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.

Arthroscopic-assisted robotic bi-unicompartmental knee arthroplasty: a pilot cadaveric study

INTRODUCTION

Although bicondylar arthroplasty showed great functional results, it encounters some difficulties to be performed routinely. On the other hand, arthroscopic techniques tend to replace open surgical techniques in sports medicine but strive to be developed in the field of arthroplasty. This study aimed to assess the feasibility of a micro-invasive bi-compartmental knee arthroplasty using both arthroscopic and robotic technologies (A-BiUKA).

MATERIALS AND METHODS

The study was conducted on complete fresh-frozen and embalmed cadaveric specimens. The main criterion of judgment was the successful positioning of trial implants through a minimal quad-sparing approach. Arthroscopy was used for bone-morphing and burring, supported by an image-free robotic system. Secondary criteria of judgment were axial deviation (measured using the navigation system), operating time, and incision length.

RESULTS

Ten A-BiUKA were performed. Implantation was successful in all cases. The mean preoperative frontal deviation was 179.8° ± 3.2 [175: 185], the mean postoperative frontal deviation was 178.5° ± 2.2 [175: 182], without any outliers. The mean correction was 1.7° ± 1.6 [0: 5]. Once the eight first A-UKA were performed, constituting the learning curve, the mean operative time for the remaining twelves surgeries was 90 min ± 6. The mean skin incision length was 3.35 cm ± 0.13 [3: 4].

CONCLUSION

Associated arthroscopic and robotic technologies allows to perform Bi-UKA procedure using a quad sparing mini-invasive approach. Clinical prospective studies have to confirm the feasibility and the clinical outcomes of this surgery.

A method for quantitative evaluation of a valgus knee orthosis using biplane x-ray images

Knee orthoses are designed to reestablish the normal kinematics of the knee joint. However, the data on the effectiveness of them on modifying the internal joint kinematics are scarce. The aim of this study was to develop a method to allow accurate comparison of the knee contact kinematics in osteoarthritic (OA) subjects with and without wearing a valgus knee orthosis using imaging techniques. Biplane x-ray images of a subject (68 yrs., female, 1.70 m, 89 kg, left knee) was recorded during a weight-bearing squat at five positions. The same squat trial was repeated while wearing the orthosis. The 3D models of the knee were reconstructed from the biplane x-rays and the joint kinematics as well as the tibiofemoral contact point locations and bone-to-bone distance were compared at each posture. This could be seen as a proof of concept for the use of contact point locations as a parameter for evaluating the effectiveness of knee orthoses.Clinical Relevance- Joint kinematics derived from the skin markers suffer from low accuracy. The real impact of the knee orthoses on the skeleton takes vigorous techniques, which allows detecting the subtle kinematics changes directly at the joint level.

Can total knee arthroplasty restore the correlation between radiographic mechanical axis angle and dynamic coronal plane alignment during gait?

BACKGROUND

Total knee arthroplasty (TKA) is the treatment of choice for end-stage knee osteoarthritis. Postoperative static knee alignment has been recognized as a key component of successful surgery. A correction toward the kinematics of a native knee is expected after TKA, with an aim for neutral mechanical alignment. The evolution of frontal plane knee kinematics is not well understood.

METHODS

Nineteen patients awaiting TKA were recruited. Three-dimensional knee kinematics during treadmill gait were assessed pre-operatively, 12 months after surgery, and compared to a control group of 17 asymptomatic participants.

RESULTS

Mean radiographic mechanical alignment was corrected from 5.4° ± 5.0 (Standard Deviation) varus pre-operatively to 0.1° ± 2.0 (Standard Deviation) valgus postoperatively (P = 0.002). Mean stance coronal plane alignment decreased from 6.7° ± 4.0 (Standard Deviation) varus per-operatively to 2.1° ± 3.8 (Standard Deviation) postoperatively (P = 0.001). Correlation between radiographic mechanical axis angle and dynamic frontal plane alignment during gait, before and after surgery, was weak (pre-operative R = 0.41; postoperative R = 0.13) compared to control (R = 0.88). In the sagittal plane, TKA patients maintained their pre-operative stiff knee gait adaptation. Postoperative transverse plane kinematics suggested restoration of external tibial rotation during swing after TKA compared to control (Pre-operative 3.1°, postoperative 6.8°, control 7.1°, P = 0.05).

CONCLUSION

The lack of correlation between static and dynamic alignment suggests that static radiographic coronal alignment of the knee does not accurately predict dynamic behavior. In the sagittal plane, pre-operative gait adaptations were still present 12 months after surgery, supporting the need for a functional assessment to guide postoperative rehabilitation following TKA.

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).

The impact of bone morphology on the outcome of the pivot shift test: a cohort study

BACKGROUND

The presence of a positive pivot shift after surgical repair of the ACL is considered an important indicator of a failed reconstruction. The ability to predict the result of a pivot shift test after an ACL reconstruction using variables that can be measured prior to surgery could provide an indication of which patients may be at-risk of a poor surgical outcome.The purpose of this study was to determine whether structural characteristics of the femur and tibia, measured using plain radiographs, were associated with the result of the pivot shift test in unilateral ACL reconstructed patients.

METHODS

Sixteen patients who had undergone unilateral ACL reconstruction were divided into two groups based on the results of manual pivot shift testing: 1) Pivot group; and 2) No pivot group. All patients had standing true lateral radiographs of both knees. Structural measurements of the tibia and femur were made on both knees. In addition, two new variables were created to describe the tibiofemoral mismatch: 1) Femur Tibia Size Ratio (FTSR); and 2) Tibia to Posterior Femoral Condyle Ratio (TPFCR). These measures were compared within groups and between groups.

RESULTS

None of the individual structural characteristics were significantly different when compared between groups. No individual structural characteristics had a significant association with the presence of a positive pivot shift. When a between-group analysis was performed, both the FTSR (p < 0.03) and the TPFCR (p < 0.01) were significantly different between the Pivot group and the No Pivot group. A larger FTSR ratio, or a larger femur relative to the tibia, was associated with a positive pivot shift. A smaller TPFCR ratio, or a smaller tibial depth relative to the depth of the lateral posterior femoral condyle, was associated with a positive pivot shift.

CONCLUSIONS

Structural characteristics in the lateral femoral condyle and lateral tibial plateau were found to be associated with the presence of a positive pivot shift. These characteristics could separate between patients in the Pivot group and the No Pivot group. Two indices, the FTSR and the TPFCR, provided better predictive value than individual characteristics in identifying patients with a knee that was structurally "at-risk" for developing a positive pivot shift.

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.

Total knee replacement with retention of both cruciate ligaments

We report on the long-term results of 163 bicruciate-retaining Hermes 2C total knee replacements in 130 patients at a mean follow-up of 22.4 years (20.3 to 23.5). Even when the anterior cruciate ligament had a partially degenerative appearance it was preserved as long as the knee had a normal anterior drawer and Lachman’s test pre-operatively. The description and surgical technique of this minimally constrained prosthesis were published in 1983 and the ten-year clinical results in 1999.

A total of 12% of the knees (20 of 163) in this study were revised because of wear of the polyethylene tibial insert. Excellent stability was achieved and the incidence of aseptic component loosening was 4.3% (seven of 163). The survival rate using revision for any reason as the endpoint was 82% (95% confidence interval 76.2 to 88.0).

Although this series included a relatively small number of replacements, it demonstrated that the anterior cruciate ligament, even when partially degenerated at the time of TKR, remained functional and provided adequate stability at a long-term follow-up.

Cite this article: Bone Joint J 2013;95-B:917–22.

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.

Clinicians' opinions on new vaccination programs implementation

In Canada, several new vaccines were recently approved for clinical use or are expected to be soon. Decision-makers are faced with the choice whether or not to include these vaccines in publicly funded vaccination programs. The aim of this study was to assess Canadian pediatricians' and family physicians' opinions regarding 7 new vaccines, and perceived priority for the introduction of new programs. A self-administered, anonymous, mail-based questionnaire was sent during fall 2009 to a random sample of 1182 family physicians and to all 1852 Canadian pediatricians. Responses to 8 statements regarding frequency and severity of the diseases, efficacy and safety of the vaccines as well as feasibility of immunization programs were used to calculate priority scores to rank the 7 potential new vaccination programs (calculated scores ranging from 0 to 100). Overall response rate was 43%. The majority of respondents perceived the health and economic burden of diseases prevented by the seven new vaccines as important and considered new vaccines to be safe and effective. More than 90% of physicians strongly agreed or agreed that the new vaccines would be or are currently well accepted by the public and by the health professionals who administer vaccines, except for the HPV and rotavirus vaccines (respectively 30% and 29% strongly agreed or agreed). Mean priority scores were: 77.4 out of 100 for the measles, mumps, rubella and varicella (MMRV) combined vaccine; 75.6 for the hexavalent (DTaP-IPV-Hib-HBV) vaccine; 73.1 for the new pneumococcal conjugate vaccines; 69.8 for the meningococcal ACYW135; 68.9 for the combined hepatitis A and B; 63.5 for the human papillomavirus vaccine and 56.9 for the rotavirus vaccine. Health professionals' opinion is an important element to consider in the decision-making process regarding implementation of new immunization programs. Without health professional support, the introduction of a new vaccination program may be unsuccessful. In this study, the MMRV and the hexavalent (DTaP-IPV-Hib-HBV) vaccines received the highest ratings.

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.

Relationship between total and high molecular weight adiponectin levels and plasma nonesterified fatty acid tolerance during enhanced intravascular triacylglycerol lipolysis in men

CONTEXT

Increased plasma nonesterified fatty acid (NEFA) appearance during enhanced intravascular triacylglycerol (TG) lipolysis is a marker of metabolic adipose tissue dysfunction and may lead to the development of insulin resistance. The relationship between total and high molecular weight (HMW) adiponectin levels, NEFA appearance, and total TG lipolytic capacity has not been previously studied in humans.

OBJECTIVES

Our objective was to determine whether total and HMW adiponectin plasma levels are associated with plasma NEFA level and appearance, and with total TG lipolytic rate during enhanced intravascular TG lipolysis in men.

DESIGN

This was a cross-sectional metabolic study.

SETTING

The study was performed at an academic clinical research center.

PARTICIPANTS

There were 15 healthy men (mean +/- sd body mass index 25.5 +/- 4.7 kg/m(2)) aged 21-50 yr (mean +/- sd 31.1 +/- 10.2) without first-degree relatives with type 2 diabetes included in the study.

INTERVENTIONS

Pancreatic clamps and iv infusion of stable isotopic tracers ([1,1,2,3,3-(2)H(5)]glycerol and [U-(13)C]palmitate) were performed, whereas intravascular TG lipolysis was clamped by iv infusion of heparin plus Intralipid at low (fasting) and high insulin levels. Total and HMW adiponectin levels were measured using an ELISA.

MAIN OUTCOME MEASURES

Levels of total and HMW adiponectin, palmitate appearance (plasma palmitate appearance rate), and glycerol appearance (plasma glycerol appearance rate) were calculated.

RESULTS

During heparin plus Intralipid infusion, total and HMW adiponectin was inversely correlated with plasma palmitate appearance rate (r = -0.65; P = 0.01), but this association was lost when expressed per nonlean weight. Adiponectin levels were positively associated with plasma glycerol appearance rate per nonlean weight (r = 0.71 and r = 0.66, respectively; P < or = 0.01).

CONCLUSIONS

Increased adipose tissue mass likely explains the association between low adiponectin and reduced NEFA tolerance. Adiponectin level is a marker of total TG lipolytic rate per adipose tissue mass in men.

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.

Drug utilization review of celecoxib in Ontario

Cyclooxygenase (COX)-2-specific inhibitors were developed to circumvent the gastrointestinal toxicity of non-specific non-steroidal anti-inflammatory drugs while maintaining efficacy. However, the higher acquisition cost of COX-2-specific inhibitors has resulted in the implementation of a programme for cost containment in the Ontario public drug program. This programme consists of limited use (LU) criteria that need to be met for drug reimbursement of patients with osteoarthritis (OA) or rheumatoid arthritis (RA). Determining the proportion of patients eligible for reimbursement for celecoxib according to the LU criteria (based on prior treatment failure and the presence or history of serious ulcer-related gastrointestinal complications) can provide an indication of the extent of adherence to suggested guidelines. Using a patient-based survey and an analysis of the Ontario Drug Benefit Program database, the proportion of patients prescribed celecoxib who met rigorous or pragmatic definitions of the LU criteria was determined. The extent of coprescription of gastroprotective agents among patients taking celecoxib was also determined. Using the pragmatic definition, the majority of patients in the patient-based survey (53% for OA and 81% for RA) met the LU criteria. Similarly, in the database analysis, the majority of patients (76% for OA and 78% for RA) met the LU criteria. These data suggest that physician prescribing of celecoxib is consistent with the LU criteria. Concomitant prescription of gastroprotective agents in patients taking celecoxib was approximately 40%. It is recommended that further investigations be performed to determine the long-term impact of LU criteria on clinical and economic outcomes, since these criteria may also serve to restrict use in patients who may benefit from taking COX-2-specific inhibitors.

Persistency of use of COX-2-specific inhibitors and non-specific non-steroidal anti-inflammatory drugs (NSAIDs) in Quebec

The effectiveness of pharmacological therapies is dependent in part on patient persistency with the prescribed therapeutic regimen. In the case of non-specific non-steroidal anti-inflammatory drugs (NSAIDs), effectiveness is often compromised by undesirable side-effects, poor compliance or discontinuation of therapy. While patterns of utilization of non-specific NSAIDs have been investigated, few data are available on the patterns of persistency for cyclooxygenase (COX)-2-specific inhibitors. This study used a provincial health-care system database in Quebec, Canada, to determine the duration of treatment in new users of COX-2-specific inhibitors and non-specific NSAIDs over the first 3 months of treatment, and to characterize the factors associated with treatment persistency. Results demonstrate that the median duration of treatment was longer among patients initially prescribed COX-2-specific inhibitors (30 days and 23 days for celecoxib and rofecoxib respectively) than in those prescribed non-selective NSAIDs (10 days). Although the percentage of patients remaining on COX-2-specific drugs declined over the course of treatment, few patients on either celecoxib or rofecoxib switched drugs, either to the other COX-2-specific inhibitor or to non-specific NSAIDs. Factors associated with persistent drug use were: COX-2-specific inhibitors, age, and the use of gastroprotective agents either at treatment initiation or during follow-up. Dosage, chronic disease score and prescriber's specialty were only marginally associated with persistency. Prior use of gastroprotective agents was associated with lower persistency. Although the limitations of this study, which included lack of information on the indication for the prescription and the reason for switch or discontinuation, preclude definite conclusions regarding patterns of use of these drugs, the data suggest that the use of COX-2-specific inhibitors may result in increased persistency with treatment.

Cardiac procedure use and outcomes in elderly patients with acute myocardial infarction in the United States and Quebec, Canada, 1988 to 1994

BACKGROUND

Studies from the early 1990s have documented greater intensity of treatment for patients with acute myocardial infarction (AMI) in the United States compared with Canada, with little difference in health outcomes. Little is known about whether treatments and outcomes are changing differently over time in the two countries, and whether the differences vary with patient age.

METHODS

We conducted a retrospective cohort study of trends in cardiac procedure use, mortality, and recurrent AMI for patients 65 years or older hospitalized with AMI in the United States and Quebec. We examined Medicare claims and enrollment data from the United States (1.5 million) and provincial claims data from Quebec (35,000) between 1988 and 1994.

RESULTS

Use of cardiac procedures grew more rapidly between 1988 and 1994 in the United States, particularly for patients 75 years or older; unlike in Quebec, these cardiac procedures were performed soon after AMI. Both countries experienced significant declines in 1-year mortality: the decline averaged 1.27% points per year in the United States and 1.05% points in Quebec (P = ns). For AMI patients 75 years or older, 30-day and 1-year mortality declined approximately twice as rapidly in the United States as in Quebec (P < 0.01). The decline in mortality in the United States relative to Canada was significantly greater among patients 75 years or older but not among those age 65 to 74 years. Readmission rates with recurrent AMI were almost unchanged.

CONCLUSIONS

Over time, the use of cardiac procedures in elderly patients with AMI has risen more rapidly in the United States than in Quebec. These differences in procedure trends were associated with reductions in overall long-term AMI mortality in both countries.

[Female victimization in the context of dating violence in adolescence: development of an 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.

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]

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.

[Lack of conviction about vaccination in certain Quebec vaccinators]

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.

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.

Changes in the treatment and outcomes of acute myocardial infarction in Quebec, 1988-1995

BACKGROUND

Few studies have reported population-based information on the treatment trends and outcomes of patients who have had an acute myocardial infarction (AMI). We therefore examined patterns of care and outcomes for AMI patients in Quebec, Canada, between 1988 and 1995.

METHODS

Longitudinal data files of hospital admissions in Quebec (Med-Echo database) and inpatient and outpatient services (Régie de l'Assurance Maladie du Québec database) were used to construct cohorts of all AMI patients in the province between 1988 and 1995. Temporal trends in the use of cardiac procedures after an AMI, discharge prescriptions and mortality rates were examined.

RESULTS

Between 1988 and 1995 the age- and sex-adjusted rates of AMI in the Quebec population declined (148 per 100,000 in 1988 to 137 per 100,000 in 1995). The use of intensive cardiac procedures increased in the same period; the 1-year cumulative incidence rate of catheterization increased from 28% in 1988 to 31% in 1994, that of angioplasty rose from 8% to 15% and that of coronary artery bypass surgery from 6% to 8%. Prescriptions for ASA, beta-blockers, lipid-lowering agents and angiotensin-converting enzyme inhibitors increased, and prescriptions for nitrates and calcium antagonists decreased. These temporal changes were paralleled by a decrease in mortality rates post-AMI. All-cause 1-year cumulative incidence mortality rates decreased from 23% in 1988 to 19% in 1994.

INTERPRETATION

The decrease in AMI-related mortality in Quebec between 1988 and 1995 may be linked to changes in treatment strategies (i.e., increased use of cardiac surgical procedures and medications shown to increase survival).

[Contribution of individual characteristics to learning by children with first exposure to a prevention of abuse program]

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.

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.

The experience of caregiving among mothers of adults suffering from psychotic disorders: factors associated with their psychological distress

To identify correlates of psychological distress among multiple indicators, 99 women with adult children suffering from a psychotic disorder were interviewed. The women, who were recruited through hospitals and self-help groups, represented different socioeconomic levels. A face-to-face standardized interview was conducted, mainly in the participants' homes. Multiple hierarchical regression analysis showed that dimensions of burden and social support were strongly associated with distress reported by the participants. The negative interactions that participants had with their main confidant or spouse constituted a more powerful correlate than their perception of the quality of this relationship. Furthermore, a perception of their own health as poorer is a strong correlate of their distress. Since no control group was studied simultaneously, these results suggest, but do not prove, the presence of differences between mothers of adults with psychotic disorders and other mothers.

A head-to-head comparison of the cost effectiveness of HMG-CoA reductase inhibitors and fibrates in different types of primary hyperlipidemia

The objective of this study was to compare the lifetime cost-effectiveness of HMG-CoA reductase inhibitors and fibrates for the treatment of hyperlipidemia. Estimates of lipid modification achieved due to drug therapy were based on published head-to-head comparisons of specific HMG-CoA reductase inhibitors and fibrates in randomized, double-blind studies. We used a validated coronary heart disease (CHD) prevention computer model to estimate the costs and benefits of lifelong lipid modification. The patients were middle-aged men and women who were free of CHD, with either primary type IIa or IIb hyperlipidemia. The intervention used were specific HMG-CoA reductase inhibitors and fibrates at several dosages, which reduced total cholesterol 11-34% and increased high-density lipoprotein cholesterol 1-29%. The main outcome measure was the cost per year of life saved after discounting benefits and costs by 5% annually. The lifetime cost effectiveness of HMG-CoA reductase inhibitors (fluvastatin, lovastatin, pravastatin, simvastatin) and fibrates (bezafibrate, fenofibrate, gemfibrozil) for the treatment of primary hyperlipidemia varied according to patient population, the effectiveness of each drug in modifying lipid levels, and the price of each drug. The estimates of cost per year of life saved for HMG-CoA reductase inhibitors range from $19,886 to $73,632, and $16,955 to $59,488 for fibrates according to gender and type of primary hyperlipidemia. Fluvastatin 20 mg/day was significantly more cost effective than gemfibrozil 1200 mg/day for male patients with type IIa hyperlipidemia. Simvastatin 17.3 mg/day or 20 mg/day yielded similar cost-effectiveness ratios compared with fibrates among type II hyperlipidemic patients. However, micronized fenofibrate was more cost effective than simvastatin 20 mg/day among type IIb patients. The cost effectiveness of lipid therapy varies widely and can be maximized by selecting specific drugs for specific lipid abnormalities.

{Social support and the help offered by mothers to their psychologically troubled sons or daughters}

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.

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.

Homicide, schizophrenia and substance abuse or dependency

Few studies have extensively studied the aggressive behaviours of mentally disordered offenders. This investigation compared 14 schizophrenics found not guilty of homicide by reason of insanity (NGRI) with 12 schizophrenics convicted of homicide. A comparison group of 15 homicide offenders with no major mental disorder was used. Drug and alcohol consumption, previous history of aggression against others as well as mental health were assessed using standardized, reliable, valid instruments. Significantly more of the inmates with no major mental disorder were diagnosed as having a history of drug or alcohol abuse or dependency (60%) than the NGRI schizophrenics (35.7%). In addition, both groups of convicted homicide offenders were more likely to have committed homicide under the influence of drugs or alcohol than the NGRI group. No significant difference distinguished the groups for the mean number of aggressive incidents. The subjects found NGRI assaulted more often during an acute phase of mental illness than the convicted schizophrenics. Although both groups appeared to have a similar number of hospitalizations, most of the hospitalizations of the convicted schizophrenics occurred after the crime.

[Widowhood : problem and factors of 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.