Sport-related major trauma incidence in young people and adults in England and Wales: a national registry-based study.

OBJECTIVES: Data on sport and physical activity (PA) injury risk can guide intervention and prevention efforts. However, there are limited national-level data, and no estimates for England or Wales. This study sought to estimate sport and PA-related major trauma incidence in England and Wales. METHODS: Nationwide, hospital registry-based cohort study between January 2012 and December 2017. Following Trauma Audit and Research Network Registry Research Committee approval, data were extracted in April 2018 for people ≥16 years of age, admitted following sport or PA-related injury in England and Wales. The population-based Active Lives Survey was used to estimate national sport and PA participation (ie, running, cycling, fitness activities). The cumulative injury incidence rate was estimated for each activity. Injury severity was described by Injury Severity Score (ISS) >15. RESULTS: 11 702 trauma incidents occurred (mean age 41.2±16.2 years, 59.0% male), with an ISS >15 for 28.0% of cases, and 1.3% were fatal. The overall annual injury incidence rate was 5.40 injuries per 100 000 participants. The incidence rate was higher in men (6.44 per 100 000) than women (3.34 per 100 000), and for sporting activities (9.88 per 100 000) than cycling (2.81 per 100 000), fitness (0.21 per 100 000) or walking (0.03 per 100 000). The highest annual incidence rate activities were motorsports (532.31 per 100 000), equestrian (235.28 per 100 000) and gliding (190.81 per 100 000). CONCLUSION: Injury incidence was higher in motorsports, equestrian activity and gliding. Targeted prevention in high-risk activities may reduce admissions and their associated burden, facilitating safer sport and PA participation.

Subacromial balloon spacer for irreparable rotator cuff tears of the shoulder (START:REACTS): a group-sequential, double-blind, multicentre randomised controlled trial.

BACKGROUND: New surgical procedures can expose patients to harm and should be carefully evaluated before widespread use. The InSpace balloon (Stryker, USA) is an innovative surgical device used to treat people with rotator cuff tears that cannot be repaired. We aimed to determine the effectiveness of the InSpace balloon for people with irreparable rotator cuff tears. METHODS: We conducted a double-blind, group-sequential, adaptive randomised controlled trial in 24 hospitals in the UK, comparing arthroscopic debridement of the subacromial space with biceps tenotomy (debridement only group) with the same procedure but including insertion of the InSpace balloon (debridement with device group). Participants had an irreparable rotator cuff tear, which had not resolved with conservative treatment, and they had symptoms warranting surgery. Eligibility was confirmed intraoperatively before randomly assigning (1:1) participants to a treatment group using a remote computer system. Participants and assessors were masked to group assignment. Masking was achieved by using identical incisions for both procedures, blinding the operation note, and a consistent rehabilitation programme was offered regardless of group allocation. The primary outcome was the Oxford Shoulder Score at 12 months. Pre-trial simulations using data from early and late timepoints informed stopping boundaries for two interim analyses. The primary analysis was on a modified intention-to-treat basis, adjusted for the planned interim analysis. The trial was registered with ISRCTN, ISRCTN17825590. FINDINGS: Between June 1, 2018, and July 30, 2020, we assessed 385 people for eligibility, of which 317 were eligible. 249 (79%) people consented for inclusion in the study. 117 participants were randomly allocated to a treatment group, 61 participants to the debridement only group and 56 to the debridement with device group. A predefined stopping boundary was met at the first interim analysis and recruitment stopped with 117 participants randomised. 43% of participants were female, 57% were male. We obtained primary outcome data for 114 (97%) participants. The mean Oxford Shoulder Score at 12 months was 34·3 (SD 11·1) in the debridement only group and 30·3 (10·9) in the debridement with device group (mean difference adjusted for adaptive design -4·2 [95% CI -8·2 to -0·26];p=0·037) favouring control. There was no difference in adverse events between the two groups. INTERPRETATION: In an efficient, adaptive trial design, our results favoured the debridement only group. We do not recommend the InSpace balloon for the treatment of irreparable rotator cuff tears. FUNDING: Efficacy and Mechanism Evaluation Programme, a Medical Research Council and National Institute for Health and Care Research partnership.

Evolving Deep Architecture Generation with Residual Connections for Image Classification Using Particle Swarm Optimization.

Automated deep neural architecture generation has gained increasing attention. However, exiting studies either optimize important design choices, without taking advantage of modern strategies such as residual/dense connections, or they optimize residual/dense networks but reduce search space by eliminating fine-grained network setting choices. To address the aforementioned weaknesses, we propose a novel particle swarm optimization (PSO)-based deep architecture generation algorithm, to devise deep networks with residual connections, whilst performing a thorough search which optimizes important design choices. A PSO variant is proposed which incorporates a new encoding scheme and a new search mechanism guided by non-uniformly randomly selected neighboring and global promising solutions for the search of optimal architectures. Specifically, the proposed encoding scheme is able to describe convolutional neural network architecture configurations with residual connections. Evaluated using benchmark datasets, the proposed model outperforms existing state-of-the-art methods for architecture generation. Owing to the guidance of diverse non-uniformly selected neighboring promising solutions in combination with the swarm leader at fine-grained and global levels, the proposed model produces a rich assortment of residual architectures with great diversity. Our devised networks show better capabilities in tackling vanishing gradients with up to 4.34% improvement of mean accuracy in comparison with those of existing studies.

IoTNet: An Efficient and Accurate Convolutional Neural Network for IoT Devices.

Two main approaches exist when deploying a Convolutional Neural Network (CNN) on resource-constrained IoT devices: either scale a large model down or use a small model designed specifically for resource-constrained environments. Small architectures typically trade accuracy for computational cost by performing convolutions as depth-wise convolutions rather than standard convolutions like in large networks. Large models focus primarily on state-of-the-art performance and often struggle to scale down sufficiently. We propose a new model, namely IoTNet, designed for resource-constrained environments which achieves state-of-the-art performance within the domain of small efficient models. IoTNet trades accuracy with computational cost differently from existing methods by factorizing standard 3 × 3 convolutions into pairs of 1 × 3 and 3 × 1 standard convolutions, rather than performing depth-wise convolutions. We benchmark IoTNet against state-of-the-art efficiency-focused models and scaled-down large architectures on data sets which best match the complexity of problems faced in resource-constrained environments. We compare model accuracy and the number of floating-point operations (FLOPs) performed as a measure of efficiency. We report state-of-the-art accuracy improvement over MobileNetV2 on CIFAR-10 of 13.43% with 39% fewer FLOPs, over ShuffleNet on Street View House Numbers (SVHN) of 6.49% with 31.8% fewer FLOPs and over MobileNet on German Traffic Sign Recognition Benchmark (GTSRB) of 5% with 0.38% fewer FLOPs.

Wound complications after distal humerus fracture fixation: incidence, risk factors, and outcome.

BACKGROUND: This study set out to accurately determine the incidence of wound complications after distal humerus fracture fixation, to assess risk factors, and to determine their implications on outcome. METHODS: Eighty-nine distal humerus fractures (mean patient age, 58 years) were treated with internal fixation at an average of 4 days after injury. Mean follow-up time was 15 months (range, 6-72 months). Twenty-nine (33%) fractures were open. Medical records and radiographs were reviewed to determine wound complications. Logistic regression analysis was carried out to determine associated risk factors. RESULTS: Fourteen patients (15.7%) developed a major wound complication requiring on average 2.5 (range, 1-6) additional surgical procedures. Six patients required plastic surgical soft tissue coverage. All 14 fractures complicated by wound problems united. The final mean range of motion in the major wound complication group was 100° (range, 65°-130°), compared with 100° (range, 10°-140°) in those with no or minor wound problems. Grade III open fractures and the use of a plate to stabilize the olecranon osteotomy were identified as significant risk factors for development of major wound complications. CONCLUSIONS: The incidence of major wound complications after fixation of distal humerus fractures is substantial. The presence of a grade III open fracture and the use of an olecranon osteotomy stabilized with a plate are significant risk factors for major wound complications. Fracture healing rates and functional elbow range of motion do not appear to be affected by major wound complications when they are handled with proper soft tissue coverage techniques.

Cross-validation of two prognostic trauma scores in severely injured patients.

INTRODUCTION: Trauma scoring systems are important tools for outcome prediction and severity adjustment that informs trauma quality assessment and research. Discrimination and precision of such systems is tested in validation studies. The German TraumaRegister DGU® (TR-DGU) and the Trauma Audit and Research Network (TARN) from the UK agreed on a cross-validation study to validate their prediction scores (RISC II and PS14, respectively). METHODS: Severe trauma patients with an Injury Severity Score (ISS) ≥ 9 documented in 2015 and 2016 were selected in both registries (primary admissions only). The predictive scores from each registry were applied to the selected data sets. Observed and predicted mortality were compared to assess precision; area under the receiver operating characteristic curve was used for discrimination. Hosmer-Lemeshow statistic was calculated for calibration. A subgroup analysis including patients treated in intensive care unit (ICU) was also carried out. RESULTS: From TR-DGU, 40,638 patients were included (mortality 11.7%). The RISC II predicted mortality was 11.2%, while PS14 predicted 16.9% mortality. From TARN, 64,622 patients were included (mortality 9.7%). PS14 predicted 10.6% mortality, while RISC II predicted 17.7%. Despite the identical cutoff of ISS ≥ 9, patient groups from both registries showed considerable difference in need for intensive care (88% versus 18%). Subgroup analysis of patients treated on ICU showed nearly identical values for observed and predicted mortality using RISC II. DISCUSSION: Each score performed well within its respective registry, but when applied to the other registry a decrease in performance was observed. Part of this loss of performance could be explained by different development data sets: the RISC II is mainly based on patients treated in an ICU, while the PS14 includes cases mainly cared for outside ICU with more moderate injury severity. This is according to the respective inclusion criteria of the two registries. CONCLUSION: External validations of prediction models between registries are needed, but may show that prediction models are not fully transferable to other health-care settings.

Measuring the intensity of conflicts in conservation.

Conflicts between the interests of biodiversity conservation and other human activities pose a major threat to natural ecosystems and human well-being, yet few methods exist to quantify their intensity and model their dynamics. We develop a categorization of conflict intensity based on the curve of conflict, a model originally used to track the escalation and deescalation of armed conflicts. Our categorization assigns six intensity levels reflecting the discourse and actions of stakeholders involved in a given conflict, from coexistence or collaboration to physical violence. Using a range of case studies, we demonstrate the value of our approach in quantifying conflict trends, estimating transition probabilities between conflict stages, and modeling conflict intensity as a function of relevant covariates. By taking an evidence-based approach to quantifying stakeholder behavior, the proposed framework allows for a better understanding of the drivers of conservation conflict development across a diverse range of socioecological scenarios.

Epidemiology of adult rib fracture and factors associated with surgical fixation: Analysis of a chest wall injury dataset from England and Wales.

INTRODUCTION: Chest wall trauma is commonly seen in patients admitted with both high and low-energy transfer injury. Whilst often associated with other injuries, it is also seen in isolation following simple falls in the older patient. Fixation of the chest wall grows in popularity as part of optimising patient care, particularly in terms of critical care stay. There is currently no description of the epidemiology of these injuries at a national level; nor has there been identification of factors that predict which of these patients undergoes surgery. METHODS: The United Kingdom Trauma Audit & Research Network (TARN) database was analysed for the period April 2016 to 30th May 2017 for all adult patients presenting with a rib or sternal fracture. Characteristics of the population were described and a binary logistic regression model constructed to explore the influences of several explanatory variables on whether fixation was performed. RESULTS: Of 16,638 patients with chest wall trauma, 402 underwent fixation. Most chest wall injury patients were admitted under three specialties (orthopaedics (19.1%), emergency medicine (16.6%) and general surgery (17.7%)). The odds of fixation in unilateral flail chest was 107.51 (p <0.0001), in bilateral flail or combined complexsternal fracture 47.63 (p = 0.007) and in 3 or more non-flail ribs 15.62 (p<0.0001) when compared to less than three non-flail rib fractures. The odds of fixation was higher in an MTC (p<0.0001) compared to a non-specialist hospital. The odds of fixation was higher in older patients (1.02, p<0.0001) and the more severely injured (1.02, p<0.0001). CONCLUSION: There is considerable variation nationally in the management of chest wall trauma. Injury type, patient age and care setting contribute to decision making in fracture fixation. This unique national dataset characterises for the first time the nature of contemporary chest wall trauma management and should help inform the design of future research on this topic.

Serious sports-related injury in England and Wales from 2012-2017: a study protocol.

BACKGROUND: Physical activity is an important component of healthy lifestyles, with a central role in morbidity prevention. However, sporting and physical activity also involve an inherent injury risk. Some sports and activities have a higher injury risk, and may involve more severe injuries. Furthermore, injuries of a severe nature have substantial individual and societal consequences, including the burden of assessment, treatment, and potential on-going care costs. There are limited data on severe sports injury risk in England and Wales, and no national data describing risk across sports. The aims of this study are to identify the cases and incidence of: i) paediatric and ii) adult severe sports injury from 2012 to 2017; and to describe injury incidence in individual sports. METHODS: This study is an analysis of prospectively collected sport-related injuries, treated from January 2012 to December 2017. Incidents involving a severe injury (in-patient trauma care) in England and Wales, will be identified from the Trauma Audit Research Network registry. Data for patients who were: transfers or direct hospital admissions, with inpatient stays of ≥3 days, admissions to High Dependency areas, or in-hospital mortality after admission; and whose injury mechanism was sport, or incident description included one of 62 sporting activities, will be extracted. Data will be categorised by sport, and sports participation data will be derived from Sport England participation surveys. Descriptive statistics will be estimated for all demographic, incident, treatment and sport fields, and crude serious annual injury incidence proportions estimated. Poisson confidence intervals will be estimated for each sport and used to describe injury risk (incidence) across sporting activities. DISCUSSION: This study will be the first to describe the number of, and trends in severe sport-related injuries in England and Wales. These data are useful to monitor the number and burden of severe sports injury, and inform injury prevention efforts. The monitoring and mitigation of sports injury risk is essential for individuals, health services and policy, and to encourage physically active lifestyles and safer participation for adults and children.

Cycling related major trauma in Ireland.

INTRODUCTION: Cycling as a means of transport or recreational activity is increasing in popularity in Ireland. However, increasing numbers of cyclists may lead to an increased number of bicycle collisions and fatalities. The Road Safety Authority is the statutory body for road safety in Ireland but uses police data alone to collate cycling collision statistics. This may lead to an underestimation of cycling injuries in Ireland. Using hospital statistics may provide a greater understanding of cycling trauma in Ireland. OBJECTIVE: The present study examines cycling related trauma in Ireland using the Major Trauma Audit (MTA) data collected via the Trauma and Research Network (TARN) from hospitals in Ireland for the period 2014 to 2016. The database was interrogated for demographics, mechanism of injury, injury characteristics and patient outcomes. RESULTS: There were 410 cycling collisions recorded in the TARN database which represented 4.4% of trauma captured by TARN for the study period. Of this cohort 79% were male compared with 58% in the overall (TARN) trauma cohort (p < 0.001) and the median (IQR) age was 43.8 years (31.0, 55.7) which is younger than the median (IQR) of 58.9 (36.2, 76.0) years for the overall trauma cohort (p < 0.001). Cycling collisions had a median (IQR) injury severity score (ISS) of 10 (9, 20) which was higher than the overall trauma cohort ISS of 9 (9, 17). Of the mechanisms observed for cycling trauma, 31.7% (n = 130) had a collision with a motor vehicle. Of those who did not wear a helmet, 52.2% (n = 47) sustained a head injury compared with 27.5% (n = 44) in the group who were wearing a helmet (p < 0.001). CONCLUSION: The TARN data presented in this paper builds a more complete overview of the burden of cycling collisions in Ireland. Particular points of focus are that serious cycling injuries occur in a predominantly male population, and that only around 30% of cases are recorded as involving a motor vehicle, with the majority having an unknown mechanism of injury. There was an association between helmets and head injuries in this study, but there are likely other contributing factors such as mechanism of injury, velocity or cycling infrastructure. Using hospital data such as the MTA provides valuable information on the injuries sustained by cyclists, but more prospective studies to capture injury mechanism and contributing factors are needed.

Protocol for a randomised controlled trial of Subacromial spacer for Tears Affecting Rotator cuff Tendons: a Randomised, Efficient, Adaptive Clinical Trial in Surgery (START:REACTS).

INTRODUCTION: Shoulder pain due to irreparable rotator cuff tears can cause substantial disability, but treatment options are limited. A balloon spacer is a relatively simple addition to a standard arthroscopic debridement procedure, but it is costly and there is no current randomised trial evidence to support its use. This trial will evaluate the clinical and cost-effectiveness of a subacromial balloon spacer for individuals undergoing arthroscopic debridement for irreparable rotator cuff tears.New surgical procedures can provide substantial benefit to patients. Good quality randomised controlled trials (RCTs) are needed, but trials in surgery are typically long and expensive, exposing patients to risk and the healthcare system to substantial costs. One way to improve the efficiency of trials is with an adaptive sample size. Such methods are well established in drug trials but have rarely, if ever, been used in surgical trials. METHODS AND ANALYSIS: Subacromial spacer for Tears Affecting Rotator cuff Tendons: a Randomised, Efficient, Adaptive Clinical Trial in Surgery (START:REACTS) is a participant and assessor blinded, adaptive, multicentre RCT comparing arthroscopic debridement with the InSpace balloon (Stryker, USA) to arthroscopic debridement alone for people with a symptomatic irreparable rotator cuff tear. It uses a group sequential adaptive design where interim analyses are performed using all of the 3, 6 and 12-month data that are available at each time point. A maximum of 221 participants will be randomised (1:1 ratio), this will provide 90% power (at the 5% level) for a 6 point difference in the primary outcome; the Oxford Shoulder Score at 12 months. A substudy will use deltoid-active MRI scans in 56 participants to assess the function of the balloon. Analysis will be on an intention-to-treat basis and reported according to principles established in the Consolidated Standards of Reporting Trials statement. ETHICS AND DISSEMINATION: NRES number 18/WM/0025. The results will be disseminated via peer-reviewed publications, presentations at conferences, lay summaries and social media. TRIAL REGISTRATION NUMBER: ISRCTN17825590.

An assessment of porcine dermal xenograft as an augmentation graft in the treatment of extensive rotator cuff tears.

Porcine dermal collagen (Zimmer Patch, formerly known as Permacol; Tissue Science Laboratories plc, Aldershot, Hampshire, UK) has been used for reinforcement of several human body tissues with success and has been shown to act as a durable, permanent tissue scaffold that assists healing. The purpose of this study was to determine the effectiveness of porcine dermal collagen as a tendon augmentation graft in the repair of extensive rotator cuff tears. This prospective study evaluated the clinical, ultrasound, and magnetic resonance imaging outcome 4.5 years (range, 3-5 years) after the treatment of extensive rotator cuff tears with porcine dermal collagen tendon augmentation grafting. The study group consisted of 10 patients (5 men, 5 women) with a mean age of 66 years (range, 46-80 years). Patients were evaluated clinically using the Constant score preoperatively, at 1 year, and at final follow-up when ultrasound and magnetic resonance imaging scans were performed to assess for graft and rotator cuff integrity. Average Constant scores improved from 41 preoperatively to 62 at final follow-up (P = .0003). Pain, abduction power, and range of motion significantly improved after surgery (P < .05), and patient satisfaction levels were high. Imaging studies identified intact grafts in 8 patients and graft detachment in 2. No adverse side effects were reported during the study period. The use of porcine dermal collagen as an augmentation graft in the treatment of massive rotator cuff tears is safe and, in most patients, is associated with improved clinical outcome. Randomized trials are required to assess any benefit over standard current surgical treatment regimens.

Changing the System - Major Trauma Patients and Their Outcomes in the NHS (England) 2008-17.

BACKGROUND: Trauma care in England was re-organised in 2012 with ambulance bypass of local hospitals to newly designated Major Trauma Centres (MTCs). There is still controversy about the optimal way to organise health series for patients suffering severe injury. METHODS: A longitudinal series of annual cross-sectional studies of care process and outcomes from April 2008 to March 2017. Data was collected through the national clinical audit of major trauma care. The primary analysis was carried out on the 110,863 patients admitted to 35 hospitals that were 'consistent submitters' throughout the study period. The main outcome was longitudinal analysis of risk adjusted survival. FINDINGS: Major Trauma networks were associated with significant changes in (1) patient flow (with increased numbers treated in Major Trauma Centres), (2) treatment systems (more consultant led care and more rapid imaging), (3) patient factors (an increase in older trauma), and (4) clinical care (new massive transfusion policies and use of tranexamic acid). There were 10,247 (9.2%) deaths in the 110,863 patients with an ISS of 9 or more. There were no changes in unadjusted mortality. The analysis of trends in risk adjusted survival for study hospitals shows a 19% (95% CI 3%-36%) increase in the case mix adjusted odds of survival from severe injury over the 9-year study period. Interrupted time series analysis showed a significant positive change in the slope after the intervention time point of April 2012 (+ 0.08% excess survivors per quarter, p = 0.023), in other words an increase of 0.08 more survivors per 100 patients every quarter. INTERPRETATION: A whole system national change was associated with significant improvements in both the care process and outcomes of patients after severe injury. FUNDING: This analysis was carried out independently and did not receive funding. The data collection for the national clinical audit was funded by subscriptions from participating hospitals.

Canopy bird assemblages are less influenced by habitat age and isolation than understory bird assemblages in Neotropical secondary forest.

Secondary forest habitats are increasingly recognized for their potential to conserve biodiversity in the tropics. However, the development of faunal assemblages in secondary forest systems varies according to habitat quality and species-specific traits. In this study, we predicted that the recovery of bird assemblages is dependent on secondary forest age and level of isolation, the forest stratum examined, and the species' traits of feeding guild and body mass. This study was undertaken in secondary forests in central Panama; spanning a chronosequence of 60-, 90-, and 120-year-old forests, and in neighboring old-growth forest. To give equal attention to all forest strata, we employed a novel method that paired simultaneous surveys in canopy and understory. This survey method provides a more nuanced picture than ground-based studies, which are biased toward understory assemblages. Bird reassembly varied according to both habitat age and isolation, although it was challenging to separate these effects, as the older sites were also more isolated than the younger sites. In combination, habitat age and isolation impacted understory birds more than canopy-dwelling birds. Proportions of dietary guilds did not vary with habitat age, but were significantly different between strata. Body mass distributions were similar across forest ages for small-bodied birds, but older forest supported more large-bodied birds, probably due to control of poaching at these sites. Canopy assemblages were characterized by higher species richness, and greater variation in both dietary breadth and body mass, relative to understory assemblages. The results highlight that secondary forests may offer critical refugia for many bird species, particularly specialist canopy-dwellers. However, understory bird species may be less able to adapt to novel and isolated habitats and should be the focus of conservation efforts encouraging bird colonization of secondary forests.

Modified Weaver-Dunn procedure versus the use of a synthetic ligament for acromioclavicular joint reconstruction.

PURPOSE. To compare the subjective outcome of acromioclavicular joint (ACJ) reconstruction using the modified Weaver-Dunn procedure versus the Surgilig synthetic ligament. METHODS. 55 patients aged 19 to 72 (mean, 42) years underwent ACJ reconstruction of Rockwood grade 3 (n=38), grade 4 (n=8), and grade 5 (n=9) using the modified Weaver-Dunn procedure (n=31) or the Surgilig synthetic ligament (n=24), based on the surgeon's preference. The mean period from injury to surgical treatment was 39 months. Subjective outcomes were assessed before and after surgery using the Oxford Shoulder score and Nottingham Clavicle score. The time required to return to work and sports was also recorded. RESULTS. After a mean follow-up period of 40 months, the mean Oxford Shoulder scores improved from 28 to 42 in the Weaver-Dunn group (p=0.009), and from 26 to 45 in the Surgilig group (p=0.007), whereas the respective mean Nottingham Clavicle scores improved from 53 to 81 (p=0.047) and from 51 to 93 (p=0.023). The Surgilig group achieved significantly better postoperative Oxford Shoulder score (p=0.008) and Nottingham Clavicle score (p=0.007), and could also return to work (14 vs. 6 weeks, p<0.001) and sports (25 vs. 12 weeks, p<0.001) sooner than the Weaver-Dunn group. Three patients in the Weaver- Dunn group and one patient in the Surgilig group had persistent pain and/or functional deficit with evidence of ACJ dislocation. CONCLUSION. Chronic ACJ reconstruction using the Surgilig synthetic ligament achieved better Oxford Shoulder score and Nottingham Clavicle score and earlier return to work and sports, compared with the modified Weaver-Dunn procedure.

A biomechanical analysis of suture materials and their influence on a four-strand flexor tendon repair.

PURPOSE: Flexor tendon repair strength depends on the suture technique and the suture material used. Configurations that incorporate locking loops prevent sutures from pulling through the tendon but typically fail because of suture breakage. The choice of suture material therefore influences repair strength. This study investigated the mechanical properties of 5 nonabsorbable 4-0 suture materials (monofilament nylon, monofilament polypropylene, braided polyester, braided stainless steel wire, and braided polyethylene) and evaluated their performance when used in a locking 4-strand flexor tendon repair configuration. METHODS: Five samples of 2 strands of each suture type were tested mechanically to determine the material stiffness and ultimate load. In addition, 50 fresh porcine flexor tendons were divided and repaired with each of the 5 suture materials using a 4-strand single-cross technique. Gap force, ultimate strength, and stiffness were measured to compare biomechanical performance. RESULTS: All repairs failed by suture rupture at the locking loop. Fibrewire and stainless-steel sutures and repairs were significantly stronger and stiffer than the other suture types. The results for Prolene and Ethibond were similar in the tendon repair groups with respect to gap and ultimate forces although Ethibond provided significantly increased repair stiffness. Nylon sutures and repairs consistently produced the poorest mechanical performance in all outcome measures. CONCLUSIONS: Suture material strongly influences the biomechanical performance of multistrand tendon repairs and is an important consideration for the surgeon. Fibrewire and stainless steel are the most biomechanically suitable suture materials for flexor tendon repair whereas nylon is the least suitable. Further developments in suture materials are important for advancements in flexor tendon repair strength.

Medical counterbioterrorism: the response to provide anthrax prophylaxis to New York City US Postal Service employees.

STUDY OBJECTIVE: We describe and analyze a recent rapid deployment of disaster medical assistance teams and other government agencies to provide medical screening and anthrax prophylaxis to New York City US Postal Service employees potentially exposed to letters contaminated with anthrax spores. METHODS: A description of the response effort is presented. Data were collected on standardized forms and included the numbers of postal employees screened and offered antibiotic prophylaxis, as well as the numbers of patients seen per worker hour by various medical professionals. RESULTS: One hundred members of 5 disaster medical assistance teams and other health professionals were deployed to New York City within 18 hours of activation. Over a 68-hour period, 7,076 patients were evaluated, representing all postal employees in the 6 major postal facilities in New York believed to be at risk for anthrax exposure. Of the total, 2,452 patients were seen during the first 24 hours, 3,875 during the second 24 hours, and the remaining 749 during the last 20 hours of operations. An average of 161 employees were screened per hour. The antibiotic most commonly dispensed was ciprofloxacin, followed by doxycycline and amoxicillin. CONCLUSION: The deployment of disaster medical assistance teams and other agencies to New York City to provide prophylaxis against inhalation anthrax to US Postal Service employees provides lessons for a rapid, efficient, and effective response to acts of bioterrorism. This deployment might also serve as a scaleable model for future events requiring medical prophylaxis.