Survey of spiking in the mouse visual system reveals functional hierarchy.

The anatomy of the mammalian visual system, from the retina to the neocortex, is organized hierarchically1. However, direct observation of cellular-level functional interactions across this hierarchy is lacking due to the challenge of simultaneously recording activity across numerous regions. Here we describe a large, open dataset-part of the Allen Brain Observatory2-that surveys spiking from tens of thousands of units in six cortical and two thalamic regions in the brains of mice responding to a battery of visual stimuli. Using cross-correlation analysis, we reveal that the organization of inter-area functional connectivity during visual stimulation mirrors the anatomical hierarchy from the Allen Mouse Brain Connectivity Atlas3. We find that four classical hierarchical measures-response latency, receptive-field size, phase-locking to drifting gratings and response decay timescale-are all correlated with the hierarchy. Moreover, recordings obtained during a visual task reveal that the correlation between neural activity and behavioural choice also increases along the hierarchy. Our study provides a foundation for understanding coding and signal propagation across hierarchically organized cortical and thalamic visual areas.

Arthroscopic Rotator Cuff Repair Results in Improved Clinical Outcomes and Low Revision Rates at 10-Year Follow-Up: A Systematic Review.

PURPOSE: To study the literature to evaluate the functional outcomes, radiologic outcomes, and revision rates following arthroscopic rotator cuff repair (ARCR) at a minimum of 10-years follow-up. METHODS: Two independent reviewers performed a literature search of PubMed, Embase, and Scopus using the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Only studies reporting on outcomes of ARCR with a minimum 10-year follow-up were considered for inclusion. Patient demographics, satisfaction, and clinical, radiologic, and surgical outcomes were evaluated. RESULTS: Our search found 9 studies including 455 shoulders in 448 patients (51.6% male patients), with age at time of surgery ranging from 45 to 90 years met our inclusion criteria. Overall follow-up ranged from 10 to 18 years. At final follow-up, the ranges of American Shoulder & Elbow Surgeons, age- and sex-adjusted Constant-Morley, and University of California Los Angeles scores were reported in 5, 6, and 3 studies, respectively, as 79.4 to 93.2, 73.2 to 94, and 26.5 to 33, respectively. Of the included studies, satisfaction rates varied in 6 studies from 85.7% to 100% in the long-term. Additionally, the overall radiologic retear rate ranged from 9.5% to 63.2%. The overall surgical revision rates ranged in 6 studies from 3.8% to 15.4%, with from 0% to 6.7% requiring revision ARCR and from 1.0% to 3.6% requiring revision subacromial decompression in 6 and 2 studies, respectively, at minimum 10-years' follow-up. CONCLUSIONS: In this study, we found that ARCR results in high rates of patient satisfaction, satisfactory clinical outcomes with respect to patient-reported functional outcomes and range of motion, and low revision rates at minimum 10-years' follow-up. However, an overall 30% retear rate was observed in asymptomatic patients. LEVEL OF EVIDENCE: Level IV, systematic review of Level II-IV studies.

Consumer mobility and expenditure during the COVID-19 containments: Evidence from French transaction data.

This paper investigates the effects of the pandemic containment periods in France on individuals' movements, expenditure and adaptation to the shock, using billions of French bank card transactions measured before and during the COVID-19 pandemic. We measure not only the effect on consumer expenditure, but also on quantities directly related to the containment restrictions, such as consumer mobility, number of retailers visited, and inter-regional purchases. The results show large effects on these measures of consumers' movements, as well as on both online and offline measures of expenditure, particularly in the first containment period. We also find evidence that consumers adjusted rapidly during the first containment period, mitigating the effects of mobility restrictions via an increasing shift toward online purchasing, and that the nature of the adaptation differed for different types of purchase.

Rapid Increase in SARS-CoV-2 P.1 Lineage Leading to Codominance with B.1.1.7 Lineage, British Columbia, Canada, January-April 2021.

Several severe acute respiratory syndrome coronavirus 2 variants of concern (VOCs) emerged in late 2020; lineage B.1.1.7 initially dominated globally. However, lineages B.1.351 and P.1 represent potentially greater risk for transmission and immune escape. In British Columbia, Canada, B.1.1.7 and B.1.351 were first identified in December 2020 and P.1 in February 2021. We combined quantitative PCR and whole-genome sequencing to assess relative contribution of VOCs in nearly 67,000 infections during the first 16 weeks of 2021 in British Columbia. B.1.1.7 accounted for <10% of screened or sequenced specimens early on, increasing to >50% by week 8. P.1 accounted for <10% until week 10, increased rapidly to peak at week 12, and by week 13 codominated within 10% of rates of B.1.1.7. B.1.351 was a minority throughout. This rapid expansion of P.1 but suppression of B.1.351 expands our understanding of population-level VOC patterns and might provide clues to fitness determinants for emerging VOCs.

Long-term outcomes of radial head arthroplasty for radial head fractures-a systematic review at minimum 8-year follow-up.

BACKGROUND: The purpose of this study was to systematically review the literature to evaluate the functional outcomes, radiologic outcomes, and revision rates following radial head arthroplasty (RHA) at a minimum of 8 years follow-up. METHODS: Two independent reviewers performed a literature search using the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines using PubMed, Embase, and Web of Science databases. Only studies reporting on outcomes of RHA with a minimum of mean 8 years' follow-up were considered for inclusion. RESULTS: Our search found 10 studies including 432 elbows (51% males), with average age of 50 years (15-93) and mean follow-up of 117 months (98-145) met our inclusion criteria. At final follow-up, the mean Mayo Elbow Performance Score and Quick Disabilities of the Arm, Shoulder, and Hand questionnaire score were 83 (45-100) and 17 (0-63) respectively, and 86% of patients reported having no or minimal pain. The overall dislocation, subluxation, ulnar neuritis, and infection rates were 2%, 4%, 3%, and 3%, respectively. The rates of radiologic loosening, radiolucency, degenerative change, and heterotopic ossification were 9%, 46%, 27%, and 38%, respectively. The overall surgical revision rates were 20%, with 3%, 15%, and 5% requiring RHA implant revision, removal of metal or implants, and arthrolysis, respectively. CONCLUSION: Our systematic review established that RHA results in satisfactory clinical outcomes and modest complication and revision rates at long-term follow-up, despite high levels of radiologic degenerative changes over the same period.

The Operative Treatment of Ankle Fractures: A 10-Year Retrospective Study of 1529 Patients.

Ankle fractures are the second most common fracture of the lower limb and account for nearly 10% of all fractures. They range from simple to complex injuries and approximately 40% require surgical intervention. The aim of our study was to provide an up-to-date reference of the epidemiology, fracture, and fixation characteristics of operatively treated ankle fractures. We also sought to determine the number of patients undergoing further surgery through revision, implant removal, or ankle fusion. A retrospective observational study was conducted of 1529 consecutive patients that underwent operative intervention for an unstable ankle fracture between 2007 and 2017. Fractures of the distal tibia and pilon injuries were excluded. The mean age of patients was 41.8 years with 50.7% male. Unimalleolar fixation was performed in 60.1%, while bimalleolar and trimalleolar fixation was performed in 31.2% and 5%, respectively. Isolated syndesmotic fixation was performed in 3.8%. A posterior malleolus fracture was present in 28.6%, of which 31.6% underwent fixation. A further procedure was performed in 234 (15.3%) patients. Revision open reduction internal fixation was required in 1.4% and 0.8% underwent future ankle fusion. Treatment of ankle fractures makes up a sizeable part of orthopedic trauma practice with more than 1 in 7 patients requiring a second procedure. More complex fractures were predominantly seen in older females, while patients who suffered trimalleolar fractures have an increased likelihood of requiring future ankle fusion or revision. Despite this the rate of ankle fusion was <1%.

Charge-Shift Bonding: A New and Unique Form of Bonding.

Charge-shift bonds (CSBs) constitute a new class of bonds different than covalent/polar-covalent and ionic bonds. Bonding in CSBs does not arise from either the covalent or the ionic structures of the bond, but rather from the resonance interaction between the structures. This Essay describes the reasons why the CSB family was overlooked by valence-bond pioneers and then demonstrates that the unique status of CSBs is not theory-dependent. Thus, valence bond (VB), molecular orbital (MO), and energy decomposition analysis (EDA), as well as a variety of electron density theories all show the distinction of CSBs vis-à-vis covalent and ionic bonds. Furthermore, the covalent-ionic resonance energy can be quantified from experiment, and hence has the same essential status as resonance energies of organic molecules, e.g., benzene. The Essay ends by arguing that CSBs are a distinct family of bonding, with a potential to bring about a Renaissance in the mental map of the chemical bond, and to contribute to productive chemical diversity.

A comparison of the analgesic efficacy of local infiltration analgesia vs. intrathecal morphine after total knee replacement: A randomised controlled trial.

BACKGROUND: Local infiltration analgesia (LIA) is an effective pain management technique following total knee arthroplasty (TKA). OBJECTIVE: To investigate if LIA provides better analgesia for patients undergoing unilateral TKA than intrathecal morphine. DESIGN: Randomised controlled trial. SETTING: Single tertiary referral centre. PATIENTS: Consecutive American Society of Anesthesiologists Physical Status I to III patients scheduled to undergo unilateral TKA were randomised to two groups. INTERVENTION: The control group received spinal anaesthesia with intrathecal bupivacaine and preservative-free morphine 0.3 mg. The intervention group received opioid-free spinal anaesthesia with bupivacaine, followed by intra-operative infiltration of the knee with levobupivacaine 2 mg kg and adrenaline 0.5 mg diluted to a volume of 100 ml with 0.9% saline. An intra-articular catheter was placed during surgery and used to give a bolus of 15 ml of levobupivacaine 0.5% on the morning of the first postoperative day. MAIN OUTCOME MEASURES: Visual analogue scale (VAS) scores for pain were assessed repeatedly for 48 h postoperatively, at rest and on passive knee flexion to 30°. The primary outcome was VAS scores for pain at rest and on movement at 24 postoperative hours. Secondary outcomes were VAS scores at rest and on movement at 2, 6, 12 and 48 postoperative hours, opioid consumption, degree of active flexion of operative knee achieved in the first 48 h and the incidence of opioid-related side effects. RESULTS: Forty three patients completed the study. Mean (± SD) VAS scores for pain at 24 h were lower in the intervention group than the control group at rest; 16.43 (± 20.3) vs. 37.2 (± 33.6), (P = 0.029). VAS scores for pain at 24 h on movement were also lower in the intervention group vs. the control group; 39.1 (± 22.8) vs. 57.0 (± 30.9), (P = 0.037). VAS scores were also lower on movement; 25.9 (± 16.8) vs. 40.5 (± 24.0), (P = 0.028) at 48 h. CONCLUSION: We conclude that LIA conferred superior analgesia compared with intrathecal morphine 0.3 mg at 24 and 48 h following TKA. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT01312415.

Telesurveillance: Exploring the Use of Mobile Phone Imaging in the Follow-Up of Orthopedic Patients with Hand Trauma.

Background: Intra-articular phalangeal fractures involving the proximal interphalangeal joint (PIPJ) are notoriously difficult injuries to treat and often require regular follow-up to assess progress, guide treatment, and determine outcomes. Some patients often have to travel long distances for follow-up care. The aim of our study was to assess the clinical outcomes of intra-articular fractures of the PIPJ through use of clinical pictures sent through a mobile phone.Methods: A retrospective study was conducted of a consecutive group of patients treated with a static external fixator (Micro Hoffman-2 Stryker®) between 2006 and 2016 for an intra-articular fracture of the PIPJ. Range of motion (ROM) at the PIPJ was assessed through clinical pictures taken on a mobile phone.Results: Clinical images were received from 15 patients with a mean age of 31.9 years (range 15-51), of which 73.3% of patients were male. Mean length of follow-up was 39 months. Around 73.3% of injuries occurred while playing a sport. Mean PIPJ ROM assessed through the clinical images was 67°.Conclusion: Our study shows that it was possible to assess ROM at the PIPJ through the use of clinical pictures taken by mobile phone. The use of mobile phones to take images provided a simple, easy, and convenient means of assessing outcome in this cohort of patients. We describe a method of follow-up that may have a greater role in the future.

The burden of hardware removal in ankle fractures: How common is it, why do we do it and what is the cost? A ten-year review.

BACKGROUND: Ankle fractures account for 9% of all fractures and 40% require surgical management. The ankle is the most common site of hardware removal. The purpose of our study was to investigate the incidence, indication and economic cost associated with removal of hardware from the ankle. METHODS: We conducted a ten-year retrospective review of 1482 patients treated by open reduction internal fixation for an unstable ankle fracture. Skeletally immature patients were excluded. Data collected was cross referenced from patient medical records, the radiological and electronic patient database. The casemix and hospital inpatient enquiry system (HIPE) were used to calculate costs. RESULTS: The mean age was 39.9 years with 53.6% male. 185 patients (12.5%) underwent hardware removal with unplanned removal performed in 6% of cases. The average cost of removal was €1113. CONCLUSION: Removal of hardware continues to be a common operation with significant costs to all involved. More than one in 10 patients underwent future removal of hardware. LEVEL OF EVIDENCE: Level 3.

Hydrogen bonding from a valence bond theory perspective: the role of covalency.

A valence bond theory based method has been developed to decompose hydrogen bond energies into contributions from geometry, electrostatics, polarization and charge transfer. This decomposition method has been carried out for F-HFH, F-HOH2, F-HNH3, HO-HOH2, HO-HNH3, and H2N-HNH3. Localized valence bond self-consistent field (L-VBSCF) and localized breathing orbital valence bond (L-BOVB) calculations were performed at the PBEPBE/aug-cc-pVDZ optimized geometries. It is shown that inclusion of valence bond structures that explicitly include charge transfer account for at least 32% (likely over half) of the hydrogen bond energy of all systems studied, indicating the dominant role of covalency. This is in agreement with calculated bond lengths, geometry deformation energies, and polarization energies. Electrostatic effects were found to play only a minor role in contrast to some widely held ideas regarding the nature of hydrogen bonding.

Charge-Shift Corrected Electronegativities and the Effect of Bond Polarity and Substituents on Covalent-Ionic Resonance Energy.

Bond dissociation energies and resonance energies for HnA-BHm molecules (A, B = H, C, N, O, F, Cl, Li, and Na) have been determined in order to re-evaluate the concept of electronegativity in the context of modern valence bond theory. Following Pauling's original scheme and using the rigorous definition of the covalent-ionic resonance energy provided by the breathing orbital valence bond method, we have derived a charge-shift corrected electronegativity scale for H, C, N, O, F, Cl, Li, and Na. Atomic charge shift character is defined using a similar approach resulting in values of 0.42, 1.06, 1.43, 1.62, 1.64, 1.44, 0.46, and 0.34 for H, C, N, O, F, Cl, Li, and Na, respectively. The charge-shift corrected electronegativity values presented herein follow the same general trends as Pauling's original values with the exception of Li having a smaller value than Na (1.57 and 1.91 for Li and Na respectively). The resonance energy is then broken down into components derived from the atomic charge shift character and polarization effects. It is then shown that most of the resonance energy in the charge-shift bonds H-F, H3C-F, and Li-CH3 and borderline charge-shift H-OH is associated with polarity rather than the intrinsic atomic charge-shift character of the bonding species. This suggests a rebranding of these bonds as "polar charge-shift" rather than simply "charge-shift". Lastly, using a similar breakdown method, it is shown that the small effect the substituents -CH3, -NH2, -OH, and -F have on the resonance energy (<10%) is mostly due to changes in the charge-shift character of the bonding atom.

Recording Adverse Events Following Joint Arthroplasty: Financial Implications and Validation of an Adverse Event Assessment Form.

BACKGROUND: In Ireland, funding of joint arthroplasty procedures has moved to a pay-by-results national tariff system. Typically, adverse clinical events are recorded via retrospective chart-abstraction methods by administrative staff. Missed or undocumented events not only affect the quality of patient care but also may unrealistically skew budgetary decisions that impact fiscal viability of the service. Accurate recording confers clinical benefits and financial transparency. The aim of this study was to compare a prospectively implemented adverse events form with the current national retrospective chart-abstraction method in terms of pay-by-results financial implications. METHODS: An adverse events form adapted from a similar validated model was used to prospectively record complications in 51 patients undergoing total hip or knee arthroplasties. Results were compared with the same cohort using an existing data abstraction method. Both data sets were coded in accordance with current standards for case funding. RESULTS: Overall, 114 events were recorded during the study through prospective charting of adverse events, compared with 15 events documented by customary method (a significant discrepancy). Wound drainage (15.8%) was the most common complication, followed by anemia (7.9%), lower respiratory tract infections (7.9%), and cardiac events (7%). A total of €61,956 ($67,778) in missed funding was calculated as a result. CONCLUSION: This pilot study demonstrates the ability to improve capture of adverse events through use of a well-designed assessment form. Proper perioperative data handling is a critical aspect of financial subsidies, enabling optimal allocation of funds.

Obtaining local bone graft for Evans calcaneal osteotomy in pes planovalgus deformity correction.

Lateral column lengthening osteotomy is very useful surgical technique in treating stage II of pes planovalgus deformity of the foot. Either autograft from the iliac crest or allograft can be used for this purpose. In our technique we describe a novel method of obtaining bone graft locally from the calcaneus and therefore avoiding complications and morbidity associated with iliac crest graft.

Complete tendon Achilles rupture following injection of Aethoxysklerol (polidocanol) for the treatment of chronic Achilles tendinopathy.

Achilles tendinopathy can be a chronic disabling condition affecting both athletic and sedentary patients. Multiple new treatment approaches have developed, including shock wave therapy and various types of injection. One of the novel treatment methods used is the injection of Aethoxysklerol or polidocanol, a sclerosing substance injected under ultrasound guidance targeting areas of neovascularisation. We report the case of a 78-year-old lady who suffered a complete Achilles tendon rupture following injection of Aethoxysklerol. This is the first case of Achilles tendon rupture following Aethoxysklerol injection in isolation to our knowledge in the literature and the first published complication of this treatment.

Effect of Lone Pairs on Molecular Resonance Energy.

In an effort to understand the theoretical parameters of charge-shift bonding, computational experiments have been designed to elucidate the factors effecting molecular resonance energy. Valence bond theory calculations have been used to calculate resonance energies of homonuclear bonds in the series [HnX-XHn]Z, where n = 0-3 and Z = 2n - 6, 2n - 4, 2n - 2, and 2n for X = C, N, O, and F, respectively. It is shown that the resonance energy decreases as the number of lone pairs increases. Calculated orbital contraction coefficients show that this unexpected result is due to the dominance of orbital size over the lone-pair effect. These results are irrespective of the HXX bond angles. It is also shown that the resonance energy increases with decreasing HXX bond angles due to the increase in p character in the bonding orbital.

Long-term clinical outcomes of arthroscopic supraspinatus tendon repair using the single anchor tension band technique - Minimum 5-years follow-up.

Background: The primary aim of this study was to assess the long-term patient reported outcomes of arthroscopic rotator cuff tear (ARCR) using a single anchor tension band (TB) technique for small and medium supraspinatus tears at minimum 5-years follow-up. Methods: A retrospective cohort study of consecutive ARCRs of small and medium supraspinatus tears using a knotless single anchor TB technique with minimum 5-year follow-up was carried out. Outcomes of interest included: range of motion (ROM) on examination under anaesthesia (EUA), visual analogue scale (VAS), American Shoulder and Elbow Surgeons (ASES) scores, Oxford Shoulder Score (OSS) and Short-Form (SF-12). Results: From 243 consecutive ARCR procedures, 82 patients with a mean age of 55 ± 9.5 years met the inclusion criteria at 6.7 ± 1.5 years follow-up. There were significant improvements in VAS (5.5 ± 2.2 vs. 0.7 ± 1.5), ASES (47.6 ± 16.8 vs. 92.8 ± 13.0), OSS (31.3 ± 7.2 vs. 45.3 ± 3.5) and SF-12 (37.6 ± 7.6 vs. 50.3 ± 7.7) post-operatively (all p < 0.001). Conclusions: The single anchor TB ARCR technique has excellent patient reported outcomes at a minimum of 5 years and is suitable for supraspinatus tears smaller than 20 mm in the sagittal plane. Level of evidence: Level IV; Consecutive Case Series.

Inflammatory pseudotumor causing deep vein thrombosis after metal-on-metal hip resurfacing arthroplasty.

Metal-on-metal hip resurfacings have recently been associated with a variety of complications resulting from adverse reaction to metal debris. We report a case of extensive soft tissue necrosis associated with a huge pelvic mass causing extensive deep vein thrombosis of the lower limb secondary to mechanical compression of the iliac vein. This is a rare and unusual cause of deep vein thrombosis after metal-on-metal hip resurfacing arthroplasty.

Biomechanical analysis of three techniques of suspensionplasty after trapeziectomy: a cadaveric study.

The aim of the present cadaveric study was to assess resistance to first metacarpal subsidence of three techniques of suspensionplasty after trapeziectomy. In total, 18 forearms (mean age 60 years [range 20-89]) were used with six specimens per surgical technique: palmar oblique ligament reconstruction with tendon interposition (LRTI), abductor pollicis longus (APL) suspensionplasty, or suture suspensionplasty. There was no significant difference in mean trapezial space height after trapeziectomy and suspensionplasty compared to the preoperative trapezial height. However, after simulation of physiological lateral pinch, there was a significant (p < 0.05) difference in mean trapezial space height between the APL suspensionplasty and the suture suspensionplasty compared to the LRTI group. After axial loading, there was significantly greater metacarpal subsidence in the LRTI group compared to the APL and suture suspensionplasty groups but no statistically significant difference between the suture suspensionplasty and the APL suspensionplasty groups.Level of evidence: V.