as they completed bimanual reaching tasks under distinct goal conditions. In the dual-goal condition, participants reached to move two virtual bricks (cursors) assigned to each hand toward independent targets. In the common-goal condition, they moved a central common virtual brick representing both hands to a single, central target. Spatial and temporal coordination (cross-correlation coefficients of hand velocity and their time-lag), the redundant axis deviations (the hand deviations in the axis orthogonal to the axis along the cursor-target direction), and the contribution ratio of the paretic hand were measured. Compared to the dual-goal condition, reaching actions to the common-goal demonstrated better spatial bimanual coordination in all three participant groups. Temporal coordination was better during common-goal than dual-goal actions only for the LCVA group. Additionally, and novel to this field, sex, as a biological variable, differently influenced movement time and redundant axis deviation in participants with stroke under the common-goal condition. Specifically, female stroke survivors showed larger movements in the redundant axes and, consequently, longer movement times, which was more prominent in the LCVA group. Our results indicate that perception of task goals influences bimanual coordination, with common goal improving spatial coordination in neurotypical individuals and individuals with unilateral stroke and providing additional advantage for temporal coordination in those with LCVA. Sex influences bimanual performance in stroke survivors and needs to be considered in future investigations.

Vision-controlled jetting for composite systems and robots.

Recreating complex structures and functions of natural organisms in a synthetic form is a long-standing goal for humanity1. The aim is to create actuated systems with high spatial resolutions and complex material arrangements that range from elastic to rigid. Traditional manufacturing processes struggle to fabricate such complex systems2. It remains an open challenge to fabricate functional systems automatically and quickly with a wide range of elastic properties, resolutions, and integrated actuation and sensing channels2,3. We propose an inkjet deposition process called vision-controlled jetting that can create complex systems and robots. Hereby, a scanning system captures the three-dimensional print geometry and enables a digital feedback loop, which eliminates the need for mechanical planarizers. This contactless process allows us to use continuously curing chemistries and, therefore, print a broader range of material families and elastic moduli. The advances in material properties are characterized by standardized tests comparing our printed materials to the state-of-the-art. We directly fabricated a wide range of complex high-resolution composite systems and robots: tendon-driven hands, pneumatically actuated walking manipulators, pumps that mimic a heart and metamaterial structures. Our approach provides an automated, scalable, high-throughput process to manufacture high-resolution, functional multimaterial systems.

Oral food challenge outcomes in children and adolescents in a tertiary centre: A 5-year experience.

AIM: Oral food challenges (OFC) are an important tool in the assessment of food allergy. We sought to identify factors available at initial assessment visit which were associated with successful outcome or challenge failure in Australian children. METHODS: We conducted a retrospective review of all paediatric patients who underwent OFC in our allergy service over a 5-year period. Clinical data comprising patient demographics, co-morbidities, skin prick test (SPT) results, nature of previous reactions, elapsed time since previous reactions and outcome at OFC were recorded. RESULTS: Four hundred and fifty-six OFCs were conducted, with 56 cases (12.3%) resulting in a reaction. Likelihood of reaction at OFC was significantly increased for patients with atopic dermatitis (odds ratio 1.99). When stratified by food substance, atopic dermatitis had the strongest association with reaction within the peanut group (odds ratio 3.2), and no association was demonstrated for soy or prawn. Increasing SPT wheal size (P < 0.001) and previous history of anaphylaxis to the challenge food (P < 0.001) correlated with failure at OFC. A low-risk group was identified, of patients with no clear history of prior reaction to the challenge food, and SPT result <3 mm. CONCLUSIONS: Factors identified at assessment visit which correlated with reaction at OFC are atopic dermatitis, prior history of anaphylaxis, and increasing SPT wheal size. Domiciliary OFC could be considered in a select low-risk group of patients undergoing food challenge. This study was performed at a single centre with limited sample size, further large-scale and multicentre study verification of our data will provide more accurate representation of the Australian demographic.

Bimanual coordination during reach-to-grasp actions is sensitive to task goal with distinctions between left- and right-hemispheric stroke.

The perceptual feature of a task such as how a task goal is perceived influences performance and coordination of bimanual actions in neurotypical adults. To assess how bimanual task goal modifies paretic and non-paretic arm performance and bimanual coordination in individuals with stroke affecting left and right hemispheres, 30 participants with hemispheric stroke (15 right-hemisphere damage-RHD); 15 left-hemisphere damage-LHD) and 10 age-matched controls performed reach-to-grasp and pick-up actions under bimanual common-goal (i.e., two physically coupled dowels), bimanual independent-goal (two physically uncoupled dowels), and unimanual conditions. Reach-to-grasp time and peak grasp aperture indexed motor performance, while time lags between peak reach velocities, peak grasp apertures, and peak pick-up velocities of the two hands characterized reach, grasp, and pick-up coordination, respectively. Compared to unimanual actions, bimanual actions significantly slowed non-paretic arm speed to match paretic arm speed, thus affording no benefit to paretic arm performance. Detriments in non-paretic arm performance during bimanual actions was more pronounced in the RHD group. Under common-goal conditions, movements were faster with smaller peak grasp apertures compared to independent-goal conditions for all groups. Compared to controls, individuals with stroke demonstrated poor grasp and pick-up coordination. Of the patient groups, patients with LHD showed more pronounced deficits in grasp coordination between hands. Finally, grasp coordination deficits related to paretic arm motor deficits (upper extremity Fugl-Meyer score) for LHD group, and to Trail-Making Test performance for RHD group. Findings suggest that task goal and distinct clinical deficits influence bimanual performance and coordination in patients with left- and right-hemispheric stroke.

Longitudinal Analysis of SARS-CoV-2 Vaccine Breakthrough Infections Reveals Limited Infectious Virus Shedding and Restricted Tissue Distribution.

Background: The global effort to vaccinate people against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during an ongoing pandemic has raised questions about how vaccine breakthrough infections compare with infections in immunologically naive individuals and the potential for vaccinated individuals to transmit the virus. Methods: We examined viral dynamics and infectious virus shedding through daily longitudinal sampling in 23 adults infected with SARS-CoV-2 at varying stages of vaccination, including 6 fully vaccinated individuals. Results: The durations of both infectious virus shedding and symptoms were significantly reduced in vaccinated individuals compared with unvaccinated individuals. We also observed that breakthrough infections are associated with strong tissue compartmentalization and are only detectable in saliva in some cases. Conclusions: Vaccination shortens the duration of time of high transmission potential, minimizes symptom duration, and may restrict tissue dissemination.

Acute compartment syndrome of the thigh in a body builder following open reduction and internal fixation for proximal femur fracture.

Acute compartment syndrome (ACS) of the thigh following femoral fracture has been rarely reported in previous literature. This condition must be diagnosed quickly to prevent the affected limb becoming ischaemic. We document the management of ACS of the thigh in a healthy male patient who suffered a proximal femur fracture following a high-speed road traffic accident. Early identification of characteristic clinical signs allowed for a diagnosis of ACS to be made and then managed with an emergency fasciotomy. The patient is a bodybuilder with an exceptionally large muscle mass. This made ACS more difficult to identify and wound closure a complex process over a period of 13 days. We aimed to highlight the importance of maintaining a high index of suspicion for ACS following traumatic injuries, recognising that ACS in larger patients can be mistaken for an increased analgesia requirement and closing fasciotomies slowly using mass tension sutures.

Medium-term mortality after hip fractures and COVID-19: A prospective multi-centre UK study.

PURPOSE: The COVID-19 pandemic has caused 1.4 million deaths globally and is associated with a 3-4 times increase in 30-day mortality after a fragility hip fracture with concurrent COVID-19 infection. Typically, death from COVID-19 infection occurs between 15 and 22 days after the onset of symptoms, but this period can extend up to 8 weeks. This study aimed to assess the impact of concurrent COVID-19 infection on 120-day mortality after a fragility hip fracture. METHODS: A multi-centre prospective study across 10 hospitals treating 8% of the annual burden of hip fractures in England between 1st March and 30th April, 2020 was performed. Patients whose surgical treatment was payable through the National Health Service Best Practice Tariff mechanism for "fragility hip fractures" were included in the study. Patients' 120-day mortality was assessed relative to their peri-operative COVID-19 status. Statistical analysis was performed using SPSS version 27. RESULTS: A total of 746 patients were included in this study, of which 87 (11.7%) were COVID-19 positive. Mortality rates at 30- and 120-day were significantly higher for COVID-19 positive patients relative to COVID-19 negative patients (p < 0.001). However, mortality rates between 31 and 120-day were not significantly different (p = 0.107), 16.1% and 9.4% respectively for COVID-19 positive and negative patients, odds ratio 1.855 (95% CI 0.865-3.978). CONCLUSION: Hip fracture patients with concurrent COVID-19 infection, provided that they are alive at day-31 after injury, have no significant difference in 120-day mortality. Despite the growing awareness and concern of "long-COVID" and its widespread prevalence, this does not appear to increase medium-term mortality rates after a hip fracture.

Longitudinal analysis of SARS-CoV-2 vaccine breakthrough infections reveal limited infectious virus shedding and restricted tissue distribution.

The global effort to vaccinate people against SARS-CoV-2 in the midst of an ongoing pandemic has raised questions about the nature of vaccine breakthrough infections and the potential for vaccinated individuals to transmit the virus. These questions have become even more urgent as new variants of concern with enhanced transmissibility, such as Delta, continue to emerge. To shed light on how vaccine breakthrough infections compare with infections in immunologically naive individuals, we examined viral dynamics and infectious virus shedding through daily longitudinal sampling in a small cohort of adults infected with SARS-CoV-2 at varying stages of vaccination. The durations of both infectious virus shedding and symptoms were significantly reduced in vaccinated individuals compared with unvaccinated individuals. We also observed that breakthrough infections are associated with strong tissue compartmentalization and are only detectable in saliva in some cases. These data indicate that vaccination shortens the duration of time of high transmission potential, minimizes symptom duration, and may restrict tissue dissemination.

Bankart Repair Versus Latarjet Procedure for Recurrent Anterior Shoulder Instability: A Systematic Review and Meta-analysis of 3275 Shoulders.

BACKGROUND: Little consensus is available regarding the standard treatment for recurrent anterior instability of the shoulder. Typically, treatment selection has been based on training and tradition rather than the available evidence. PURPOSE: This study aimed to compare the clinical outcomes between arthroscopic Bankart procedure and the Latarjet procedure in the treatment of recurrent anterior shoulder instability with emphasis on follow-up time. STUDY DESIGN: Systematic review and meta-analysis. METHODS: We searched PubMed, Cochrane Central Register of Controlled Trials, Scopus, Ovid, and Web of Science up to January 2018 and included studies that compared arthroscopic Bankart versus Latarjet for treatment of anterior shoulder instability. Continuous data, such as operative time and patient-reported outcomes, were pooled as mean differences (MDs), whereas dichotomous data, such as recurrence, revision, redislocation, arthropathy, infection, and hematoma, were pooled as risk ratios (RRs), with 95% CIs. RESULTS: Pooling data from 7 cohort studies (3275 patients) showed that arthroscopic Bankart was associated with a higher risk of redislocation (RR, 2.74; 95% CI, 1.48-5.06; P = .03), a higher risk of recurrence (RR, 2.87; 95% CI, 1.91-4.30; P < .0001), and a lower risk of infection (RR, 0.16; 95% CI, 0.06-0.43; P = .0002) compared with Latarjet, while the effect size did not favor arthroscopic Bankart or Latarjet in terms of Rowe score (MD, 0.22; 95% CI, -5.64 to 6.08; P = .94), revision (RR, 0.34; 95% CI, 0.08-1.39; P = .13), and hematoma (RR, 0.20; 95% CI, 0.03-1.19; P = .07). The effect estimate showed a pronounced advantage for Latarjet from 6 to 10 years postoperatively in terms of recurrence and redislocation (RR, 3.00; 95% CI, 1.98-4.56 and RR, 2.85; 95% CI, 1.51-5.38, respectively). CONCLUSION: Our results showed that Latarjet had less risk of recurrence and redislocation with longer follow-up time. Both procedures were comparable in terms of Rowe score, the need for revision, and postoperative hematoma formation, whereas Bankart repair was associated with a lower risk of infection.

Titanium Elastic Nails Versus Spica Cast in Pediatric Femoral Shaft Fractures: A Systematic Review and Meta-analysis of 1012 Patients.

BACKGROUND: There is a general consensus on the management of femoral fractures in children younger than two years and adolescents older than sixteen years. The best treatment for patients younger than sixteen years of age is still debatable. Titanium Elastic Nails (TEN), is widely used with some evidence, nonetheless, we undertook a systematic meta-analysis to assess the efficacy of TEN compared to Spica cast for the management of femoral shaft fracture in children aged between 2 to 16 years old. METHODS: A computer literature search of PubMed, Scopus, Web of Science, CINAHL and Cochrane Central was conducted using relevant keywords. We included clinical trials and observational studies that compared TEN versus Spica cast; Records were screened for eligible studies and data were extracted and synthesized using Review Manager version 5.3 for Windows. Our search found 573 unique articles. After screening the abstract and relevant full text, 12 studies with a total of 1012 patients were suitable for the final analysis. RESULTS: In terms terms of union (in weeks), the reported effect sizes favoured the TEN group in two included studies only. Moreover, the overall standardized mean difference in sagittal (SMD -0.48, 95% CI [-0.70 to -0.26], P<0.001) and coronal angulations (SMD -0.66, 95% CI [-1.00 to -0.31], P<0.001) favored TEN fixation in management of femoral fractures younger than 16 years. The reported length of hospital stay was not consistent across studies. The overall risk ratio of malalignment (RR=0.39, 95% CI [0.27 to 0.57], P<0.001) favored the TEN as well as walking independently. Based on our analysis, TEN treatment is superior to traction and hip spica for femoral fractures in patients younger than 16 years old. CONCLUSION: Based on our analysis we recommend the use of TEN fixation in management of pediatric femoral fractures in patients younger than 16 years.

The Dislocated Hip Hemiarthroplasty: Current Concepts of Etiological factors and Management.

BACKGROUND: Hip hemiarthroplasty (HA) following an intracapsular neck of femur fracture is an increasingly common procedure as a result of an ageing population. Patients are often frail and so morbidity and mortality figures are significant. As a result the National Institute for Health and Clinical Excellence (NICE) has formulated guidelines and a Best Practice Tariff (BPT) in an attempt to improve the care of such patients. Dislocation following HA is a potentially devastating complication with a reported incidence ranging from 1 to 15%. Multiple causative factors have been cited and studied in an effort to reduce the incidence of this complication which has a high rate of recurrence following the first episode and is associated with a high mortality rate and significant financial burden on the health economy. This paper reviews the available literature in an effort to identify the most pertinent factors affecting dislocation rates and thus reduce the incidence of this serious complication. METHODS: A comprehensive review of the literature was performed using the search engine PubMed with the keywords 'hip', 'hemiarthroplasty' and 'dislocation'. Two hundred and forty three articles were identified and assessed by the 3 authors independently. Data from fifty-two articles pertinent to the review on hemiarthroplasty dislocation epidemiology, risk factors and management were extracted in a standardised fashion. RESULTS: Following review of the papers multiple causative factors relating to HA dislocation were identified and grouped into 4 broad categories for analysis. The factors with the strongest correlation with dislocation included patient cognition, previous failed surgery, delay to surgery, surgical approach and femoral offset. CONCLUSION: Hip hemiarthroplasty remains the gold standard for elderly patients with intracapsular neck of femur fractures. In each individual case the factors most strongly associated with postoperative dislocation should be recognised. Delays to surgery should be minimised and the posterior approach avoided. In addition to good surgical technique, particular attention should be paid to restoring the patient's native femoral offset and post operatively those with cognitive impairment should be closely monitored.

Decision Making in the Management of Extracapsular Fractures of the Proximal Femur - is the Dynamic Hip Screw the Prevailing Gold Standard?

Currently, approximately half of all hip fractures are extracapsular, with an incidence as high as 50 in 100,000 in some countries. The common classification systems fail to explain the logistics of fracture classification and whether they all behave in the same manner. The Muller AO classification system is a useful platform to delineate stable and unstable fractures. The Dynamic hip screw (DHS) however, has remained the 'gold standard' implant of choice for application in all extracapsular fractures. The DHS relies on the integrity and strength of the lateral femoral wall as well as the postero-medial fragment. An analysis of several studies indicates significant improvements in design and techniques to ensure a better outcome with intramedullary nails. This article reviews the historical trends that helped to evolve the DHS implant as well as discussing if the surgeon should remain content with this implant. We suggest that the gold standard surgical management of extracapsular fractures can, and should, evolve.

Comminuted supracondylar femoral fractures: a biomechanical analysis comparing the stability of medial versus lateral plating in axial loading.

The aim of this study was to compare the biomechanical properties of medial and lateral plating of a medially comminuted supracondylar femoral fracture. A supracondylar femoral fracture model comparing two fixation methods was tested cyclically in axial loading. One-centimetre supracondylar gap osteotomies were created in six synthetic femurs approximately 6 cm proximal to the knee joint. There were two constructs investigated: group 1 and group 2 were stabilized with an 8-hole LC-DCP, medially and laterally, respectively. Both construct groups were axially loaded. Global displacement (total length), wedge displacement, bending moment and strain were measured. Medial plating showed a significantly decreased displacement, bending moment and strain at the fracture site in axial loading. Medial plating of a comminuted supracondylar femur fracture is more stable than lateral plating.

Patient functional outcomes with trapeziectomy alone versus trapeziectomy with TightRope(®).

PURPOSE OF THE STUDY: We assess whether patient functional outcomes with the use of a tightrope in conjunction with trapeziectomy are better than traditional trapeziectomy alone. METHODS: Retrospective study of 56 trapeziectomies in 53 patients; 26 trapeziectomies alone without additional procedures, and 30 trapeziectomies performed in conjunction with tightrope suspensionplasty. All patients were scored using Quick DASH, Patient-Rated Wrist Evaluation and Nelson base of thumb arthritis scores pre- and post-operatively. RESULTS: Significant improvements were seen with both operations using all three scoring systems. However, there was no statistically significant difference in post-operative scores between the two operations. STUDY DESIGN: Retrospective comparative study. LEVEL OF EVIDENCE: III.