Linking pesticide exposure to neurodegenerative diseases: An in vitro investigation with human neuroblastoma cells

Although many organochlorine pesticides (OCPs) have been banned or restricted because of their persistence and linkage to neurodegenerative diseases, there is evidence of continued human exposure. In contrast, registered herbicides are reported to have a moderate to low level of toxicity; however, there is little information regarding their toxicity to humans or their combined effects with OCPs. This study aimed to characterize the mechanism of toxicity of banned OCP insecticides (aldrin, dieldrin, heptachlor, and lindane) and registered herbicides (trifluralin, triallate, and clopyralid) detected at a legacy contaminated pesticide manufacturing and packing site using SH-SY5Y cells. Cell viability, LDH release, production of reactive oxygen species (ROS), and caspase 3/7 activity were evaluated following 24 h of exposure to the biocides. In addition, RNASeq was conducted at sublethal concentrations to investigate potential mechanisms involved in cellular toxicity. Our findings suggested that aldrin and heptachlor were the most toxic, while dieldrin, lindane, trifluralin, and triallate exhibited moderate toxicity, and clopyralid was not toxic to SH-SY5Y cells. While aldrin and heptachlor induced their toxicity through damage to the cell membrane, the toxicity of dieldrin was partially attributed to necrosis and apoptosis. Moreover, toxic effects of lindane, trifluralin, and triallate, at least partially, were associated with ROS generation. Gene expression profiles suggested that decreased cell viability induced by most of the tested biocides was related to inhibited cell proliferation. The dysregulation of genes encoding for proteins with anti-apoptotic properties also supported the absence of caspase activation. Identified enriched terms showed that OCP toxicity in SH-SY5Y cells was mediated through pathways associated with the pathogenesis of neurodegenerative diseases. In conclusion, this study provides a basis for elucidating the molecular mechanisms of pesticide-induced neurotoxicity. Moreover, it introduced SH-SY5Y cells as a relevant in vitro model for investigating the neurotoxicity of pesticides in humans.

Herbicides and pesticides synergistically interact at low concentrations in complex mixtures

Assessing a complex mixture of pesticides at the impacted sites has been challenging for risk assessors for 50 years. The default assumption is that at low concentrations, pesticides interact additively with one another; thus, the risk posed by each component of a complex mixture could be simply added up. The EPA interaction-based hazard index (HIInteraction) modifies this assumption using a binary weight-of-evidence (BINWOE). However, data gaps often preclude HIInteraction use at most sites. This study evaluated these assumptions using the BINWOE to estimate the hazard index (HI) of select pesticide mixtures. The lack of in vivo binary interaction data led us to use a cell line, SH-SY5Y, to obtain the data necessary for the BINWOE approach. In the risk assessment, we considered the most active exposure scenario inhaling a mixture of volatile pesticides from contaminated soil and groundwater. The potential interactions between pesticides in 15 binary mixtures were investigated using the MTT assay in SH-SY5Y cells. Our findings showed that 60% of the binary mixtures elicited synergism (in at least one concentration), 27% displayed antagonism, and 13% showed additive effects in SH-SY5Y cells. Combining human safety data with in vitro interaction data indicated that adults and toddlers were at the highest risk when considering industrial and commercial land use, respectively, compared to other subpopulations. Incorporating interaction data into the risk assessment either increased the risk by up to 20% or decreased the risk by 2%, depending on the mixture. Our results demonstrate the predominant synergistic interactions, even at low concentrations, altered risk characterization at the complex operating site. Most concerning, organochlorine pesticides with the same mechanism of action did not follow dose additivity when evaluated by SH-SY5Y cell lines. Based on our observations, we caution that current HI methods based on additivity assumptions may underestimate the risk of organochlorine mixtures.

In-Hospital Hip Fractures in a Large Irish Teaching Hospital: Patient Risk Factors and Outcomes

INTRODUCTION

In-hospital hip fractures follow falls during unrelated admissions. Little data in the Irish setting is available on this vulnerable subset of hip fracture patients. Our objective is to review the incidence of in-hospital hip fractures, identify risk factors, and evaluate outcomes.

METHODS

This is a retrospective observational review. We collected patient data in St. James' Hospital using the Hospital In-Patient Enquiry database and Electronic Patient Records for in-hospital hip fractures between 10/02/2017 and 22/04/2020. Comorbidity, survival, and discharge destination data were gathered.

RESULTS

We identified 40 fractures, representing 11.5% of all hip fractures treated at our center during the study period. The patients were 60-95 years old. Median age was 77 years for males and 86 years for females. Most (72.5%) were identified as fall risks, and 52% were unwitnessed falls. Many had a history of falls (67.5%), dementia (52.5%), or both (42.5%). Delirium was common (42.5%), and 75% had at least one vascular/coagulation disorder. Mortality was 10.25% at 30 days, 23.1% at 90 days, and 51.4% at 12 months. Although 70% were admitted from home, only 10% were discharged back home. 30% were admitted to a nursing home, and 55% were discharged from a nursing home.

CONCLUSION

In-hospital hip fractures accounted for 11.5% of all hip fractures treated at our center, confirming the need for a well-defined hospital protocol. Patients often present with previous falls, dementia, and cardiovascular disease. Outcomes are poor, with 51.4% mortality at 12 months and significant morbidity reflected by a loss of independent living.

Target Organ Toxicity in Rats After Subchronic Oral Exposure to Soil Extracts Containing a Complex Mixture of Contaminants

Complex mixtures of unknown contaminants present a challenge to identify toxicological risks without using large numbers of animals and labor-intensive screens of all organs. This study examined soil extracts from a legacy-contaminated pesticide packaging and blending site. HepG2 cytotoxicity was used as an initial screen of 18 soil samples; then, three extracts (A, B and C) from different locations at the study site were used for testing in animals. The first two extracts were identified as the most toxic in vitro, and the latter extract obtained from a location further from these two toxic sampling sites. Then, target organ toxicities were identified following biweekly oral gavage for one month of three soil extracts (0.1% in polyethylene glycol or PEG) compared to vehicle control in male Sprague-Dawley rats (n = 9-10/group). Exposure to extract A significantly increased neutrophils and lymphocytes compared to control. In contrast, all extracts increased plasma α-2 macroglobulin and caused mild-to-moderate lymphocytic proliferation within the spleen white pulp, all indicative of inflammation. Rats exposed to all soil extracts exhibited acute tubular necrosis. Cholinesterase activity was significantly reduced in plasma, but not brain, after exposure to extract A compared to control. Increased hepatic ethoxyresorufin-o-deethylase activity compared to control was observed following exposure to extracts A and B. Exposure to soil extract C in rats showed a prolonged QTc interval in electrocardiography as well as increased brain lipid peroxidation. Candidate contaminants are organochlorine, organophosphate/carbamate pesticides or metabolites. Overall, HepG2 cytotoxicity did not successfully predict the neurotoxicity and cardiotoxicity observed with extract C but was more successful with suspected hydrocarbon toxicities in extracts A and B. Caution should be taken when extrapolating the observation of no effects from in vitro cell culture to in vivo toxicity, and better cell culture lines or assays should be explored.

Readability of Patient Educational Materials in Sports Medicine

Background:

The internet has become an increasingly popular resource among sports medicine patients seeking injury-related information. Numerous organizations recommend that patient educational materials (PEMs) should not exceed sixth-grade reading level. Despite this, studies have consistently shown the reading grade level (RGL) of PEMs to be too demanding across a range of surgical specialties.

Purpose:

To determine the readability of online sports medicine PEMs.

Study Design:

Cross-sectional study.

Methods:

The readability of 363 articles pertaining to sports medicine from 5 leading North American websites was assessed using 8 readability formulas: Flesch-Kincaid Reading Grade Level, Flesch Reading Ease Score, Raygor Estimate, Fry Readability Formula, Simple Measure of Gobbledygook, Coleman-Liau Index, FORCAST Readability Formula, and Gunning Fog Index. The mean RGL of each article was compared with the sixth- and eighth-grade reading level in the United States. The cumulative mean website RGL was also compared among individual websites.

Results:

The overall cumulative mean RGL was 12.2 (range, 7.0-17.7). No article (0%) was written at a sixth-grade reading level, and only 3 articles (0.8%) were written at or below the eighth-grade reading level. The overall cumulative mean RGL was significantly higher than the sixth-grade [95% CI for the difference, 6.0-6.5; P < .001] and eighth-grade (95% CI, 4.0-4.5; P < .001) reading levels. There was a significant difference among the cumulative mean RGLs of the 5 websites assessed.

Conclusion:

Sports medicine PEMs produced by leading North American specialty websites have readability scores that are above the recommended levels. Given the increasing preference of patients for online health care materials, the imperative role of health literacy in patient outcomes, and the growing body of online resources, significant work needs to be undertaken to improve the readability of these materials.

Perioperative haematological outcomes following total knee arthroplasty in haemophiliacs

PURPOSE

Patients with haemophilia suffer from recurrent joint haemarthrosis. This can progress to symptomatic arthropathy commonly affecting the knee. While modern coagulation strategies have reduced those proceeding to end-stage arthropathy, total knee arthroplasty (TKA) remains the optimal treatment for some patients. Despite innovation in perioperative haematological management, concerns about the potential for excessive haemorrhage still exist. The aim of this study is to quantify immediate postoperative blood loss and haematological complications in haemophiliacs following TKA.

METHODS

A retrospective study of patients with haemophilia types A or B who underwent a TKA over a 12-year period at a single institution was conducted. These patients were compared to both a non-haemophiliac control group and to published standards in non-haemophiliacs undergoing TKA.

RESULTS

Twenty-one TKA procedures in 18 patients (72% haemophilia A, 28% haemophilia B) were suitable for inclusion with a mean age of 44 years. The mean haemoglobin drops at 24 and 48 h postoperatively were 2.7 g/dl and 3.8 g/dl respectively. There was no significant difference in haemoglobin drop at 48 h postoperatively when compared to the non-haemophiliac control group (P = 0.2644). There were no immediate perioperative complications and two patients (9.6%) required postoperative transfusion.

CONCLUSION

Haemophiliacs undergoing a unilateral primary TKA in a specialised tertiary referral centre appear to have comparable rates of perioperative blood loss when compared to both a non-haemophiliac control group as and published haemostatic standards in non-haemophiliac patients following TKA. Perioperative management with expert orthopaedic and haematological input is recommended to optimise outcomes in this complex patient group.

Health status of fathead minnow (Pimephales promelas) populations in a municipal wastewater effluent-dominated stream in the Canadian prairies, Wascana Creek, Saskatchewan

Their unique hydrological and climatic conditions render surface water systems in the southern Canadian Prairies at an elevated risk from exposure to contaminants released from municipal wastewater effluents (MWWEs). The aim of this study was to characterize the potential health effects and their underlying molecular mechanisms in populations of fathead minnow (Pimephales promelas; FHM) in Wascana Creek, an effluent dominated stream in Southern Saskatchewan, Canada. Studies were conducted during the spawning season in 2014 and 2015 to assess responses in terms of overall health, reproductive functions, plasma sex steroid hormone levels, and expression of selected genes along the hypothalamus-pituitary-gonadal axis. FHM downstream of the effluent fallout had lower gonadosomatic indices and significantly greater hepatosomatic indices compared to upstream populations. In both male and female FHMs, significantly greater occurrence and severity of gonadal degradation and delayed maturation were observed in downstream fish compared to upstream fish. Downstream males also displayed lower scores of secondary sexual characteristics and a decreasing trend in plasma 11-ketotestosterone levels. Interestingly, no indications of exposure to estrogenic compounds, such as occurrence of testicular oocytes were observed, which was in accordance with the lack of presence of key biomarkers of estrogenic exposure, such as induction of vitellogenin. In general, expression of the majority of transcripts measured in FHMs downstream of the effluent fallout was significantly downregulated, which supports observations of the general deterioration of the health and reproductive status of these fish. Chemical analysis indicated that 10 pharmaceuticals and personal care products (PPCPs) were present at the downstream site, some at sufficiently great concentrations that may present a risk to aquatic organisms. With continuous exposure to a diverse number of stressors including high nutrient and ammonia levels, the presence of a variety of PPCPs and other contaminants, Wascana Creek should be considered as an ecosystem at risk.

Osteotomy around the knee: Assessment of quality, content and readability of online information

BACKGROUND

As knee osteotomy surgery becomes increasingly accessible, more patients may turn to the Internet for information. This study examined the source, quality, content and readability of online information regarding osteotomy around the knee.

METHODS

The first 70 websites returned by the top four search engines were identified using the key words: "knee osteotomy" and "high tibial osteotomy." The websites were categorised by type and assessed using the DISCERN score, Journal of the American Medical Association (JAMA) benchmark criteria and a novel Knee Osteotomy-Specific Score (KOSS). The presence of the Health On the Net (HON) code accreditation seal was noted. Readability of each website was assessed using eight readability formulae. The mean reading grade level (RGL) was compared to the 6th and 8th grade reading levels. The mean RGL of each category was also compared.

RESULTS

Of the 45 unique websites analysed, the majority were Physician (33%) and Journal websites (31%). The mean DISCERN score was 36.7 (±8.9) which is classified as 'poor.' The mean JAMA benchmark criteria score was 2.04 (±1.5) and Physician websites were most likely to be scored zero. The mean KOSS was 15.4 (±5.7). The highest scoring website was a Commercial site but, overall, Journal category sites provided the best quality information. Websites that bore the HONcode seal obtained higher DISCERN, JAMA benchmark criteria and Knee Osteotomy - Specific Scores. The cumulative mean RGL was 13.2 (±2.2) which exceeded the 6th grade level by an average of 7.2 grade levels and the 8th grade level by an average of 5.2 grade levels. No website (0%) was written at or below either the 6th or the 8th grade reading levels. The mean Flesch Reading Ease Score of all websites was 41.13 (±14.7) which is classified as 'difficult.' Journal websites had the highest RGL.

CONCLUSION

The information available online regarding osteotomy around the knee varies tremendously in quality and completeness. Physician sites predominate, but these were among the lowest scoring of all websites. Even where high quality information is available, it is set at too high a level to be easily understood.

LEVEL OF EVIDENCE

Survey of materials - Internet.

Knee osteotomy: Quality tools and readability data of information on the internet

Supplementary data for the article Osteotomy around the Knee: Assessment of Quality, Content and Readability of Online Information is provided. 45 unique websites were evaluated. The DISCERN score, JAMA (Journal of the American Medical Association) benchmark criteria and HONcode (Health On the Net) criteria are provided for reference. Readability of online information was analysed with Readability Studio Professional Edition, Version 2019 (Oleander Software Ltd.). The software assessed readability using eight different instruments: Flesch-Kincaid Reading Grade Level (FKGL), Flesch Reading Ease Score (FRES), Raygor Estimate, SMOG, Coleman- Liau, Fry, FORCAST and Gunning Fog. Data is also provided on the percentage of complex words, long words, Dale-Chall unfamiliar words, Fog words, as well as the number of ‘wordy’ items, overly long sentences and longest sentence length.

Incidence of Non-Simultaneous Contralateral Second Hip Fractures: A Single-Center Irish Study

Introduction

Hip fractures are a significant cause of morbidity and mortality in the elderly and are also associated with increased healthcare costs. A second contralateral hip fracture can lead to even more complications and healthcare costs. A significant proportion of the Irish hip fracture population does not receive a bone health assessment or falls specialist assessment to reduce the risk of future falls and fractures. This study aimed to analyze the incidence of a non-simultaneous contralateral hip fracture in an Irish population.

Methods

We retrospectively analyzed 1,344 patients presenting to our institution with a hip fracture from January 2007 to June 2019. Patients aged ≥ 60 years old presenting with a neck of femur or pertrochanteric fracture were included in our study. We excluded patients who had sub-trochanteric and femoral shaft fractures, high energy fractures, and pathological fractures. We also excluded patients less than 60 years old, as fractures in these younger patients may not be purely related to osteoporosis.

Results

A total of 1,099 hip fractures meeting the inclusion criteria were treated at our unit during the designated time period. A total of 102 (9.3%) patients experienced a second hip fracture. The mean age at first presentation in our institution was 78.5 years old, with a mean time between first and second hip fractures of 37.2 months.

Conclusions

Patients presenting with a second hip fracture may represent 9.3% of the Irish hip fracture population. We hope that this study will help inform on the rate of second hip fractures in an Irish population and help advocate for improved resources and implementation of secondary prevention strategies.

Skin Puckering in a Tibial Fracture

Skin puckering is a feature observed in fractures that undergo large displacements at the time of initial injury and occur as a result of adherence of the dermal tissues to the underlying fracture fragment. Herein, we discuss the interesting case of a 47-year-old male who suffered a comminuted tibial shaft fracture which resulted in marked pretibial skin puckering prior to fracture reduction with striking corresponding images noted on computerised tomography (CT) scanning. 

Predisposing Factors and Outcomes After Prolonged Admission Following Hip Fracture

Introduction Hip fractures are increasingly prevalent and can result in substantial morbidity, mortality, and cost. Despite the existence of enhanced management strategies, prolonged hip fracture admissions persist. This study's objective was to ascertain characteristics associated with a prolonged length of stay (LOS) and quantify return to baseline once discharged. Methods A retrospective audit of hip fractures over a four-year period was conducted, identifying patients with a LOS over 100 days. Demographics, comorbidities, pre- and post-admission function, and status were assessed. Patients sustaining inpatient hip fractures were excluded to negate the effect of initial admission on LOS. Results Seven hundred and eleven hip fractures were treated, of which 48 (6.8%) were suitable for inclusion. The patients' median age and LOS was 83.5 years and 153 days, respectively. Preoperative American Society of Anesthesiologists - Physical Status (ASA-PS) Grades II and III predominated at 41.7% and 39.6%, respectively. Eighteen of patients had a diagnosis of dementia before admission, increasing to 29 on discharge (P = 0.0026). One patient was in long-term care prior to admission, rising to 30 on discharge (P < 0.0001), with only 25.6% returning to pre-admission residential status (P < 0.0001). Nineteen patients were mobilising unaided prior to admission, decreasing to only two following discharge, with a mere 37.1% returning to their pre-admission mobility baseline (P < 0.0001). Discussion Hip fracture patients with multiple comorbidities or a diagnosis of dementia were most likely to have a prolonged LOS which, in turn, impacted upon return to baseline mobility, cognitive status, and independence. Early identification and management of this cohort may help reduce the potential disease burden and economic effects that a prolonged LOS creates.

Single versus separate implant fixation for concomitant ipsilateral femoral neck and shaft fractures: A systematic review

Concomitant ipsilateral femoral neck and shaft fractures are uncommon, occurring in 1-9% of femoral shaft fractures. While this injury typically occurs in young patients following high-energy trauma, little consensus has been established regarding the optimal fixation approach. A multitude of treatment strategies exist, with limited evidence as to which is more favorable. The aim of this study was to appraise current evidence, comparing management with either one single or separate devices for both fractures. A systematic review was undertaken in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies published between 1992 and 2018 comparing the rate of postoperative nonunion, malunion, delayed union, avascular necrosis, infection or reoperation between at least one method of single device fixation and one method of separate device fixation were included. Six non-randomized cohort studies assessing 173 patients were suitable for inclusion, each comparing single device cephalomedullary nail fixation of both fractures with a combination of devices. All patients presented following high-energy trauma, at a median age of 32 years. While low complication rate and favorable outcomes were found across both groups, no significant difference could be inferred between either treatment strategy. This injury continues to occur in the traditionally described patient group, and results in acceptable postoperative outcomes. A paucity of randomized studies limits the ability to recommend a single or separate device treatment approach, and as such prospective, randomized trials with adequately powered sample sizes are required to definitively compare surgical management strategies in this rare but complex injury.

Diagnosis of human immunodeficiency virus following femoral head harvest post-total hip arthroplasty

Elective total hip arthroplasty (THA) is a routine procedure. Intraoperative harvesting of excised femoral heads for the purpose of donation during this procedure has become standard practice, in response to increasing bone allograft demand. Robust patient screening and femoral head analysis typically occurs, to minimize the risk of disease transmission to any potential recipient. Screening for human immunodeficiency virus (HIV), a virus normally first diagnosed through serological testing, makes up part of this process. This case describes a 43-year-old male who underwent elective THA, with subsequent analysis of the excised femoral head at time of screening revealing a diagnosis of HIV, a condition previously never detected in the donor. First diagnosis of HIV from bone is exceedingly rare, with this case illustrating an unusual diagnostic pathway of a well-understood condition, as well as representing an unfamiliar outcome following a common surgical intervention.

Canal to diaphysis ratio as a risk factor for hip fractures and hip fracture pattern

Introduction: Osteoporosis and related fractures constitute a significant burden on modern healthcare. The standard method of diagnosing osteoporosis with a dual-energy X-ray absorptiometry (DXA) scan is limited by accessibility and expense. The thickness of the cortex of the proximal femur on plain radiographs has been suggested to be a method for indicating osteoporosis and as a risk factor of hip fractures in the elderly.

Methods: A retrospective study was undertaken to assess the usefulness of the canal-diaphysis ratio (CDR) as a risk factor for developing a hip fracture, excluding patients presenting under 50 years old, following high-energy trauma or pathological fractures. The CDR was measured in 84 neck of femur (NOF) fracture patients and 84 intertrochanteric hip fracture patients, and these were subsequently compared to the CDR of 84 patients without a hip fracture. Measurements were taken on two occasions by two members of the orthopaedic team, so as to assess the test’s inter- and intraobserver reliability.

Results: In comparison to those without a fracture, there was a significant difference in the CDR of patients with a NOF fracture (P < 0.0001) and intertrochanteric fracture (P < 0.0001). Furthermore, the odds of having a CDR above 60.67 and 64.41 were significantly higher in the NOF (OR = 2.214, P = 0.0129) and intertrochanteric fracture (OR = 32.27, P < 0.0001) groups respectively, when compared to the non-fractured group. The analysis of the test’s inter- and intraobserver reliability showed strong levels of reproducibility.

Discussion: We concluded that a raised CDR was associated with an increased incidence of NOF and intertrochanteric hip fracture. Measuring the CDR can thus be considered as a reproducible and inexpensive method of identifying elderly patients at risk of hip fractures.

Improving the Standard of Orthopaedic Operation Documentation Using Typed Proforma Operation Notes: A Completed Audit Loop

Introduction

The Royal College of Surgeons (RCS) published Good Surgical Practice guidelines in 2008 and revised them in 2014. They outline the basic standard that all surgical operation notes should meet.

Objectives

To retrospectively audit 57 typed orthopaedic operation notes from St. James’s Hospital in Dublin (from August to November 2015) against the RCS Good Surgical Practice guidelines published in 2014. They were then compared with the department’s previous audit of handwritten notes to complete the audit loop.

Materials and methods

A total of 57 orthopaedic operation notes were audited by a single reviewer. They were prospectively collected between August and November 2015. All notes were typed on the standard St. James’s Hospital operation note proforma.

Results

Of the surgeries, 89.5% were emergencies with 77.2% of them being performed by trainees. All of the operation notes were typed and signed by trainees. The procedure name, incision and closure details, tourniquet time (when relevant), and postoperative instructions were documented in 100% of the notes. In total, 80.7% had an operative diagnosis included while only 26.9% of the documentation had prosthesis serial numbers. All of the typed notes were deemed to be legible.

Conclusion

The use of printed operation notes allows for improved legibility when compared to typed notes. Documentation standards remained very high in the same areas as the handwritten notes and a marked improvement was seen in areas that had been poorly documented.

Total hip arthroplasty in patients with haemophilia - What are the risks of bleeding in the immediate peri-operative period?

BACKGROUND

Undergoing a major surgical intervention such as total hip arthroplasty (THA) with an underlying clotting disorder like haemophilia poses its own unique challenges. Despite the advances in factor replacement and medical management, the potential for excessive and uncontrolled haemorrhage still exists. The aim of this study was to quantify blood loss, peri-operative transfusion requirements and risk of haematoma formation in a cohort of patients with haemophilia undergoing THA.

METHODS

All patients with haemophilia types A or B who had undergone THA in the previous 10 years were identified from the Hospital In-Patient Enquiry system and theatre logs. A comprehensive review of operative records, laboratory parameters and peri-operative haematological management was conducted.

RESULTS

Eleven male patients (12 THA) were identified. The mean age was 56 years (range 28-76). The mean intra-operative blood loss was 502 ml (100-1250 ml) compared to an established normal blood loss of 400 ml. The mean drop in haemoglobin was 3.25 g/dl in 48 h. Only one patient required a post-operative transfusion of two units of red cell concentrate. There were no complications of haematoma formation.

CONCLUSION

The results in our institution compare favourably with the established blood loss reported in the literature and by assessment with International Guidelines. Average blood loss in patients with haemophilia was higher than the established normal, but there was no increased transfusion requirement.

A low-energy femoral shaft fracture from performing a yoga posture

The femoral shaft is rarely the site of a low-energy fracture in a healthy individual. The vast majority of these fractures are due to major trauma such as motor vehicle accidents. Although low-energy femoral shaft fractures do occur, they are typically in patients with osteoporotic bone, or prosthesis related. In this case report, we present a man in his late 30s who was practising a specific yoga stance when he experienced a femoral shaft fracture.

Unscheduled undergraduate teaching in surgery: a multi-institutional analysis

A significant amount of valuable undergraduate medical teaching may be informal, unscheduled and delivered by non-consultant hospital doctors (NCHDs). 800 Questionnaires were distributed to consultants, NCHDs and medical students in Irish teaching hospitals. The aim was to quantify the level of unscheduled teaching carried out in these hospitals and the manner in which it was performed. The response rate was 46% (364/800). 71% of doctors who replied are independently teaching undergraduate medical students (77/109), including 71% of interns and senior house officers (48/68). Students tend to prefer small group teaching. Fifty-six percent of students suggest they would benefit from more surgical teaching time (144/255). No interns surveyed were scheduled to teach as part of a formal curriculum. A significant amount of unscheduled teaching by interns and senior house officers takes place in Irish hospitals. It may prove beneficial to incorporate interns into scheduled surgical teaching curricula.

Exercise in the community for people with minimal gait impairment due to MS: an assessor-blind randomized controlled trial

Background:

While there is an increasing body of evidence supporting the efficacy of exercise in people with multiple sclerosis (MS), additional information on the effectiveness of combining aerobic and resistance training, and yoga is required.

Objectives:

This study evaluated the effectiveness of community exercise interventions for people with MS having minimal gait impairment.

Methods:

A multi-centred, block-randomised, assessor-blinded, controlled trial was conducted. Participants were randomised in groups of eight to physiotherapist (PT)-led exercise ( n = 80), yoga ( n = 77), fitness instructor (FI)-led exercise ( n = 86) and they took part in weekly community-based group exercise sessions. Those in the control group were asked not to change of their exercise habits ( n = 71). The primary outcome was the Multiple Sclerosis Impact Scale (MSIS) 29v2 physical component, measured before and after the 10-week intervention. Secondary outcomes were the MSIS 29v2 psychological component, the Modified Fatigue Impact Scale (MFIS) and the 6-Minute Walk Test (6MWT).

Results:

The group x time interaction approached significance for the MSIS-29v2 physical component ( f = 2.48, p = 0.061) and MFIS total ( f = 2.50, p = 0.06), and it was significant for the MFIS physical subscale ( f = 4.23, p = 0.006). All three exercise interventions led to a statistically significant improvement on the MSIS-29 psychological component and both the MFIS total and physical subscales, which were greater than the control ( p < 0.05). Only the PT-led and FI-led interventions significantly improved the MSIS-29 physical and 6MWT to levels greater than the control ( p < 0.05).

Conclusions:

This study provides evidence for the positive effect of exercise on the physical impact of MS and fatigue. The group nature of the classes may have contributed to the positive effects seen on the psychological impact of MS.

Learning, not adaptation, characterizes stroke motor recovery: evidence from kinematic changes induced by robot-assisted therapy in trained and untrained task in the same workspace

Both the American Heart Association and the VA/DoD endorse upper-extremity robot-mediated rehabilitation therapy for stroke care. However, we do not know yet how to optimize therapy for a particular patient's needs. Here, we explore whether we must train patients for each functional task that they must perform during their activities of daily living or alternatively capacitate patients to perform a class of tasks and have therapists assist them later in translating the observed gains into activities of daily living. The former implies that motor adaptation is a better model for motor recovery. The latter implies that motor learning (which allows for generalization) is a better model for motor recovery. We quantified trained and untrained movements performed by 158 recovering stroke patients via 13 metrics, including movement smoothness and submovements. Improvements were observed both in trained and untrained movements suggesting that generalization occurred. Our findings suggest that, as motor recovery progresses, an internal representation of the task is rebuilt by the brain in a process that better resembles motor learning than motor adaptation. Our findings highlight possible improvements for therapeutic algorithms design, suggesting sparse-activity-set training should suffice over exhaustive sets of task specific training.

Correction of severe hallux valgus using a basal chevron osteotomy and distal soft tissue release

BACKGROUND

There are many procedures described for the correction of severe hallux valgus. This is the first to examine the role of a basal osteotomy with distal soft tissue release.

METHODS

26 patients with severe hallux valgus underwent a basal chevron osteotomy with distal soft tissue release. All were reviewed at an average of 38 months.

RESULTS

The mean AOFAS score improved from 24 to 82 points (p<0.001). The IMA improved from an average of 23.90 to 130 (p<0.01). The HVA improved from an average of 490 to 170 (p<0.005). The correlation coefficient between the AOFAS score and various radiological angles was low (0.47).

CONCLUSIONS

Good clinical outcomes in cases of severe hallux valgus can be achieved without full restoration of normal radiological values. Furthermore, a basal chevron osteotomy with a distal soft tissue release offers a high satisfaction rating with regards to both clinical and functional outcomes in the short to medium-term.

LEVEL OF EVIDENCE

Level IV - Case series.

Non-monotonicity on a spatio-temporally defined cyclic task: evidence of two movement types?

We tested 23 healthy participants who performed rhythmic horizontal movements of the elbow. The required amplitude and frequency ranges of the movements were specified to the participants using a closed shape on a phase-plane display, showing angular velocity versus angular position, such that participants had to continuously control both the speed and the displacement of their forearm. We found that the combined accuracy in velocity and position throughout the movement was not a monotonic function of movement speed. Our findings suggest that specific combinations of required movement frequency and amplitude give rise to two distinct types of movements: one of a more rhythmic nature, and the other of a more discrete nature.

An open-label, single-arm study assessing safety and efficacy of panitumumab in patients with metastatic colorectal cancer refractory to standard chemotherapy

BACKGROUND

A phase 3 study demonstrated that panitumumab, a human monoclonal anti-epidermal growth factor receptor antibody, significantly prolonged progression-free survival versus best supportive care (BSC) in patients with chemorefractory metastatic colorectal cancer.

PATIENTS AND METHODS

This open-label extension study evaluated panitumumab monotherapy in BSC patients with radiographically documented disease progression in the phase 3 study. Patients received panitumumab 6 mg/kg every 2 weeks. The primary end point was safety; efficacy was also evaluated.

RESULTS

One hundred and seventy-six patients were randomly assigned to the BSC arm of the phase 3 study received >/=1 panitumumab dose in this extension study. Panitumumab was well tolerated. The most frequent treatment-related adverse events were skin toxic effects. Three (2%) patients had a grade 4 treatment-related adverse event. There were no infusion reactions. One (0.6%) patient had a complete response; 19 (11%) patients had a partial response; and 58 (33%) patients had stable disease. Median progression-free survival time was 9.4 [95% confidence interval (CI): 8.0-13.4) weeks. Median overall survival time was 6.3 (95% CI: 5.1-6.8) months. Anti-panitumumab antibodies were detected in 3 (4.2%) of 71 patients with a post-baseline sample.

CONCLUSIONS

These findings are comparable to those from the phase 3 study and support panitumumab monotherapy for chemorefractory colorectal cancer.

Design and Characterization of Hand Module for Whole-Arm Rehabilitation Following Stroke

In 1991, a novel robot named MIT-MANUS was introduced as a test bed to study the potential of using robots to assist in and quantify the neurorehabilitation of motor function. It introduced a new modality of therapy, offering a highly backdrivable experience with a soft and stable feel for the user. MIT-MANUS proved an excellent fit for shoulder and elbow rehabilitation in stroke patients, showing a reduction of impairment in clinical trials with well over 300 stroke patients. The greatest impairment reduction was observed in the group of muscles exercised. This suggests a need for additional robots to rehabilitate other target areas of the body. Previous work has expanded the planar MIT-MANUS to include an antigravity robot for shoulder and elbow, and a wrist robot. In this paper we present the "missing link": a hand robot. It consists of a single-degree-of-freedom (DOF) mechanism in a novel statorless configuration, which enables rehabilitation of grasping. The system uses the kinematic configuration of a double crank and slider where the members are linked to stator and rotor; a free base motor, i.e., a motor having two rotors that are free to rotate instead of a fixed stator and a single rotatable rotor (dual-rotor statorless motor). A cylindrical structure, made of six panels and driven by the relative rotation of the rotors, is able to increase its radius linearly, moving or guiding the hand of the patients during grasping. This module completes our development of robots for the upper extremity, yielding for the first time a whole-arm rehabilitation experience. In this paper, we will discuss in detail the design and characterization of the device.

Changing motor synergies in chronic stroke

Synergies are thought to be the building blocks of vertebrate movements. The inability to execute synergies in properly timed and graded fashion precludes adequate functional motor performance. In humans with stroke, abnormal synergies are a sign of persistent neurological deficit and result in loss of independent joint control, which disrupts the kinematics of voluntary movements. This study aimed at characterizing training-related changes in synergies apparent from movement kinematics and, specifically, at assessing: 1) the extent to which they characterize recovery and 2) whether they follow a pattern of augmentation of existing abnormal synergies or, conversely, are characterized by a process of extinction of the abnormal synergies. We used a robotic therapy device to train and analyze paretic arm movements of 117 persons with chronic stroke. In a task for which they received no training, subjects were better able to draw circles by discharge. Comparison with performance at admission on kinematic robot-derived metrics showed that subjects were able to execute shoulder and elbow joint movements with significantly greater independence or, using the clinical description, with more isolated control. We argue that the changes we observed in the proposed metrics reflect changes in synergies. We show that they capture a significant portion of the recovery process, as measured by the clinical Fugl-Meyer scale. A process of "tuning" or augmentation of existing abnormal synergies, not extinction of the abnormal synergies, appears to underlie recovery.

An improved acetabular cementing technique in total hip arthroplasty. Aspiration of the iliac wing

We have evaluated the effect of vacuum aspiration of the iliac wing on the osseointegration of cement into the acetabulum. We entered a total of 40 patients undergoing primary total hip arthroplasty into two consecutive study groups. Group 1 underwent acetabular cement pressurisation for 60 seconds before insertion of the acetabular component. Group 2 had the same pressurisation with simultaneous vacuum suction of the ilium using an iliac-wing aspirator. Standard post-operative radiographs were reviewed blindly to assess the penetration of cement into the iliac wing. Penetration was significantly greater in the group with aspiration of the iliac wing.

Robot-aided sensorimotor arm training improves outcome in patients with chronic stroke

Thirty patients with chronic stroke received 6 weeks of sensorimotor robotic training in a pilot study that targeted motor function of the affected shoulder and elbow. The impairment and disability scores were stable during a 2-month observation/measurement period, improved significantly by program completion, and remained robust in the 3-month follow-up. Task-specific motor training attenuated a chronic neurologic deficit well beyond the expected period for improvement after stroke.

Robot-aided neurorehabilitation: from evidence-based to science-based rehabilitation

There is no "magic bullet" in rehabilitation. In the absence of direct neural transplants, neurological rehabilitation is an arduous process. We have pioneered the clinical application of robotics in stroke rehabilitation and have shown evidence of the positive impact of targeted exercise on stroke recovery. In this article, we will review results obtained in the initial clinical trials with 96 stroke patients at the Burke Rehabilitation Hospital. We will provide evidence that robot-aided training enhances recovery, that this enhanced recovery is sustained in the long term, and that this recovery is not due to a general physiological improvement--in fact, it appears to be limb and muscle group specific. An evidence-based approach must now segue into a more scientific approach to stroke rehabilitation. Given the length of the required protocols and patients' variability and limited census, the practical limitations of the evidence-based approach are self-evident and extend trials for years. Each patient and lesion is unique in stroke rehabilitation, so there is no reason to believe that a "one-size-fits-all" optimal treatment exists. To optimize therapy for individual patients, we need science-based models. In this article, we will summarize the scientific tools and models that we are investigating and present some of the results to date.

Accuracy of clinical detection of INO in MS: Corroboration with quantitative infrared oculography

The authors compared the accuracy of clinical detection (by 279 physician observers) of internuclear ophthalmoparesis (INO) with that of quantitative infrared oculography. For the patients with mild adduction slowing, INO was not identified by 71%. Intermediate dysconjugacy was not detected by 25% of the evaluators. In the most severe cases, INO was not identified by only 6%. Oculographic techniques significantly enhance the precision of INO detection compared to the clinical exam.

Assessing the motor status score: a scale for the evaluation of upper limb motor outcomes in patients after stroke

The Motor Status Scale (MSS) measures shoulder, elbow (maximum score = 40), wrist, hand, and finger movements (maximum score = 42), and expands the measurement of upper extremity impairment and disability provided by the Fugl-Meyer (FM) score. This work examines the interrater reliability and criterion validity of the MSS performed in patients admitted to a rehabilitation hospital 21 +/- 4 days after stroke. Using the MSS and the FM, 7 occupational therapists masked to each other's judgments, evaluated 12 consecutive patients with stroke. Two therapists evaluated 6 additional patients on consecutive days. Intraclass correlation coefficients were significant for each group of raters for the shoulder/elbow and for the wrist/band (P < 0.0001); test-retest measures were also significant for the shoulder/elbow (Pearson correlation coefficient r = 0.99, P < 0.004) and for the wrist/hand (Pearson correlation coefficient r = 0.99, P < 0.003). The internal item consistency for the overall MSS was significant (Cronbach alpha = 0.98, P < 0.0001). Finally the correlation between the MSS and the FM (R2 = 0.964) was significant (P < 0.0001). The MSS affords a reliable and valid assessment of upper limb impairment and disability following stroke.

Procedural motor learning in Parkinson's disease

We have been investigating motor control and learning in parkinsonian subjects. In the current study, we sought to explore the existence of deficits in procedural motor learning, which is a form of implicit motor learning where skill improves over repetitive blocks of trials. We sought to determine, in particular, whether any such deficit is accentuated during specific types or phases of learning. We would expect that those specific learning tasks would require the greatest participation of the basal ganglia. Numerous studies have found that Parkinson's disease (PD) patients may show deficits in learning. Combined with information about basal ganglia neuronal connections and activity, this led some investigators to suggest that one of the key functions of the basal ganglia is to facilitate learning. To investigate these learning deficits, we used a robotic device to generate conservative force fields that disturbed the subjects' arm movements, thereby generating a "virtual mechanical environment" that subjects learned to manipulate. Movements were successively grouped into blocks comprising five different conditions: motor performance, early learning, late learning, negative transfer, and aftereffect motor performance. Our results with eight right-handed PD subjects and nine age-matched controls showed a relative decrease in the rate of learning for the PD patients in all blocks, but greater differences emerged between groups during novelty phases of learning. In particular, the difference in performance during the negative transfer condition reached statistical significance, suggesting that the basal ganglia might be a key center for "switching" motor patterns. Our results support the hypothesis that deficiencies in procedural motor learning are characteristic of PD. They add to existing evidence which has suggested a key role for the basal ganglia when new sensorimotor mappings are required by novel task environments. Better understanding of these deficits should facilitate the rehabilitation of PD patients.

Repeatability of maximal voluntary force and of surface EMG variables during voluntary isometric contraction of quadriceps muscles in healthy subjects

The repeatability of initial values and rate of change of EMG signal mean spectral frequency (MNF), average rectified values (ARV), muscle fiber conduction velocity (CV) and maximal voluntary contraction (MVC) was investigated in the vastus medialis obliquus (VMO) and vastus lateralis (VL) muscles of both legs of nine healthy male subjects during voluntary, isometric contractions sustained for 50 s at 50% MVC. The values of MVC were recorded for both legs three times on each day and for three subsequent days, while the EMG signals have been recorded twice a day for three subsequent days. The degree of repeatability was investigated using the Fisher test based upon the ANalysis Of VAriance (ANOVA), the Standard Error of the Mean (SEM) and the Intraclass Correlation Coefficient (ICC). Data collected showed a high level of repeatability of MVC measurement (normalized SEM from 1.1% to 6.4% of the mean). MNF and ARV initial values also showed a high level of repeatability (ICC>70% for all muscles and legs except right VMO). At 50% MVC level no relevant pattern of fatigue was observed for the VMO and VL muscles, suggesting that other portions of the quadriceps might have contributed to the generated effort. These observations seem to suggest that in the investigation of muscles belonging to a multi-muscular group at submaximal level, the more selective electrically elicited contractions should be preferred to voluntary contractions.

Dynamics of pushing

A standing individual can use several strategies for modulating pushing force magnitude. Using a static model, researchers have shown that the efficacy of those strategies varies considerably. In the present article, the authors propose a human motor control dynamic model for analyzing transients that occur when an individual is asked to modulate force magnitude. According to the model, the impedances of both the upper and the lower limbs influence the time course of force variations and foot placement has a profound effect on pushing force dynamics. With a feet-together posture, the center of pressure has a limited range of motion and changes in force may be preceded by initial changes in the opposite direction; that is, to decrease force, an individual must first increase force. When the feet are placed apart, individuals can move the center of pressure over a much larger range, thereby modulating pushing force magnitude, without reversing behavior, over a larger range of force magnitudes. Therefore, the best way to control pushing force at the hand may be by using the foot.

Is robot-aided sensorimotor training in stroke rehabilitation a realistic option?

Stroke is the leading cause of disability, despite continued advances in prevention and treatment techniques based on novel delivery of new fibrinolytic drugs. Improved medical treatment of the complications caused by acute stroke has contributed to decreased mortality, but 90% of the survivors have significant neurological deficits. Reducing the degree of permanent disability remains the goal of poststroke neuro-rehabilitation programs, and new approaches to impairment reduction through managing sensorimotor experience may contribute further to altering disability. Recent reports from a number of laboratories using enhanced sensorimotor training protocols, particularly those with robotic devices, have indicated modest success in reducing impairment and increasing motor power in the exercised limb of patients with stroke when compared with control individuals. Whether arming the therapist with new tools, especially robotic devices, to treat impairment is a realistic approach to modern interdisciplinary rehabilitation raises questions regarding the added value of impairment reduction, and under what conditions should scientific and clinical development of robotic studies continue.

Stability in force-production tasks

Exerting a force on a mechanical system can induce mechanical instability. To overcome that instability, humans may take advantage of their upper limb mechanical impedance (e.g., hand stiffness). The authors investigated what stiffness is required to maintain static stability and how humans can achieve that stiffness in the context of the task of pushing on a pivoting stick. Results showed that the stiffness required is in the range of measured human upper limb stiffness. To avoid an ill-posed problem, one can better express the requirements for stability as a simple geometrical criterion related to the curvature of the potential energy field at the hand. A planar model of the upper limb revealed that individuals can use both hand rotational and translational stiffness to stabilize a stick. Although hand rotational stiffness does not participate in producing the axial force on the stick, it can significantly contribute to achieving a limb stiffness appropriate for maintaining static stability. Hand rotational stiffness can be important for the design of hand tools, because humans can increase it only by augmenting grip force, a biomechanical factor associated with cumulative trauma injuries of the upper extremities.

Modulation and vectorial summation of the spinalized frog's hindlimb end-point force produced by intraspinal electrical stimulation of the cord

The ability to produce various force patterns at the ankle by microstimulation of the gray matter of the spinal cord was investigated in spinalized frogs. We evaluated the recruitment properties of individual spinal sites and found that forces increase linearly with activation level in the low-force range studied, while the structure of the force pattern remains invariant. We also measured the responses produced by coactivation of two spinal sites activated at two pairs of stimulation levels. Responses were measured at the mechanical level by recording forces at the ankle; and, at the muscular level by recording the electromyographic (EMG) activity of 11 hindlimb muscles. We found that for both pairs of activation, the forces under coactivation were the scaled vectorial summation of the individual responses. At the muscular level, rectified and integrated EMGs also summated during coactivation. Numerous force patterns could, thus, be created by the activation of a few individual sites. These results suggest that microstimulation of the circuitry of the spinal cord (higher order neurons than the motoneurons) holds promise as a new functional neuromuscular stimulation (FNS) technique for the restoration of multi-joint movements.

The influence of age on weight-bearing joint reposition sense of the knee

Knee joint-position sensitivity has been shown to decline with increasing age, with much of the research reported in the literature investigating this age effect in non-weight-bearing (NWB) conditions. However, little data is available in the more functional position of weight-bearing conditions. The objective of this study was to identify the influence of age on the accuracy and nature of knee joint-position sense (JPS) in both full weight-bearing (FWB) and partial weight-bearing (PWB) conditions and to determine the effect of lower-extremity dominance on knee JPS. Sixty healthy subjects from three age groups (young: 20-35 years old, middle-aged: 40-55 years, and older: 60-75 years) were assessed. Tests were conducted on both the right and left legs to examine the ability of subjects to correctly reproduce knee angles in an active criterion-active repositioning paradigm. Knee angles were measured in degrees using an electromagnetic tracking device, Polhemus 3Space Fastrak, that detected positions of sensors placed on the test limb. Errors in FWB knee joint repositioning did not increase with age, but significant age-related increases in knee joint-repositioning error were found in PWB. It was found that elderly subjects tended to overshoot the criterion angle more often than subjects from the young and middle-aged groups. Subjects in all three age groups performed better in FWB than in PWB. Differences between the stance-dominant (STD) and skill-dominant (SKD) legs did not reach significance. Results demonstrated that for, normal pain-free individuals, there is no age-related decline in knee JPS in FWB, although an age effect does exist in PWB. This outcome challenges the current view that a generalised decline in knee joint proprioception occurs with age. In addition, lower-limb dominance is not a factor in acuity of knee JPS.

Increasing productivity and quality of care: robot-aided neuro-rehabilitation

This paper presents an overview of our research in robot-aided stroke neuro-rehabilitation and recovery. At the onset of this research we had to confront squarely (and solve!) a critical question: If anatomy is destiny, can we influence it? Our efforts over the last five years have been focused on answering this question and we will present a few of our clinical results from over 2,000 hours of robot-aided therapy with 76 stroke patients. To determine if exercise therapy influences plasticity and recovery of the brain following a stroke, we needed the appropriate "microscope" that would allow us to concomitantly control the amount of therapy delivered to a patient, while objectively measuring patient's performance. Back-driveable robots are the key enabling technology. Our results to date using common clinical scales suggest that robot-aided sensorimotor training does have a genuinely positive effect on reduction of impairment and the reorganization of the adult brain. Yet while clinical scales can help us to examine the impact in the neuro-recovery process, their coarse nature requires extensive and time-consuming trials, and on top of that they fail to show us details important for optimizing therapy. Alternative, robot-based scales offer the potential benefit of new finer measurements-and deeper insight into the process of recovery from neurological injury. We also plan to use present technology to establish the practicality and economic feasibility of clinician-supervised, robot-administered therapy, including classroom therapy. We feel quite optimistic that the march of progress will accelerate substantially in the near future and allow us to transfer this technology from the research realm to the everyday treatment of stroke survivors.

Robot-aided functional imaging: application to a motor learning study

The purpose of this study was to examine the neural activity underlying an implicit motor learning task. In particular, our goals were to determine whether initial phases of procedural learning of a motor task involve areas of the brain distinct from those involved in later phases of learning the task, and what changes in neural activity coincide with performance improvement. We describe a novel integration of robotic technology with functional brain imaging and its use in this study of implicit motor learning. A portable robotic device was used to generate forces that disturbed the subjects' arm movements, thereby generating a "virtual mechanical environment" that the subjects learned to manipulate. Positron emission tomography (PET) was used to measure indices of neural activity underlying learning of the motor task. Eight health, right-handed male subjects participated in the study. Results support the hypothesis that different stages of implicit learning (early and late implicit learning) occur in an orderly fashion, and that distinct neural structures may be involved in these different stages. In particular, neuroimaging results indicate that the cortico-striatal loop may play a significant role during early learning, and that the cortico-cerebellar loop may play a significant role during late learning.