Long-term results of a rotationally unconstrained fixed-bearing total knee prosthesis.

PURPOSE: Introduced in the market in 1990 by Ceraver (France), the posterior-stabilised (PS) Hermes prosthesis has limited literature regarding long-term survivability. The purpose of the study is to evaluate the survival and functional outcomes of the prosthesis. METHODS: A retrospective case series was performed including 164 patients (176 knees) having undergone total knee arthroplasty with the Hermes prosthesis between 1997 and 2000 with a follow-up period of 18 years. RESULTS: Kaplan-Meier analysis showed a survival rate of 99.4% (95% CI. 96.0-100.0%) at 18.4 years with one revision. At final follow-up, the International Knee Society (IKS) functional score was 93.2 ± 15.6 and IKS knee score was 99.1 ± 2.5. CONCLUSION: The Hermes PS model is a low conformity prosthesis that offers reliable durability that is comparable to other popular designs while minimizing rotational constraints and having an approachable learning curve for new users.

Novel approach to analysis of the immune system using an ungated model of immune surface marker abundance to predict health outcomes.

Traditionally, the immune system is understood to be divided into discrete cell types that are identified via surface markers. While some cell type distinctions are no doubt discrete, others may in fact vary on a continum, and even within discrete types, differences in surface marker abundance could have functional implications. Here we propose a new way of looking at immune data, which is by looking directly at the values of the surface markers without dividing the cells into different subtypes. To assess the merit of this approach, we compared it with manual gating using cytometry data from the Singapore Longitudinal Aging Study (SLAS) database. We used two different neural networks (one for each method) to predict the presence of several health conditions. We found that the model built using raw surface marker abundance outperformed the manual gating one and we were able to identify some markers that contributed more to the predictions. This study is intended as a brief proof-of-concept and was not designed to predict health outcomes in an applied setting; nonetheless, it demonstrates that alternative methods to understand the structure of immune variation hold substantial progress.

Determinants of parents' decision to vaccinate their children against rotavirus: results of a longitudinal study.

Rotavirus disease is a common cause of health care utilization and almost all children are affected by the age of 5 years. In Canada, at the time of this survey (2008-09), immunization rates for rotavirus were <20%. We assessed the determinants of a parent's acceptance to have their child immunized against rotavirus. The survey instruments were based on the Theory of Planned Behavior. Data were collected in two phases. In all, 413 and 394 parents completed the first and second interviews, respectively (retention rate 95%). Most parents (67%) intended to immunize their child against rotavirus. Factors significantly associated with parental intentions (Phase 1) were as follows: perception of the moral correctness of having their child immunized (personal normative belief) and perception that significant others will approve of the immunization behavior (subjective norm), perceived capability of having their child immunized (perceived behavioral control) and household income. At Phase 2, 165 parents (42%) reported that their child was immunized against rotavirus. The main determinant of vaccination behavior was parental intention to have their child vaccinated, whereas personal normative beliefs influenced both intention and behavior. The acceptability of the rotavirus vaccine will be higher if health promotion addresses parental knowledge, attitudes and beliefs regarding the disease and the vaccine.

Selective anteromedial bundle reconstruction in partial ACL tears: a series of 36 patients with mean 24 months follow-up.

The purpose of this study was to describe an original technique of reconstruction of the anteromedial bundle preserving the posterolateral bundle and to report the results of a consecutive 36 patients series with mean 24 months follow-up. Our hypothesis is that this selective reconstruction of ACL partial tears could restore knee stability and function. In a consecutive series of 256, ACL reconstructions, 36 patients in which intact ACL fibers remained in the location corresponding to the posterolateral bundle were perioperatively diagnosed. These patients (21 women and 15 men) underwent isolated reconstruction of the anteromedial bundle while keeping the remaining fibers intact. AM bundle reconstructions were performed by the same surgeon using an outside-in technique. A quadrupled hamstring graft was used in 20 patients and a doubled semitendinosus graft in 16 patients. The mean age of the patients at the time of surgery was 32 years (min 15, max 53). The delay between injury and surgery was 6.6 months (min 2, max 35). Patients were assessed with the IKDC ligament evaluation form. Instrumented knee testing was performed with the Rolimeter arthrometer. Statistical analysis was performed to compare the preoperative and postoperative objective evaluation. Eleven concomitant meniscal lesions at the time of reconstruction were found. One patient who underwent a traumatic graft rupture at 4 months post surgery and two patients with previous contralateral ACL reconstruction were excluded, leaving 33 patients for final evaluation. Three reoperations were performed, including two arthrolysis for cyclops syndrome and one revision for a traumatic graft rupture. At last follow-up, 24 (73%) patients were graded A, 8 (24%) graded B and 1 C (3%) at IKDC objective evaluation. Mean side to side instrumented laxity was 4.8 mm (min 3, max 6) preoperatively and 0.8 mm (min 0, max 2) postoperatively. AM bundle reconstruction with an outside-in technique remains simple and reproducible. The preliminary results are encouraging with excellent side to side laxity. Graft size should probably be adapted to limit cyclops syndrome occurrence.

Rotational laxity greater in patients with contralateral anterior cruciate ligament injury than healthy volunteers.

Rotational stability of the knee has been traditionally difficult to quantify, limiting the ability of the orthopedic community to determine the potential role of rotational laxity in the etiology of anterior cruciate ligament (ACL) injuries. The purposes of this multicenter cohort study were to evaluate the reliability of a robotic axial rotation measurement system, determine whether the uninjured knees of patients that had previous contralateral ACL reconstruction demonstrated different rotational biomechanical characteristics than a group of healthy volunteers, and determine whether knee rotational biomechanical characteristics differ between male and female non-injured limbs in groups of both healthy volunteers and patients with a previous contralateral ACL injury. Fourteen healthy volunteers and 79 patients with previous unilateral ACL injury participated in this study. Patients were tested using a computerized tibial axial rotation system. Only the normal (non-operated) knee data were used for analysis. In order to assess the reliability of the robotic measurement system, 10 healthy volunteers were tested daily over four consecutive days by four different examiners. Rotational laxity and compliance measures demonstrated excellent reliability (ICC = 0.97). Patients with a contralateral ACL injury demonstrated significantly increased tibial internal rotation (20.6° vs. 11.4°, P < 0.001) and reduced external rotation (16.7° vs. 26.6°, P < 0.001) compared to healthy volunteers. Females demonstrated significantly increased internal and external rotation, as well as significantly increased rotational compliance compared with males (P < 0.05). Computer-assisted measurement techniques may offer clinicians an accurate, reliable, non-invasive method to select the most appropriate preventative or surgical interventions for patients with increased knee rotational laxity.

Impaired plasma nonesterified fatty acid tolerance is an early defect in the natural history of type 2 diabetes.

CONTEXT: Abnormal plasma nonesterified fatty acid (NEFA) metabolism may play a role in the development of type 2 diabetes. OBJECTIVES: Our objectives were to demonstrate whether there is a defect in insulin-mediated suppression of plasma NEFA appearance (RaNEFA) and oxidation (OxNEFA) during enhanced intravascular triacylglycerol lipolysis early in the natural history of type 2 diabetes, and if so, to determine whether other mechanisms than reduced insulin-mediated suppression of intracellular lipolysis are involved. DESIGN: These are cross-sectional studies. SETTING: The studies were performed at an academic clinical research center. PARTICIPANTS: Nine healthy subjects with both parents with type 2 diabetes (FH+) and nine healthy subjects with no first-degree relatives with type 2 diabetes (FH-) with similar anthropometric features were included in the studies. INTERVENTIONS: Pancreatic clamps and iv infusion of stable isotopic tracers ([1,1,2,3,3-(2)H5]-glycerol and [U-(13)C]-palmitate or [1,2-(13)C]-acetate) were performed while intravascular triacylglycerol lipolysis was simultaneously clamped by iv infusion of heparin plus Intralipid at low (fasting) and high insulin levels. Oral nicotinic acid (NA) was used to inhibit intracellular lipolysis. MAIN OUTCOME MEASURES: RaNEFA and OxNEFA were determined. RESULTS: During heparin plus Intralipid infusion at high plasma insulin levels, and despite similar intravascular lipolytic rates, FH+ had higher RaNEFA and OxNEFA than FH- (RaNEFA: 17.4+/-6.3 vs. 9.2+/-4.2; OxNEFA: 4.5+/-1.8 vs. 2.3+/-1.5 micromol/kg lean body mass/min), independent of NA intake, gender, age, and body composition. In the presence of NA, insulin-mediated suppression of RaNEFA was still observed in FH-, but not in FH+. CONCLUSIONS: Increased RaNEFA and OxNEFA during intravascular lipolysis at high insulin levels occur early in the natural history of type 2 diabetes.

[Tibial valgus osteotomy]. / Ostéotomie tibiale de valgisation.

The tibial valgus osteotomy whatever its technique has a survival rate of about 85 % to 10 years, if we consider the reoperation as a criterion of failure, with a confidence index at 78%. The age, weight, sex and functional signs have no impact on the outcome. We have found no evidence in the preoperative radiographic assessment, neither the medial pinch, or varus epiphyseal neither varisant gap, which could be a failure and a reoperation before the tenth year. Good results were observed significantly when there is an over-valgus at least 3 degrees of global axis of the lower limb. This corresponds to a valgus epiphyseal by more than 2 degrees . The substantial reduction in the gap varisant that lowers the overall time varisant below 200 kg cm provides the same positive results. The outcome will depend directly on the accuracy of the calculation of the preoperative correction performed and the quality of surgical achievement. Because of the need for precision, navigation technique appears as reliable, simple which makes it also possible to monitor the front slope and tibial rotation induced. The osteosynthesis must be stable and rigid to avoid postoperative loss of correction.

Superpixel and multi-atlas based fusion entropic model for the segmentation of X-ray images.

X-ray image segmentation is an important and crucial step for three-dimensional (3D) bone reconstruction whose final goal remains to increase effectiveness of computer-aided diagnosis, surgery and treatment plannings. However, this segmentation task is rather challenging, particularly when dealing with complicated human structures in the lower limb such as the patella, talus and pelvis. In this work, we present a multi-atlas fusion framework for the automatic segmentation of these complex bone regions from a single X-ray view. The first originality of the proposed approach lies in the use of a (training) dataset of co-registered/pre-segmented X-ray images of these aforementioned bone regions (or multi-atlas) to estimate a collection of superpixels allowing us to take into account all the nonlinear and local variability of bone regions existing in the training dataset and also to simplify the superpixel map pruning process related to our strategy. The second originality is to introduce a novel label propagation step based on the entropy concept for refining the resulting segmentation map into the most likely internal regions to the final consensus segmentation. In this framework, a leave-one-out cross-validation process was performed on 31 manually segmented radiographic image dataset for each bone structure in order to rigorously evaluate the efficiency of the proposed method. The proposed method resulted in more accurate segmentations compared to the probabilistic patch-based label fusion model (PB) and the classical patch-based majority voting fusion scheme (MV) using different registration strategies. Comparison with manual (gold standard) segmentations revealed that the good classification accuracy of our unsupervised segmentation scheme is, respectively, 93.79% for the patella, 88.3% for the talus and 85.02% for the pelvis; a score that falls within the range of accuracy levels of manual segmentations (due to the intra inter/observer variability).

Tibio-femoral joint contact in healthy and osteoarthritic knees during quasi-static squat: A bi-planar X-ray analysis.

The aim of this study was to quantify the tibio-femoral contact point (CP) locations in healthy and osteoarthritic (OA) subjects during a weight-bearing squat using stand-alone biplanar X-ray images. Ten healthy and 9 severe OA subjects performed quasi-static squats. Bi-planar X-ray images were recorded at 0°, 15°, 30°, 45°, and 70° of knee flexion. A reconstruction/registration process was used to create 3D models of tibia, fibula, and femur from bi-planar X-rays and to measure their positions at each posture. A weighted centroid of proximity algorithm was used to calculate the tibio-femoral CP locations. The accuracy of the reconstruction/registration process in measuring the quasi-static kinematics and the contact parameters was evaluated in a validation study. The quasi-static kinematics data revealed that in OA knees, adduction angles were greater (p<0.01), and the femur was located more medially relative to the tibia (p<0.01). Similarly, the average CP locations on the medial and lateral tibial plateaus of the OA patients were shifted (6.5±0.7mm; p<0.01) and (9.6±3.1mm; p<0.01) medially compared to the healthy group. From 0° to 70° flexion, CPs moved 8.1±5.3mm and 8.9±5.3mm posteriorly on the medial and lateral plateaus of healthy knees; while in OA joints CPs moved 10.1±8.4mm and 3.6±2.8mm posteriorly. The average minimum tibio-femoral bone-to-bone distances of the OA joints were lower in both compartments (p<0.01). The CPs in the OA joints were located more medially and displayed a higher ratio of medial to lateral posterior translations compared to healthy joints.

Treating hyperlipidemia for the primary prevention of coronary disease. Are higher dosages of lovastatin cost-effective?

OBJECTIVE: To compare the average and marginal life-time cost-effectiveness of increasing dosages of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, such as lovastatin, for the primary prevention of coronary heart disease (CHD). METHODS: We estimated the lifelong costs and benefits of the modification of lipid levels achieved with lovastatin based on published studies and a validated CHD prevention computer model. Patients were middle-aged men and women without CHD, with mean total serum cholesterol levels of 6.67, 7.84, and 9.90 mmol/L (258, 303, and 383 mg/dL), and high-density lipoprotein cholesterol levels of 1.19 mmol/L (46 mg/dL), as described in clinical trials. We estimated the cost per year of life saved for dosages of lovastatin ranging from 20 to 80 mg/d that reduced the total cholesterol level between 17% and 34%, and increased high-density lipoprotein cholesterol level between 4% and 13%. RESULTS: After discounting benefits and costs by 5% annually, the average cost-effectiveness of lovastatin, 20 mg/d, ranged from $11,040 to $52,463 for men and women. The marginal cost-effectiveness of 40 mg/d vs 20 mg/d remained in this range ($25,711 to $60,778) only for persons with baseline total cholesterol levels of 7.84 mmol/L (303 mg/dL) or higher. However, the marginal cost-effectiveness of lovastatin, 80 mg/d vs 40 mg/d, was prohibitively expensive ($99,233 to $716,433 per year of life saved) for men and women, irrespective of the baseline total cholesterol level. CONCLUSIONS: Assuming that $50,000 per year of life saved is an acceptable cost-effectiveness ratio, treatment with lovastatin at a dosage of 20 mg/d is cost-effective for middle-aged men and women with baseline total cholesterol levels of 6.67 mmol/L (258 mg/dL) or higher. At current drug prices, treatment with 40 mg/d is also cost-effective for total cholesterol levels of 7.84 mmol/L (303 mg/dL) or higher. However, treatment with 80 mg/d is not cost-effective for primary prevention of CHD.

An economic model for determining the costs and consequences of using various treatment alternatives for the management of arthritis in Canada.

OBJECTIVE: To construct a decision analytical model to compare the costs and clinical consequences of treating patients with celecoxib or various nonsteroidal anti-inflammatory drug (NSAID)/gastrointestinal (GI) co-therapy regimens for the management of osteoarthritis and rheumatoid arthritis. The model quantified the number of patients expected to experience any GI complication commonly associated with NSAID therapy. DESIGN: Resource use for the treatment of each GI complication in the model was estimated after consulting Canadian experts. Standard unit costs from Ontario were applied to resources to calculate the cost of each complication. MAIN OUTCOME MEASURES AND RESULTS: The model revealed that the NSAID-alone regimen was associated with the lowest cost [$262 Canadian dollars ($Can) per patient per 6 months] followed by the celecoxib regimen ($Can273), diclofenac/misoprostol ($Can365), NSAID + histamine H2 receptor antagonist ($Can413), NSAID + misoprostol ($Can421), and NSAID + proton pump inhibitor ($Can731). A break-even analysis showed that up to 80% of the study cohort could be treated with celecoxib instead of the NSAID-alone regimen without increasing the health system's overall budget. Celecoxib was associated with the fewest GI-related deaths, hospitalised events; symptomatic ulcers, and cases of anaemia. The celecoxib regimen was also associated with the fewest cases of upper GI distress. Sensitivity analyses revealed that the model was most sensitive to the distribution of GI risk in the population and to the ingredient costs of the treatment alternatives. CONCLUSIONS: This model indicates that the use of celecoxib could lead to the avoidance of a significant number of NSAID-attributable GI adverse events, and the incremental cost of using celecoxib for arthritis patients > or = 65 years of age in place of current treatment alternatives would not impose an excessive incremental impact on a Canadian provincial healthcare budget.

Reactive and proactive aggression: predictions to physical violence in different contexts and moderating effects of parental monitoring and caregiving behavior.

This study aimed at (a) comparing the links of proactive and reactive aggression at 13 years of age to delinquency-related violence and dating violence at ages 16 and 17, and (b) examining the moderating effects of parental supervision, and mother's and father's warmth and caregiving behaviors on these links. Based on a sample of 525 Caucasian boys, the results showed that proactive aggression uniquely predicted delinquency-related violence, whereas reactive aggression uniquely predicted later dating violence. The relation between proactive aggression and delinquency-related violence, however, was moderated by parental supervision. The relation between reactive aggression and dating violence was moderated by mother's warmth and caregiving behavior. The implications of the findings for the theoretical and practical distinction between proactive and reactive aggression are discussed.

[Lack of conviction about vaccination in certain Quebec vaccinators]. / Manque de conviction face à la vaccination chez certains vaccinateurs québécois.

A questionnaire was mailed to all vaccinators in Quebec in 1998. The objective of this survey was to document vaccinators' attitudes, knowledge, and practices related to vaccination. Vaccinators generally believe in the security, efficacy and usefulness of vaccines given to young children. However, 41% of nurses do not fully agree with these opinions. More than 94% of pediatricians completely disagree that "certain practices (homeopathy, good eating habits and a healthy lifestyle) can eliminate the need for vaccination", compared with 85% of general practitioners and only 60% of nurses. Less than 25% of doctors recall children who are late in getting their immunizations; approximately 45% of vaccinators are in complete agreement with simultaneous injections of two vaccines; many circumstances are incorrectly seen as contra indications for vaccination. Public health authorities should target systematic interventions towards vaccinators to improve this situation and to increase nurses' conviction regarding the benefits of vaccination.

Proximate effects of a child sexual abuse prevention program in elementary school children.

OBJECTIVE: The effects of the sexual child abuse prevention program ESPACE were evaluated by means of a Solomon-type design with first and third grade children. ESPACE is an adaptation of the American Child Assault Prevention Program (CAP). Possible side effects of the program were also examined. METHOD: A total of 133 children (64 first-graders and 69 third-graders) participated in the study. Children completed a knowledge questionnaire and a video vignette measure designed to evaluate preventive skills towards abusive and potentially abusive situations. A follow-up measure (2 months) was administered to verify whether knowledge and skills were maintained. RESULTS: Results indicated that children participating in the prevention program showed greater preventive knowledge and skills relative to children not participating. Follow-up data showed that knowledge gains were maintained while the preventive skill gains may attenuate. However, while global skill scores decreased between post-test and follow-up, children still showed greater preventive skills at follow-up than before the program. In terms of unanticipated side effects, results revealed that almost half of the parents noted positive reactions following children's participation in the ESPACE program. Furthermore, the majority of parents did not identify negative reactions in their children following their participation in the workshop. CONCLUSION: The findings suggest that the Quebec adaptation of the CAP program was effective in training children in abuse prevention concepts and skills.

Fatal nicotine ingestion.

Nicotine is one of the most readily available and commonly abused drugs in modern society. However, serious or fatal overdoses of this agent are rare. We present a case of intentional fatal ingestion of nicotine alkaloid solution. This diagnosis may be elusive since nicotine is commonly qualitatively identified on urine toxicology screens, but is seldom quantified. Clinicians should be knowledgeable about the nature of this agent and its pathophysiologic presentations since recognition of the toxidrome is often necessary to make this diagnosis.

A study of the prevalence of sexual coercion in adolescent heterosexual dating relationships in a Quebec sample.

Very few studies which have addressed the issue of sexual violence in dating relationships have provided prevalence rates for coercion that is perpetrated and sustained for both sexes during adolescence, while adequately accounting for the totality of unwanted sexual experiences. The present study addresses these issues by examining the rates of perpetrated and sustained sexual coercion among 644 French-speaking adolescents between 15 and 19 years of age with heterosexual dating experience from Quebec (Canada). Chi-square analyses reveal that girls are more often the victims of coercion, while boys more frequently perpetrate it. However, some boys are victims of sexual coercion. The most frequently occurring unwanted sexual experiences are kissing, and petting or fondling. Verbal coercion, consisting of continual arguments and pressure, is the strategy most often used by those who perpetrate unwanted sexual experiences, and is the strategy most frequently reported by those who suffer it. More extreme forms of sexual violence are also reported, but at a lower rate. Such high rates of sexual coercion during adolescence, as observed in the present study within a culture which is increasingly open to issues regarding sexuality, argue strongly for the implementation of prevention and intervention programs within this age group.

[Female victimization in the context of dating violence in adolescence: development of an instrument (VIFFA)]. / Violence faite aux filles dans le contexte des fréquentations à l'adolescence: élaboration d'un instrument (VIFFA).

The aim is to report on the development and preliminary validation of an instrument, VIFFA (Violence faite aux Filles dans les Fréquentations à l'Adolescence), on female victimization in the context of dating violence in adolescence. Objectives are twofold: to document the psychometric qualities of this self-report and to propose an instrument adapted to the context of young teens. The instrument refers to concepts of physical, emotional, and sexual abuse. Questioning in two phases is used to achieve proper understanding of the concept studied and to help select the partner to whom they refer in the second detailed phase. Girls were questioned on violence sustained and boys on violence inflicted. The total sample included 331 boys and 377 girls; their mean age was 14.6 years. A social desirability questionnaire was used to evaluate discriminant validity and the results indicate that the adolescents' answers were not distorted by social desirability. The factorial analyses resulted in 4 slightly different factors for girls and boys. With regard to the girls (violence sustained), the factors included Verbal and Emotional Abuse, Physical Abuse, Control through Jealousy and Sexual Abuse. With the boys (violence inflicted), the factors were Psychological Abuse, Jealousy and Sexual Abuse, Severe Physical Abuse and Minor Physical Abuse. Validation studies indicate that the instrument has adequate psychometric qualities and is adapted to the context of adolescence. An innovative aspect is the place given to items concerning jealousy.

[Contribution of individual characteristics to learning by children with first exposure to a prevention of abuse program]. / La contribution des caractéristiques individuelles aux apprentissages des enfants du primaire participant à un atelier de prévention des abus.

This study explores the contribution of personal characteristics in the knowledge and skills gains of children taking part in the child abuse prevention program ESPACE. The program is an adaptation of the widely implemented American Child Assault Prevention Program (CAP). A group of 107 fourth-grade children completed a knowledge questionnaire and a video vignette measure designed to evaluate preventive skills in abusive and potentially abusive situations. Children were also invited to complete questionnaires evaluating individual characteristics such as self-esteem, locus of control and self-efficacy. The results highlight the importance of certain individual variables such as the child's gender, self-efficacy and perception of athletic competence in the acquisition of sexual abuse preventive skills.

{Social support and the help offered by mothers to their psychologically troubled sons or daughters}. / L&apaide que des femmes offrent à leur fils ou à leur fille présentant des troubles psychotiques et le rseau de soutien de ces femmes.

We describe in this paper the everyday support mothers give to their adult sons or daughters suffering from psychotic disorders. We also describe the support these women receive from their social network regarding specific needs related to their children's disorders. Ninety-nine women, representing all socioeconomic groups, were interviewed. They were recruited through hospitals and self-help groups. The results of this study highlight the fact that participants give a substantial amount of support to their children, that they have considerable concern for their children's well-being, and that members of their family are their main source of emotional and practical support, and of advice. Mental health professionals give primarily informational support to respondents, in part through community-based agencies. The respondents who belong to self-help groups have significantly more needs related to their children's disorders and have more concern for their children's well-being than do the other respondents.

[Widowhood : problem and factors of adaptation.]. / Le veuvage : problèmes et facteurs d'adaptation.

The death of a spouse is a crisis situation which the majority of the population will experience. Some are affected over a long period by the effects of mourning, while others adapt more easily. Starting with a review of writing on the subject, this article describes first the principal stages of the mourning reaction, then it identifies the associated financial, health, and interpersonal problems experienced by widows and widowers. Age, income, previous mourning, the existence of a confidant, frequenting friends and other widows or widowers, satisfaction in relation to help received, participation in diverse associations, are the principal factors favouring adaptation to widowhood. Depressive behaviour, one month after onset of widowhood, and the delayed reaction to mourning indicate a possible negative reaction.