The forgotten joint score-12 is a valid and responsive outcome tool for measuring success following hip arthroscopy for femoroacetabular impingement syndrome.

PURPOSE: The forgotten joint score-12 (FJS-12) is an outcome questionnaire designed to evaluate joint awareness. The responsiveness and validity of the English language version of the FJS-12 in patients undergoing hip arthroscopy for femoroacetabular impingement (FAI) is not known. METHODS: Consecutive patients undergoing hip arthroscopy for a diagnosis of FAI were prospectively followed up over a 1 year period. Patients completed preoperative and postoperative FJS-12, EuroQol 5 Dimension (EQ-5D-5L), and the 12-item international hip outcome tool (iHOT-12). We evaluated construct validity with Spearman correlation coefficients for the FJS-12, and responsiveness by way of effect size and ceiling effects. RESULTS: Forty-six patients underwent hip arthroscopy, of which 42 (91%) completed post-operative PROMs at 1 year follow-up. Construct validity was strong with the iHOT-12 (r = 0.87) and also the EQ-5D-5L (r = 0.83). The median postoperative FJS score was 50.2 (IQR 64). The mean change in score for the FJS-12 was 31 points (SD 31) (p < 0.001), with an effect size (Cohen's d) of 1.16. Preoperatively, three patients scored the lowest possible value resulting in a floor effect of 7.1%. Similarly, only three patients (7.1%) scored the best possible score post-operatively. CONCLUSION: This is the first evaluation of the joint awareness concept in the English language version of the FJS-12 following hip arthroscopy for FAI. The FJS-12 is a valid and responsive tool for the assessment of this cohort of patients. LEVEL OF EVIDENCE: II.

Yellow Fever Outbreak - Kongo Central Province, Democratic Republic of the Congo, August 2016.

On April 23, 2016, the Democratic Republic of the Congo's (DRC's) Ministry of Health declared a yellow fever outbreak. As of May 24, 2016, approximately 90% of suspected yellow fever cases (n = 459) and deaths (45) were reported in a single province, Kongo Central Province, that borders Angola, where a large yellow fever outbreak had begun in December 2015. Two yellow fever mass vaccination campaigns were conducted in Kongo Central Province during May 25-June 7, 2016 and August 17-28, 2016. In June 2016, the DRC Ministry of Health requested assistance from CDC to control the outbreak. As of August 18, 2016, a total of 410 suspected yellow fever cases and 42 deaths were reported in Kongo Central Province. Thirty seven of the 393 specimens tested in the laboratory were confirmed as positive for yellow fever virus (local outbreak threshold is one laboratory-confirmed case of yellow fever). Although not well-documented for this outbreak, malaria, viral hepatitis, and typhoid fever are common differential diagnoses among suspected yellow fever cases in this region. Other possible diagnoses include Zika, West Nile, or dengue viruses; however, no laboratory-confirmed cases of these viruses were reported. Thirty five of the 37 cases of yellow fever were imported from Angola. Two-thirds of confirmed cases occurred in persons who crossed the DRC-Angola border at one market city on the DRC side, where ≤40,000 travelers cross the border each week on market day. Strategies to improve coordination between health surveillance and cross-border trade activities at land borders and to enhance laboratory and case-based surveillance and health border screening capacity are needed to prevent and control future yellow fever outbreaks.

A Genetic Epidemiological Mega Analysis of Smoking Initiation in Adolescents.

INTRODUCTION: Previous studies in adolescents were not adequately powered to accurately disentangle genetic and environmental influences on smoking initiation (SI) across adolescence. METHODS: Mega-analysis of pooled genetically informative data on SI was performed, with structural equation modeling, to test equality of prevalence and correlations across cultural backgrounds, and to estimate the significance and effect size of genetic and environmental effects according to the classical twin study, in adolescent male and female twins from same-sex and opposite-sex twin pairs (N = 19 313 pairs) between ages 10 and 19, with 76 358 longitudinal assessments between 1983 and 2007, from 11 population-based twin samples from the United States, Europe, and Australia. RESULTS: Although prevalences differed between samples, twin correlations did not, suggesting similar etiology of SI across developed countries. The estimate of additive genetic contributions to liability of SI increased from approximately 15% to 45% from ages 13 to 19. Correspondingly, shared environmental factors accounted for a substantial proportion of variance in liability to SI at age 13 (70%) and gradually less by age 19 (40%). CONCLUSIONS: Both additive genetic and shared environmental factors significantly contribute to variance in SI throughout adolescence. The present study, the largest genetic epidemiological study on SI to date, found consistent results across 11 studies for the etiology of SI. Environmental factors, especially those shared by siblings in a family, primarily influence SI variance in early adolescence, while an increasing role of genetic factors is seen at later ages, which has important implications for prevention strategies. IMPLICATIONS: This is the first study to find evidence of genetic factors in liability to SI at ages as young as 12. It also shows the strongest evidence to date for decay of effects of the shared environment from early adolescence to young adulthood. We found remarkable consistency of twin correlations across studies reflecting similar etiology of liability to initiate smoking across different cultures and time periods. Thus familial factors strongly contribute to individual differences in who starts to smoke with a gradual increase in the impact of genetic factors and a corresponding decrease in that of the shared environment.

Golfers are physically more active and have greater health associated quality of life than non-golfers following lower limb arthroplasty.

Background: The health benefits of physical activity are well recognised. This study assessed whether golfers were more physically active after lower limb arthroplasty when compared to those that did not play golf (primary outcome). In addition pre and postoperative changes in health-associated quality of life (HAQoL) and joint specific outcomes between golfers and none golfers were assessed (secondary outcomes). Methods: There were 304 patients [THA (n = 155) or TKA (n = 149)] prospectively registered during a 4-month period undergoing lower limb arthroplasty. The mean age was 70.0 (range 37-92, standard deviation 10.2) years and included 188 (61%) females and 120 (39%) males. They completed pre and postoperative questionnaires assessing recreational activity, physical activity, HAQoL (EuroQol [EQ]), joint specific health (Oxford scores), and satisfaction. Results: Golfers (n = 33, 10.9%) were more likely to achieve longer than 3 hours of moderate activity during a week (48.5% vs 38.0%, odds ratio (OR) 3.4, p = 0.045) and achieved their recommended activity level (96.8% vs 77.7%, OR 8.6, p = 0.015) compared to non-golfers following arthroplasty. Postoperative EQ5D (p = 0.034) and EQVAS (p = 0.019) were significantly greater in golfers. The joint specific Oxford hip score was greater in golfers compared to non-golfers (mean difference 5.6, p = 0.022), however no difference was observed in the Oxford knee score following TKA (p = 0.495). Conclusion: Golfers were more likely to achieve their weekly recommended level of physical activity and had a greater HAQoL relative to those that did not play golf following lower limb arthroplasty. More specifically after THA golfers also had a greater postoperative joint specific outcome, but no such advantage was observed in those following TKA. Evidence Level: Level II, diagnostic study.

Poly(allylamine)-tripolyphosphate polymeric nanoparticle as an NLRP3-dependent systemic adjuvant for the vaccine development.

Nanotechnology plays a crucial role in vaccine development and provides the opportunity to design functional nanoparticles (Np) of different compositions, sizes, charges and surface properties for biomedical applications. The present study aims to evaluate a complex coacervate-like Np composed of poly(allylamine hydrochloride) (PAH) and tripolyphosphate (Tpp) as a safe vehicle and adjuvant for systemic vaccines. We investigated the activation of different antigen-presenting cells (APCs) with Np-PAH and its adjuvanticity in Balbc/c and different KO mice that were intraperitoneally immunized with Np-OVA. We found that Np-PAH increased the expression of CD86 and MHCII and promoted the production and secretion of interleukin-1ß (IL-1ß) and IL-18 through the inflammasome NLRP3 when macrophages and dendritic cells were co-incubated with LPS and Np-PAH. We evidenced an unconventional IL-1ß release through the autophagosome pathway. The inhibition of autophagy with 3-methyladenine reduced the LPS/Np-PAH-induced IL-1ß secretion. Additionally, our findings showed that the systemic administration of mice with Np-OVA triggered a significant induction of serum OVA-specific IgG and IgG2a, an increased secretion of IFN-γ by spleen cells, and high frequencies of LT CD4 + IFN-γ + and LT CD8 + IFN-γ + . In conclusion, our findings show that PAH-based Np promoted the inflammasome activation of innate cells with Th1-dependent adjuvant properties, making them valuable for formulating of novel preventive or therapeutic vaccines for infectious and non-infectious diseases.

Functional fitness and physical activity of Portuguese community-residing older adults.

The purposes of this study were to generate functional-fitness norms for Portuguese older adults, to determine age and sex differences, and to analyze the physical activity-associated variation in functional fitness. The sample was composed of 802 older adults, 401 men and 401 women, age 60-79 yr. Functional fitness was assessed using the Senior Fitness Test. Physical activity level was estimated via the Baecke questionnaire. The P50 values decreased from 60 to 64 to 75 to 79 yr of age. A significant main effect for age group was found in all functional-fitness tests. Men scored significantly better than women in the chair stand, 8-ft up-and-go, and 6-min walk. Women scored significantly better than men in chair sit-and-reach and back scratch. Active participants scored better in functional-fitness tests than their average and nonactive peers. This study showed a decline in functional fitness with age, better performance of men, and increased proficiency in active participants.

Cost-utility analysis of total knee arthroplasty using 10-year data from a randomised controlled trial: Implant design influences quality-adjusted life year gain.

BACKGROUND: The aim of this study was to perform a cost-utility analysis for total knee arthroplasty (TKA) over a 10-year follow up period. METHODS: Two-hundred and twelve patients were randomised to receive either a Kinemax or a Triathlon TKA. Patients were assessed pre-operatively, and at 6 months, and 1, 3, 7 and 10 years postoperatively. The costs of the primary and revision surgery were accounted for. One-year quality-adjusted life year (QALY) gain was used to estimate 10-year gains using the established annual health gain discounts. RESULTS: Forty-eight patients died and eight were revised during the follow up period. Overall QALY gain per patient over the 10-year period was 2.594 and the cost per patient was £6559, which resulted in a cost per QALY of £2761 at 10 years. The Triathlon group had a significantly greater QALY gain compared with the Kinemax (mean difference (MD) 0.53, 95% CI 0.03-1.03, P = 0.02), which resulted in a cost per QALY for the Triathlon group of £2521 compared with £3107 for the Kinemax group at 10 years. The 5% annual discount resulted in a significantly lower QALY gain (MD 0.135, 95% CI 0.201-0.354, P = 0.002), whereas the 3.5% annual discount resulted in non-significant difference in QALY gain compared with the actual gain (MD 0.021, 95% CI -0.084 to 0.077, P = 0.292). CONCLUSIONS: TKA was a cost-effective intervention, and the Triathlon was associated with a greater cost effectiveness at 10 years. The 3.5% annual discounts for QALY gain would seem to be the most accurate, with an underestimation being observed with the 5% discount.

Female anthropometric variability and their effects on predicted thermoregulatory responses to work in the heat.

The use of thermoregulatory models for assessing physiological responses of workers in thermally stressful situations has been increasing because of the risks and costs related to human studies. In a previous study (Yokota et al. Eur J Appl Physiol 104:297-302, 2008), the effects of anthropometric variability on predicted physiological responses to heat stress in U.S. Army male soldiers were evaluated. Five somatotypes were identified in U.S. Army male multivariate anthropometric distribution. The simulated heat responses, using a thermoregulatory model, were different between somatotypes. The present study further extends this line of research to female soldiers. Anthropometric somatotypes were identified using multivariate analysis [height, weight, percent body fat (%BF)] and the predicted physiological responses to simulated exercise and heat stress using a thermoregulatory model were evaluated. The simulated conditions included walking at ~3 mph (4.8 km/h) for 300 min and wearing battle dress uniform and body armor in a 30°C, 25% relative humidity (RH) environment without solar radiation. Five major somatotypes (tall-fat, tall-lean, average, short-lean, and short-fat), identified through multivariate analysis of anthropometric distributions, showed different tolerance levels to simulated heat stress: lean women were predicted to maintain their core temperatures (T(c)) lower than short-fat or tall-fat women. The measured T(c) of female subjects obtained from two heat studies (data1: 30°C, 32% RH, protective garments, ~225 w·m(-2) walk for 90 min; data2: 32°C, 75% RH, hot weather battle dress uniform, ~378 ± 32 w·m(-2) for 30 min walk/30 min rest cycles for 120 min) were utilized for validation. Validation results agreed with the findings in this study: fat subjects tended to have higher core temperatures than medium individuals (data2) and lean subjects maintained lower core temperatures than medium subjects (data1).

Interrelationships among invasive and non-invasive indicators of biological maturation in adolescent male soccer players.

The relationships among indicators of biological maturation were evaluated and concordance between classifications of maturity status in two age groups of youth soccer players examined (11-12 years, n = 87; 13-14 years, n = 93). Data included chronological age (CA), skeletal age (SA, Fels method), stage of pubic hair, predicted age at peak height velocity, and percent of predicted adult height. Players were classified as on time, late or early in maturation using the SA-CA difference, predicted age at peak height velocity, and percent of predicted mature height. Factor analyses indicated two factors in players aged 11-12 years (maturity status: percent of predicted mature height, stage of pubic hair, 59% of variance; maturity timing: SA/CA ratio, predicted age at peak height velocity, 26% of variance), and one factor in players aged 13-14 years (68% of variance). Kappa coefficients were low (0.02-0.23) and indicated poor agreement between maturity classifications. Spearman rank-order correlations between categories were low to moderate (0.16-0.50). Although the indicators were related, concordance of maturity classifications between skeletal age and predicted age at peak height velocity and percent predicted mature height was poor. Talent development programmes call for the classification of youth as early, average, and late maturing for the purpose of designing training and competition programmes. Non-invasive indicators of maturity status have limitations for this purpose.

A Cost-Utility Analysis of Robotic Arm-Assisted Total Hip Arthroplasty: Using Robotic Data from the Private Sector and Manual Data from the National Health Service.

Purpose: The aim was to assess the cost-effectiveness of robotic arm-assisted total hip arthroplasty (rTHA) compared with manual total hip arthroplasty (mTHA) and to assess the influence of annual volume on the relative cost-effectiveness of rTHA. Methods: A database of both rTHA (n = 48 performed in a private centre) and mTHA (n = 512 performed in the National Health Service) was used. Patient demographics, preoperative Oxford hip score, forgotten joint score, EuroQol 5-dimensional 3-level (EQ-5D), and postoperative EQ-5D were recorded. Two models for incremental cost-effectiveness ratios using cost per quality-adjusted life year (QALY) for rTHA were calculated based on a unit performing 100 rTHAs per year: 10-year follow-up and a lifetime time horizon (remaining life expectancy of a 69-year-old patient). Results: When adjusting for confounding factors, rTHA was independently associated with a 0.091 (p=0.029) greater improvement in the EQ-5D compared to mTHA. This resulted in a 10-year time horizon cost per QALY for rTHA of £1,910 relative to mTHA, which increased to £2,349 per QALY when discounted (5%/year). When using the 10-year time horizon cost per QALY was approximately £3,000 for a centre undertaking 50 rTHAs per year and decreased to £1,000 for centre undertaking 200 rTHAs per year. Using a lifetime horizon, the incremental unadjusted cost per QALY gained was £980 and £1432 when discounted (5%/year) for rTHA compared with mTHA. Conclusions: Despite the increased cost associated with rTHA, it was a cost-effective intervention relative to mTHA due to the associated greater health-related quality of health gain, according to the EQ-5D outcome measure.

Prediction of adult height in girls: the Beunen-Malina-Freitas method.

The purpose of this study was to validate and cross-validate the Beunen-Malina-Freitas method for non-invasive prediction of adult height in girls. A sample of 420 girls aged 10-15 years from the Madeira Growth Study were measured at yearly intervals and then 8 years later. Anthropometric dimensions (lengths, breadths, circumferences, and skinfolds) were measured; skeletal age was assessed using the Tanner-Whitehouse 3 method and menarcheal status (present or absent) was recorded. Adult height was measured and predicted using stepwise, forward, and maximum R (2) regression techniques. Multiple correlations, mean differences, standard errors of prediction, and error boundaries were calculated. A sample of the Leuven Longitudinal Twin Study was used to cross-validate the regressions. Age-specific coefficients of determination (R (2)) between predicted and measured adult height varied between 0.57 and 0.96, while standard errors of prediction varied between 1.1 and 3.9 cm. The cross-validation confirmed the validity of the Beunen-Malina-Freitas method in girls aged 12-15 years, but at lower ages the cross-validation was less consistent. We conclude that the Beunen-Malina-Freitas method is valid for the prediction of adult height in girls aged 12-15 years. It is applicable to European populations or populations of European ancestry.

Preoperative morbidity and joint awareness while awaiting hip arthroscopy for femoroacetabular impingement.

PURPOSE: The Forgotten Joint Score (FJS-12) is a valid tool in the evaluation of patients undergoing hip arthroscopy, assessing the unique concept of joint awareness in the setting of a patient's hip pathology. The preoperative burden on patients' mental wellbeing of impaired joint function or symptoms is well established. The purpose of this study was to determine patients' awareness of their hip joint whilst awaiting hip arthroscopy for femoroacetabular impingement, to explore any association between joint awareness and mental health status, and to determine whether this relates to time spent waiting for arthroscopy preoperatively. METHODS: A prospective database of patients undergoing hip arthroscopy between January 2018 and November 2020 was analysed. All patients with a diagnosis of femoroacetabular impingement (FAI) undergoing arthroscopic treatment were included. Questionnaires included the FJS-12, twelve item international hip outcome tool (iHOT-12), EuroQol 5D-5L (EQ-5D-5L) and the Tegner activity score. Pearson's correlation coefficient was used to assess relationships between continuous variables. RESULTS: Preoperative functional outcomes were completed by 81 patients (97.5%) prior to undergoing hip arthroscopy. Median preoperative FJS-12 score was 16.67 (IQR 8.33 - 29.68). Forty-four patients reported any level of anxiety/depression preoperatively (54.3%). Preoperative FJS-12 showed a significant negative correlation with worsening mental health status (r = - 0.359, p <  0.001), and a significant positive correlation with EQ-5D-5L (r = 0.445, p <  0.001). The duration of symptoms or time on the waiting list did not correlate with increased joint awareness or worsened mental health. CONCLUSION: Joint awareness is high when awaiting hip arthroscopy for FAI. Increasing levels of joint awareness correlate with poorer mental health status and poorer quality of life measures, however these parameters do not seem to be associated with increased duration of symptoms prior to surgery or time on the waiting list for surgery.

Mucosal Immunoregulatory Properties of Tsukamurella inchonensis to Reverse Experimental Food Allergy.

The intestinal mucosa is lined by epithelial cells, which are key cells to sustain gut homeostasis. Food allergy is an immune-mediated adverse reaction to food, likely due to defective regulatory circuits. Tsukamurella inchonensis is a non-pathogenic bacterium with immunomodulatory properties. We hypothesize that the anti-inflammatory effect of dead T. inchonensis on activated epithelial cells modulates milk allergy through the restoration of tolerance in a mouse model. Epithelial cells (Caco-2 and enterocytes from mouse gut) and macrophages were stimulated with T. inchonensis and induction of luciferase under the NF-κB promoter, ROS and cytokines production were studied. Balb/c mice were mucosally sensitized with cow´s milk proteins plus cholera toxin and orally challenged with the allergen to evidence hypersensitivity symptoms. After that, mice were orally administered with heat-killed T. inchonensis as treatment and then challenged with the allergen. The therapeutic efficacy was in vivo (clinical score and cutaneous test) and in vitro (serum specific antibodies and cytokines-ELISA, and cell analysis-flow cytometry) evaluated. Heat-killed T. inchonensis modulated the induction of pro-inflammatory chemokines, with an increase in anti-inflammatory cytokines by intestinal epithelial cells and by macrophages with decreased OX40L expression. In vivo, oral administration of T. inchonensis increased the frequency of lamina propria CD4+CD25+FoxP3+ T cells, and clinical signs were lower in T. inchonensis-treated mice compared with milk-sensitized animals. In vivo depletion of Tregs (anti-CD25) abrogated T. inchonensis immunomodulation. In conclusion, these bacteria suppressed the intestinal inflammatory immune response to reverse food allergy.

Cross-validation of the Beunen-Malina method to predict adult height.

The purpose of this study was to cross-validate the Beunen-Malina method for non-invasive prediction of adult height. Three hundred and eight boys aged 13, 14, 15 and 16 years from the Madeira Growth Study were observed at annual intervals in 1996, 1997 and 1998 and re-measured 7-8 years later. Height, sitting height and the triceps and subscapular skinfolds were measured; skeletal age was assessed using the Tanner-Whitehouse 2 method. Adult height was measured and predicted using the Beunen-Malina method. Maturity groups were classified using relative skeletal age (skeletal age minus chronological age). Pearson correlations, mean differences and standard errors of estimate (SEE) were calculated. Age-specific correlations between predicted and measured adult height vary between 0.70 and 0.85, while age-specific SEE varies between 3.3 and 4.7 cm. The correlations and SEE are similar to those obtained in the development of the original Beunen-Malina method. The Beunen-Malina method is a valid method to predict adult height in adolescent boys and can be used in European populations or populations from European ancestry. Percentage of predicted adult height is a non-invasive valid method to assess biological maturity.

Prevalence of overweight, obesity and physical activity levels in children from Azores Islands.

BACKGROUND: Childhood overweight and obesity are increasing all over the world and have been associated with low levels of physical activity (PA). AIMS: To determine the prevalence of overweight, obesity and PA levels in Azorean children according to age and sex; and to determine the association between levels of PA and prevalence of overweight and obesity. SUBJECTS AND METHODS: Weight, height and PA levels were measured in 3699 children aged 6-10 years, from the Azores Islands, Portugal. Overweight and obesity were classified according to the cut-offs of Cole et al. (BMJ 320:1240-1243, 2000) . RESULTS: In girls, prevalences of overweight and obesity were 22.8% and 13.2%, and in boys 17.6% and 12.3%, respectively. No age trends were found in the prevalence of overweight or obesity; however, girls had a higher risk of being overweight (OR = 1.4, 95% CI = 1.2-1.7) than boys. Levels of PA were higher in boys compared to girls (F(1) = 52.8, p < 0.001). A protective effect of PA practice (very active versus less active) was observed for obesity (OR = 0.7; 95% CI = 0.5-0.9). CONCLUSION: The results demonstrate the existence of high prevalence of overweight and obesity in children from the Azores Islands, which is associated with low levels of PA.

Disordered eating and weight changes after deployment: longitudinal assessment of a large US military cohort.

The effect of military deployments to combat environments on disordered eating and weight changes is unknown. Using longitudinal data from Millennium Cohort Study participants who completed baseline (2001-2003) and follow-up (2004-2006) questionnaires (n=48,378), the authors investigated new-onset disordered eating and weight changes in a large military cohort. Multivariable logistic regression was used to compare these outcomes among those who deployed and reported combat exposures, those who deployed but did not report combat exposures, and those who did not deploy in support of the wars in Iraq and Afghanistan. Deployment was not significantly associated with new-onset disordered eating in women or men, after adjustment for baseline demographic, military, and behavioral characteristics. However, in subgroup comparison analyses of deployers, deployed women reporting combat exposures were 1.78 times more likely to report new-onset disordered eating (95% confidence interval: 1.02, 3.11) and 2.35 times more likely to lose 10% or more of their body weight compared with women who deployed but did not report combat exposures (95% confidence interval: 1.17, 4.70). Despite no significant overall association between deployment and disordered eating and weight changes, deployed women reporting combat exposures represent a subgroup at higher risk for developing eating problems and weight loss.

Military services fitness database: development of a computerized physical fitness and weight management database for the U.S. Army.

The Department of Defense (DoD) has mandated development of a system to collect and manage data on the weight, percent body fat (%BF), and fitness of all military personnel. This project aimed to (1) develop a computerized weight and fitness database to track individuals and Army units over time allowing cross-sectional and longitudinal evaluations and (2) test the computerized system for feasibility and integrity of data collection over several years of usage. The computer application, the Military Services Fitness Database (MSFD), was designed for (1) storage and tracking of data related to height, weight, %BF for the Army Weight Control Program (AWCP) and Army Physical Fitness Test (APFT) scores and (2) generation of reports using these data. A 2.5-year pilot test of the MSFD indicated that it monitors population and individual trends of changing body weight, %BF, and fitness in a military population.

Fracture of a BIOLOX Delta Ceramic Femoral Head: A Case Report and Update of the Literature.

CASE: A 52-year-old man underwent right total hip replacement with a 32-mm BIOLOX delta ceramic head with a polyethylene liner. At 8 months, he fell onto his right hip. Radiographs at the time were unremarkable. One month later, he noticed a sharp pain and a sensation of grinding in his right hip; radiographs of the hip showed a fracture of the ceramic head. CONCLUSIONS: This case further demonstrates that fourth-generation ceramic heads can fracture, and delays in catastrophic failure of ceramics in total hip arthroplasty (THA) following trauma may be secondary to the "slow crack growth" hypothesis.

Genome-wide linkage scan for contraction velocity characteristics of knee musculature in the Leuven Genes for Muscular Strength Study.

The torque-velocity relationship is known to be affected by ageing, decreasing its protective role in the prevention of falls. Interindividual variability in this torque-velocity relationship is partly determined by genetic factors (h(2): 44-67%). As a first attempt, this genome-wide linkage study aimed to identify chromosomal regions linked to the torque-velocity relationship of the knee flexors and extensors. A selection of 283 informative male siblings (17-36 yr), belonging to 105 families, was used to conduct a genome-wide SNP-based (Illumina Linkage IVb panel) multipoint linkage analysis for the torque-velocity relationship of the knee flexors and extensors. The strongest evidence for linkage was found at 15q23 for the torque-velocity slope of the knee extensors (TVSE). Other interesting linkage regions with LOD scores >2 were found at 7p12.3 [logarithm of the odds ratio (LOD) = 2.03, P = 0.0011] for the torque-velocity ratio of the knee flexors (TVRF), at 2q14.3 (LOD = 2.25, P = 0.0006) for TVSE, and at 4p14 and 18q23 for the torque-velocity ratio of the knee extensors TVRE (LOD = 2.23 and 2.08; P = 0.0007 and 0.001, respectively). We conclude that many small contributing genes are involved in causing variation in the torque-velocity relationship of the knee flexor and extensor muscles. Several earlier reported candidate genes for muscle strength and muscle mass and new candidates are harbored within or in close vicinity of the linkage regions reported in the present study.