Richmond Hospital

The concept of depth from focus involves calculating distances to points in an observed scene by modeling the effect that the camera's focal parameters have on images acquired with a small depth of field. This technique is passive and requires only a single camera. The most difficult segment of calculating depth from focus is deconvolving the defocus operator from the scene and modeling it. Most current methods for determining the defocus operator employ inverse filtering. The authors reveal some fundamental problems with inverse filtering: inaccuracies in finding the frequency domain representation, windowing effects, and border effects. A general, matrix-based method using regularization is presented, which eliminates these problems. The new method is confirmed experimentally, with the results showing an RMS error of 1.3%.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

OBJECTIVE: To develop a theoretical framework of youth empowerment in the context of a participatory community health promotion intervention, a longitudinal qualitative study was conducted. METHODS: Individual and group interviews, documents, and observations were analyzed using the constant comparative method and theoretical sampling. RESULTS: Practitioners created an environment conducive to adolescents' taking responsibility for their quality-of-life issues by welcoming and enabling youth. Power was transferred to youth as responsibility for voicing, decision making, and action. This led to positive changes in youth development and their social integration into community. CONCLUSION: Empowerment emerged as a transactional partnering process between adults and youth.

INTRODUCTION: Data are sparse as to whether obesity influences the risk of death in critically ill patients with septic shock. We sought to examine the possible impact of obesity, as assessed by body mass index (BMI), on hospital mortality in septic shock patients. METHODS: We performed a nested cohort study within a retrospective database of patients with septic shock conducted in 28 medical centers in Canada, United States and Saudi Arabia between 1996 and 2008. Patients were classified according to the World Health Organization criteria for BMI. Multivariate logistic regression analysis was performed to evaluate the association between obesity and hospital mortality. RESULTS: Of the 8,670 patients with septic shock, 2,882 (33.2%) had height and weight data recorded at ICU admission and constituted the study group. Obese patients were more likely to have skin and soft tissue infections and less likely to have pneumonia with predominantly Gram-positive microorganisms. Crystalloid and colloid resuscitation fluids in the first six hours were given at significantly lower volumes per kg in the obese and very obese patients compared to underweight and normal weight patients (for crystalloids: 55.0 ± 40.1 ml/kg for underweight, 43.2 ± 33.4 for normal BMI, 37.1 ± 30.8 for obese and 27.7 ± 22.0 for very obese). Antimicrobial doses per kg were also different among BMI groups. Crude analysis showed that obese and very obese patients had lower hospital mortality compared to normal weight patients (odds ratio (OR) 0.80, 95% confidence interval (CI) 0.66 to 0.97 for obese and OR 0.61, 95% CI 0.44 to 0.85 for very obese patients). After adjusting for baseline characteristics and sepsis interventions, the association became non-significant (OR 0.80, 95% CI 0.62 to 1.02 for obese and OR 0.69, 95% CI 0.45 to 1.04 for very obese). CONCLUSIONS: The obesity paradox (lower mortality in the obese) documented in other populations is also observed in septic shock. This may be related in part to differences in patient characteristics. However, the true paradox may lie in the variations in the sepsis interventions, such as the administration of resuscitation fluids and antimicrobial therapy. Considering the obesity epidemic and its impact on critical care, further studies are warranted to examine whether a weight-based approach to common therapeutic interventions in septic shock influences outcome.

We describe an operative approach to lumbar canal stenosis which, unlike laminectomy, takes into account the segmental pathology of the disease. At each level involved, a bilateral subarticular fenestration is performed under high magnification. The medial third of each facet joint is first removed with an air-powered drill; then the remaining two-thirds of the joint is undercut with the drill to allow a generous fenestration in the thickened ligamentum flavum and adjacent laminae. All tissue responsible for neural compression is removed, but the spinous processes, interspinous ligaments, and much of the facet joints and laminae are preserved. Spinal stability is maintained and, because tissue disruption is minimized, postoperative discomfort is usually reduced, promoting early mobility and reduced hospital stay. The operation is described in detail, and the results of operation in 32 patients are assessed. The follow-up periods now range from 17 to 58 months. Of 23 patients who presented with neurogenic claudication, 14 (61%) obtained complete relief and 7 (30%) improved significantly. The mean hospital stay was 9 days (range, 4 to 17 days).

Most North American universities offer sexual assault prevention programs focusing on attitude change. However, the few program outcome evaluations suggest that these programs may not be effective. This review summarizes the research on sexual assault program evaluation. It is apparent that the most promising avenue for sexual assault prevention may be self-defense training, which is presently not an integral component of typical prevention programs. The substantial body of research on risk factors for sexual assault is also reviewed, and it is concluded that existing rape prevention programs could be improved by focusing on these factors.

OBJECTIVE: The objective of this study was to compare the headache impact test (HIT-6) and the migraine disability assessment scale (MIDAS) as clinical measures of headache-related disability. BACKGROUND: The degree of headache-related disability is an important factor in treatment planning. Many quality of life and headache disability measures exist but it is unclear which of the available disability measures is the most helpful in planning and measuring headache management. METHODS: We compared HIT-6 and MIDAS scores from 798 patients from the Canadian Headache Outpatient Registry and Database (CHORD). Correlation and regression analyses were used to examine the relationships between the HIT-6 and MIDAS total scores, headache frequency and intensity, and Beck Depression Inventory (BDI-II) scores. RESULTS: A positive correlation was found between HIT-6 and MIDAS scores (r = 0.52). The BDI-II scores correlated equally with the HIT-6 and the MIDAS (r = 0.42). There was a non-monotonic relationship between headache frequency and the MIDAS, and a non-linear monotonic relationship between headache frequency and the HIT-6 (r = 0.24). The correlation was higher between the intensity and the HIT-6 scores (r = 0.46), than MIDAS (r = 0.26) scores. Seventy-nine percent of patients fell into the most severe HIT-6 disability category, compared with the 57% of patients that fell into the most severe MIDAS disability category. Significantly more patients were placed in a more severe category with the HIT-6 than with the MIDAS (McNemar chi-square = 191 on 6 d.f., P < .0001). CONCLUSIONS: The HIT-6 and MIDAS appear to measure headache-related disability in a similar fashion. However, some important differences may exist. Headache intensity appears to influence HIT-6 score more than the MIDAS, whereas the MIDAS was influenced more by headache frequency. Using the HIT-6 and MIDAS together may give a more accurate assessment of a patient's headache-related disability.

OBJECTIVE: The use of antibacterial agents to clean and dry the stump of the newborn's umbilical cord after birth has recently been abandoned by many neonatal units in favor of dry cord care. The objective of this study was to compare cord bacterial colonization and morbidity among newborns whose cords were treated with triple dye and alcohol versus dry cord care. METHODOLOGY: We randomly allocated 766 newborns to either 2 applications of triple dye to the umbilical cord stump on the day of birth with alcohol swabbing twice daily until the cord fell off (n = 384) or dry care (n = 382). Dry care consisted of spot cleaning soiled skin in the periumbilical area with soap and water, wiping it with a dry cotton swab or cloth, and allowing the area to air dry. Umbilical stumps on all subjects were swabbed and cultured. Community health nurses visiting at 2 or 3 days after hospital discharge observed the stump for signs of infection. Follow-up phone calls were made to mothers within 3 weeks of discharge. RESULTS: One infant in the dry care group was diagnosed with omphalitis. The umbilical stump was colonized with alpha-hemolytic streptococcus and coagulase-negative staphylococcus. Infants in the dry care group were significantly more likely to be colonized with Escherichia coli (34.2% vs 22.1%), coagulase-negative staphylococci (69.5% vs 50.5%), Staphylococcus aureus (31.3% vs 2.8%), and group B streptococci (11.7% vs 6.0%). Community health nurses were significantly more likely to observe exudate (7.4% vs 0.3%) and foul odor (2.9% vs 0.7%) among infants allocated to the dry care group during the home visit. CONCLUSIONS: Omphalitis remains a clinical issue. Cessation of bacteriocidal care of the umbilical stump must be accompanied by vigilant attention to the signs and symptoms of omphalitis.

This paper presents a strategy for scaling climate change adaptation within urban areas. The strategy specifically focuses on the requirements for mobilizing large amounts of capital for adaptation and other urban risk reduction above and beyond the amounts that will likely be mobilized through new international adaptation funds. The paper, based on a report published by ICLEI–Local Governments for Sustainability, ( 1 ) proposes a re-framing of the urban adaptation and disaster reduction challenge. The approach shifts the adaptation focus from risk reduction as a primary end in itself to a broader development focus on financing the performance of urban assets, areas and/or systems. This emphasis is elaborated through the concept of “resilience”, an urban design and investment metric that measures the ability of urban areas and their individual assets to perform for users and their investors under a wide range of conditions. The paper argues that such a performance-oriented approach provides a business logic that can attract conventional, private investment flows to climate and disaster risk reduction measures and thereby “mainstream” them.

PURPOSE: Robotically-assisted total knee arthroplasty (TKA) has been shown to improve alignment and decrease outliers, an important goal in TKA procedures. The purpose of this cadaveric study was to compare the accuracy and reproducibility of a recently introduced TKA robotic system to conventional instrumentation for bone resections. METHODS: This cadaveric study compared 14 robotically-assisted TKA with 20 conventional TKAs. Four board-certified high volume arthroplasty surgeons with no prior experience in robotics (except one) performed the procedures with three different implant systems. Angle and level of bone resections obtained from optical navigation or calliper measurements were compared to the intra-operative plan to determine accuracy. Group comparison was performed using Student t test (mean) and F test (variance), with significance at p < 0.05. RESULTS: The robotic group demonstrated statistically more accurate results (p < 0.05) and fewer outliers (p < 0.05) than conventional instrumentation when aiming for neutral alignment. Final limb alignment (HKA) had an accuracy of 0.8° ± 0.6° vs 2.0° ± 1.6°, with 100% vs 75% of cases within 3° and 93% vs 60% within 2°. For the robotically-assisted knees, the accuracy of bone resection angles was below 0.6° with standard deviations below 0.4°, except for the femur flexion (1.3° ± 1.0°), and below 0.7 mm with standard deviations below 0.7 mm for bone resection levels. CONCLUSION: This in vitro study has demonstrated that this novel TKA robotic system produces more accurate and more reproducible bone resections than conventional instrumentation. It supports the clinical use of this new robotic system. LEVEL OF EVIDENCE: Cadaveric study, Level V.

OBJECTIVES: Bronchiolitis is an acute, highly communicable lower respiratory tract infection. Bronchodilators are commonly used in the management of bronchiolitis in North America, but not in the United Kingdom. The objective of this review was to assess the effects of bronchodilators for bronchiolitis. SEARCH STRATEGY: We searched MEDLINE, EMBASE, Reference Update, reference lists of articles, and the files of two of the authors up to June 1998. SELECTION CRITERIA: Randomised trials comparing bronchodilators with placebo in the treatment of bronchiolitis. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial quality and extracted data. Unpublished data were requested from authors when necessary. MAIN RESULTS: In eight trials with 394 children, 46% demonstrated an improved clinical score with bronchodilators compared to 75% with placebo (odds ratio for no improvement 0.29, 95% confidence interval 0.19 to 0.45). However, the inclusion of studies that enrolled people with recurrent wheezes may have biased these results in favour of bronchodilators. Bronchodilator recipients did not show improvement in measures of oxygenation, the rate of hospitalisation (18% versus 26%, odds ratio 0.70, 95% confidence interval 0.36 to 1.35) or duration of hospitalisation (weighted mean difference 0.12, 95% confidence interval -0.3 to 0.5). REVIEWER'S CONCLUSIONS: Bronchodilators produce modest short-term improvement in clinical scores. This small benefit must be weighed against the costs of these agents.

Importance: Proper evaluation of the performance of artificial intelligence techniques in the analysis of digitized medical images is paramount for the adoption of such techniques by the medical community and regulatory agencies. Objectives: To compare several cross-validation (CV) approaches to evaluate the performance of a classifier for automatic grading of prostate cancer in digitized histopathologic images and compare the performance of the classifier when trained using data from 1 expert and multiple experts. Design, Setting, and Participants: This quality improvement study used tissue microarray data (333 cores) from 231 patients who underwent radical prostatectomy at the Vancouver General Hospital between June 27, 1997, and June 7, 2011. Digitized images of tissue cores were annotated by 6 pathologists for 4 classes (benign and Gleason grades 3, 4, and 5) between December 12, 2016, and October 5, 2017. Patches of 192 µm2 were extracted from these images. There was no overlap between patches. A deep learning classifier based on convolutional neural networks was trained to predict a class label from among the 4 classes (benign and Gleason grades 3, 4, and 5) for each image patch. The classification performance was evaluated in leave-patches-out CV, leave-cores-out CV, and leave-patients-out 20-fold CV. The analysis was performed between November 15, 2018, and January 1, 2019. Main Outcomes and Measures: The classifier performance was evaluated by its accuracy, sensitivity, and specificity in detection of cancer (benign vs cancer) and in low-grade vs high-grade differentiation (Gleason grade 3 vs grades 4-5). The statistical significance analysis was performed using the McNemar test. The agreement level between pathologists and the classifier was quantified using a quadratic-weighted κ statistic. Results: On 333 tissue microarray cores from 231 participants with prostate cancer (mean [SD] age, 63.2 [6.3] years), 20-fold leave-patches-out CV resulted in mean (SD) accuracy of 97.8% (1.2%), sensitivity of 98.5% (1.0%), and specificity of 97.5% (1.2%) for classifying benign patches vs cancerous patches. By contrast, 20-fold leave-patients-out CV resulted in mean (SD) accuracy of 85.8% (4.3%), sensitivity of 86.3% (4.1%), and specificity of 85.5% (7.2%). Similarly, 20-fold leave-cores-out CV resulted in mean (SD) accuracy of 86.7% (3.7%), sensitivity of 87.2% (4.0%), and specificity of 87.7% (5.5%). Results of McNemar tests showed that the leave-patches-out CV accuracy, sensitivity, and specificity were significantly higher than those for both leave-patients-out CV and leave-cores-out CV. Similar results were observed for classifying low-grade cancer vs high-grade cancer. When trained on a single expert, the overall agreement in grading between pathologists and the classifier ranged from 0.38 to 0.58; when trained using the majority vote among all experts, it was 0.60. Conclusions and Relevance: Results of this study suggest that in prostate cancer classification from histopathologic images, patch-wise CV and single-expert training and evaluation may lead to a biased estimation of classifier's performance. To allow reproducibility and facilitate comparison between automatic classification methods, studies in the field should evaluate their performance using patient-based CV and multiexpert data. Some of these conclusions may be generalizable to other histopathologic applications and to other applications of machine learning in medicine.

Context Feral cats (Felis catus) threaten biodiversity in many parts of the world, including Australia. Low-level culling is often used to reduce their impact, but in open cat populations the effectiveness of culling is uncertain. This is partly because options for assessing this management action have been restricted to estimating cat activity rather than abundance. Aims We measured the response, including relative abundance, of feral cats to a 13-month pulse of low-level culling in two open sites in southern Tasmania. Methods To do this we used remote cameras and our analysis included identification of individual feral cats. We compared estimates of relative abundance obtained via capture–mark–recapture and minimum numbers known to be alive, and estimates of activity obtained using probability of detection and general index methods, pre- and post-culling. We also compared trends in cat activity and abundance over the same time period at two further sites where culling was not conducted. Key results Contrary to expectation, the relative abundance and activity of feral cats increased in the cull-sites, even though the numbers of cats captured per unit effort during the culling period declined. Increases in minimum numbers of cats known to be alive ranged from 75% to 211% during the culling period, compared with pre- and post-cull estimates, and probably occurred due to influxes of new individuals after dominant resident cats were removed. Conclusions Our results showed that low-level ad hoc culling of feral cats can have unwanted and unexpected outcomes, and confirmed the importance of monitoring if such management actions are implemented. Implications If culling is used to reduce cat impacts in open populations, it should be as part of a multi-faceted approach and may need to be strategic, systematic and ongoing if it is to be effective.

Synovial membranes from 54 dogs were collected at the time of surgery to stabilize the stifle joint following rupture of the cranial cruciate ligament. Histological evaluation revealed lymphoplasmacytic synovitis with the formation of distinct, nodular aggregates in 36 synovial membranes. The remainder had evidence of chronic synovitis with variable numbers of diffuse, mononuclear cells. The presence of a potentially immune-mediated synovitis in the majority of cases suggests the need for further study.

OBJECTIVE: The Health of Nation Outcome Scales (HoNOS) was developed to assess mental health outcomes. The aim of the studies is to examine the psychometric properties, reliability and validity of the HoNOS. METHOD: Three studies were conducted within St John of God Hospitals in New South Wales, Australia. They examined the reliability and the validity of the HoNOS. The first study examined the interrater reliability of the HoNOS, before and after staff training in the use of the HoNOS. The second study examined the validity of the HoNOS with the Symptom Checklist 90 Revised (SCL90-R) and the third study examined the validity of the HoNOS with the Short-Form 36 (SF-36). RESULTS: The first study showed an improvement in the interrater reliability (IRR) of the HoNOS due to training. However, a generally unsatisfactory IRR (range 0.50-0.65) was achieved. The second study found no correlation between the SCL90-R and the HoNOS on admission (r = 0.04) and discharge (r = 0.06). The third study found no significant correlation between the Mental Component Score of the SF-36 and the HoNOS on admission (r = -0.033) nor on discharge (r = -0.104). CONCLUSIONS: The HoNOS has at best moderate interrater reliabilities. Further, the validity of the HoNOS is under question, that is, it does not correlate with a major measure of mental health symptoms, nor with a major measure of health status. As such, it is concluded that the psychometric properties of the HoNOS do not warrant its use as a routine measure.

INTRODUCTION: The coronavirus 2019 disease (COVID-19) pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Pre-existing cardiovascular disease (CVD) increases the morbidity and mortality of COVID-19, and COVID-19 itself causes serious cardiac sequelae. Strategies to minimise the risk of viral transmission to health care workers and uninfected cardiac patients while prioritising high quality cardiac care are urgently needed. We conducted a rapid literature appraisal and review of key documents identified by the Cardiac Society of Australia and New Zealand Board and Council members, the Australian and New Zealand Society of Cardiac and Thoracic Surgeons, and key cardiology, surgical and public health opinion leaders. MAIN RECOMMENDATIONS: Common acute cardiac manifestations of COVID-19 include left ventricular dysfunction, heart failure, arrhythmias and acute coronary syndromes. The presence of underlying CVD confers a five- to tenfold higher case fatality rate with COVID-19 disease. Special precautions are needed to avoid viral transmission to this population at risk. Adaptive health care delivery models and resource allocation are required throughout the health care system to address this need. CHANGES IN MANAGEMENT AS A RESULT OF THIS STATEMENT: Cardiovascular health services and cardiovascular health care providers need to recognise the increased risk of COVID-19 among CVD patients, upskill in the management of COVID-19 cardiac manifestations, and reorganise and innovate in service delivery models to meet demands. This consensus statement, endorsed by the Cardiac Society of Australia and New Zealand, the Australian and New Zealand Society of Cardiac and Thoracic Surgeons, the National Heart Foundation of Australia and the High Blood Pressure Research Council of Australia summarises important issues and proposes practical approaches to cardiovascular health care delivery to patients with and without SARS-CoV-2 infection.

BACKGROUND: High-income countries like Australia play a vital role in resettling refugees from around the world, half of whom are children and adolescents. Informed by an ecological framework, this study examined the post-migration adjustment of refugee children and adolescents 2-3 years after arrival to Australia. We aimed to estimate the overall rate of adjustment among young refugees and explore associations with adjustment and factors across individual, family, school, and community domains, using a large and broadly representative sample. METHODS: Data were drawn from Wave 3 of the Building a New Life in Australia (BNLA) study, a nationally representative, longitudinal study of settlement among humanitarian migrants in Australia. Caregivers of refugee children aged 5-17 (N = 694 children and adolescents) were interviewed about their children's physical health and activity, school absenteeism and achievement, family structure and parenting style, and community and neighbourhood environment. Parent and child forms of the Strengths and Difficulties Questionnaire (SDQ) were completed by caregivers and older children to assess social and emotional adjustment. RESULTS: Sound adjustment according to the SDQ was observed regularly among young refugees, with 76-94% (across gender and age) falling within normative ranges. Comparison with community data for young people showed that young refugees had comparable or higher adjustment levels than generally seen in the community. However, young refugees as a group did report greater peer difficulties. Bivariate and multivariate linear regression analyses showed that better reported physical health and school achievement were associated with higher adjustment. Furthermore, higher school absenteeism and endorsement of a hostile parenting style were associated with lower adjustment. CONCLUSIONS: This is the first study to report on child psychosocial outcomes from the large, representative longitudinal BNLA study. Our findings indicate sound adjustment for the majority of young refugees resettled in Australia. Further research should examine the nature of associations between variables identified in this study. Overall, treating mental health problems early remains a priority in resettlement. Initiatives to enhance parental capability, physical health, school achievement and participation could assist to improve settlement outcomes for young refugees.

OBJECTIVE: To report three cases of serum sickness-like reaction (SSLR) associated with bupropion ingestion. CASE SUMMARY: A 27-year-old woman, a 46-year-old man, and a 43-year-old woman presented to our emergency department within a three-week period with symptoms consistent with SSLR. Symptoms consisted of pruritic skin rash, tongue swelling, and arthralgias. All three patients had initiated bupropion therapy within two to three weeks prior to arrival. DISCUSSION: This is the second published case describing SSLRs associated with bupropion. Reports of urticaria and rash with bupropion use are numerous and the incidence has been estimated at between 1% and 4%. Arthralgia and arthropathy with bupropion use are reported much less commonly. The onset of symptoms of SSLRs typically begins six to 21 days after administration of the causative agent. SSLRs are usually self-limiting, lasting four to 14 days. CONCLUSIONS: SSLRs following bupropion ingestion appear to be rare. However, the fact that this cluster of patients presented to our emergency department within a three-week period suggests that this reaction may be underreported.

BACKGROUND: Although perceived social support is thought to be a strong predictor of psychological outcomes following trauma exposure, the temporal relationship between perceived positive and negative social support and post-traumatic stress disorder (PTSD) symptoms has not been empirically established. This study investigated the temporal sequencing of perceived positive social support, perceived negative social support, and PTSD symptoms in the 6 years following trauma exposure among survivors of traumatic injury. METHOD: Participants were 1132 trauma survivors initially assessed upon admission to one of four Level 1 trauma hospitals in Australia after experiencing a traumatic injury. Participants were followed up at 3 months, 12 months, 24 months, and 6 years after the traumatic event. RESULTS: Latent difference score analyses revealed that greater severity of PTSD symptoms predicted subsequent increases in perceived negative social support at each time-point. Greater severity of PTSD symptoms predicted subsequent decreases in perceived positive social support between 3 and 12 months. High levels of perceived positive or negative social support did not predict subsequent changes in PTSD symptoms at any time-point. CONCLUSIONS: Results highlight the impact of PTSD symptoms on subsequent perceived social support, regardless of the type of support provided. The finding that perceived social support does not influence subsequent PTSD symptoms is novel, and indicates that the relationship between PTSD and perceived social support may be unidirectional.

Obesity-associated visceral adipose tissue (AT) inflammation promotes insulin resistance and type 2 diabetes (T2D). In mice, lean visceral AT is populated with anti-inflammatory cells, notably regulatory T cells (Tregs) expressing the IL-33 receptor ST2. Conversely, obese AT contains fewer Tregs and more proinflammatory cells. In humans, however, there is limited evidence for a similar pattern of obesity-associated immunomodulation. We used flow cytometry and mRNA quantification to characterize human omental AT in 29 obese subjects, 18 of whom had T2D. Patients with T2D had increased proportions of inflammatory cells, including M1 macrophages, with positive correlations to body mass index. In contrast, Treg frequencies negatively correlated to body mass index but were comparable between T2D and non-T2D individuals. Compared to human thymic Tregs, omental AT Tregs expressed similar levels of FOXP3, CD25, IKZF2, and CTLA4, but higher levels of PPARG, CCR4, PRDM1, and CXCL2. ST2, however, was not detectable on omental AT Tregs from lean or obese subjects. This is the first comprehensive investigation into how omental AT immunity changes with obesity and T2D in humans, revealing important similarities and differences to paradigms in mice. These data increase our understanding of how pathways of immune regulation could be targeted to ameliorate AT inflammation in humans.

OBJECTIVE: To evaluate the functional outcomes and long-term effects on muscle strength of femoral shaft fractures treated with intramedullary (IM) antegrade nailing using a standard piriformis start point. DESIGN: Retrospective Outcome Study. SETTING: Tertiary Level Teaching Hospital and Referral Centre for the Province of British Columbia. PATIENTS/PARTICIPANTS: Twenty-one patients (7 female, 14 male; mean age 34.5 years, range 16-56 years) with isolated femoral shaft fractures who were treated with standard antegrade reamed interlocking IM nailing and who had a minimum 1-year follow-up were identified through the Orthopaedic Trauma Database. All patients had isokinetic muscle testing of their hip abductors, hip extensors, and knee extensors using the KinCom muscle testing machine. Of the patients, 10 underwent formal gait lab analysis. All of the patients answered a questionnaire and completed the Short Form (SF)-36 and Musculoskeletal Functional Assessment outcome measures. INTERVENTION: Antegrade reamed interlocking IM nailing of femoral shaft fractures using a standard trochanteric fossa (also referred to as piriformis fossa) starting point. MAIN OUTCOME MEASUREMENTS: Examination of muscle strength, using 2 different objective measures (KinCom and gait analysis). The KinCom muscle testing machine was used for isokinetic muscle testing of hip abductors, hip extensors, and knee extensors. Outcome questionnaires were used to evaluate function (Musculoskeletal Functional Assessment) and general health (SF-36). RESULTS: Isokinetic muscle testing showed a statistically significant lower peak torque generation by the hip abductors (P=0.003) and hip extensors (P=0.046) from the uninjured contralateral side. The gait lab analysis did not show important changes in gait pattern. Scores for the SF-36 were 51.77+/-7.55 and 53.73+/-8.70. Scores for the Short Musculoskeletal Functional Assessment (S-MFA) were 7.74 and 8.66. Both scores did not indicate any significant disability. CONCLUSIONS: Antegrade reamed interlocking IM nailing of femoral shaft fractures using a standard trochanteric fossa starting point is associated with a mild hip abductor muscle-strength deficit. Gait pattern returns to normal following femoral shaft fracture treated with this technique, and functional outcomes are good.