A new 3D software for analysis and planning of lower limb and patellofemoral alignment: Reliability and accuracy

BACKGROUND

The new software, mediCAD® 3D Knee Sport (mediCAD Hectec GmbH, Altdorf/Landshut, Germany), promises to combine automated digital 3D bone model generation, 3D analysis of lower limb geometry including analysis of the patellofemoral joint, and osteotomy planning. The aim of this study was to evaluate its reliability and accuracy.

METHODS

In this retrospective multi-observer study, three post-mortem CTs were analysed by three observers at three points in time. Reliability was evaluated by calculating the intraclass correlation coefficient (ICC) of interobserver agreement. Accuracy was evaluated using the mean deviation D from the mean and the standard deviation SD from D.

RESULTS

Ten of 18 alignment parameters showed excellent, two good and three moderate interobserver agreement. Poor agreement was found for the mechanical medial proximal tibial angle, the trochlear sulcus angle and trochlea depth. Mean interobserver ICC of all parameters ranged from 0.32 to 0.99. Fifteen of 18 parameters showed a low mean deviation D from the mean of < 2 mm / 2°. Three parameters related to the patellofemoral joint showed medium or high D (patella tilt, trochlear sulcus angle, patellar ridge angle). These parameters also showed the highest values for the SD of D. The trochlear sulcus angle was found to be the only parameter with high mean deviation (D ≥ 5 mm/5°) with D being 5.67 ± 3.23°.

CONCLUSIONS

The current version of the software achieves good interobserver reliability and accuracy with the exception of a few measurement parameters.

Three-dimensional assessment of patellofemoral anatomy: Reliability and reference ranges

BACKGROUND

Three-dimensional (3D) imaging and analysis offer new possibilities in preoperative diagnostics and surgical planning. Simultaneous 3D analysis of the joint angles and the patellofemoral anatomy allow for a realistic assessment of bony pathologies in patients with patellofemoral complaints. This study aims to develop a standardized and validated assessment of the 3D patellofemoral morphology and to establish reference ranges.

METHODS

Thirteen patellofemoral anatomic landmarks were defined on 3D bone models of the lower limbs based on computer tomography data and evaluated regarding inter- and intra-observer variability. Further, 60 3D models of the lower limbs of young subjects without any previous knee operation/injury were assessed and rescaled reference values for relevant patellofemoral indices were obtained.

RESULTS

The mean inter- and intra-observer deviation of all landmarks was below 2.3 mm. The interobserver intraclass correlation coefficient (ICC) was between 0.8 and 1.0 and the intra-observer ICC between 0.68 and 0.99 for all patellofemoral parameters. The calculated reference ranges are: Insall-Salvati index 1.0-1.4; patella tilt 6-18°; patella shift -4 to 3 mm; patella facet angle 118-131°; sulcus angle 141-156°; trochlear depth 3-6 mm; tibial-tuberosity to trochlear groove distance(TT-TG) 2D 14-21 mm; TT-TG 3D 11-18 mm; lateral trochlear inclination 13-23°; trochlear facet angle 43-65°.

CONCLUSION

The demonstrated 3D analysis of the patellofemoral anatomy can be performed with high inter- and intra-observer correlation. Applying the obtained reference ranges and using existing 3D assessment tools for lower limb alignment, a preoperative 3D analysis and planning for complex knee procedures now is possible.

Peer victimisation and depression among gender conforming and non-conforming Thai adolescents

Like most low- and middle-income countries, Thailand is facing an increasing burden of depressive disorders among adolescents, but research and services for them are largely neglected. This study explored the association between types of peer victimisation, gender non-conformity, health risk behaviours, and depressive symptoms among Thai students aged 13-18 years. Overall, prevalence of depressive symptoms was 14.7% (95% CI: 12.6-15.6), 12.2% (95% CI: 9.5-13.9) among male students and 16.5% (95% CI: 13.8-18.0) among female students. Among both sexes, social and sexual victimisation in the past month were strongly associated with depressive symptoms in the past week. Gender non-conforming female adolescents, as well as male and female adolescents who had experienced sexual and social victimisation, had a high burden of depressive symptoms. Mental health professionals and educators working with young people in Thailand should consider assessment for clinically significant depressive disorders.

Illicit Drug Use and Social Victimization among Thai Sexual and Gender Minority Adolescents

Objectives: We examined the prevalence of lifetime illicit drug use and social victimization, and their association, among sexual and gender minority (SGM) and non-SGM Thai adolescents. Methods: In 2013, we conducted a school-based national survey among students grades 7-12 (aged 13-20 years) from 15 secondary schools (n = 2,070) around Thailand. We classified adolescents with same-sex attraction, sexual or gender non-conforming identities as SGM. Generalized estimating equations were used to estimate the odds of illicit drug use by SGM and non-SGM status. Results: Prevalence of lifetime illicit drug use was significantly higher among SGM adolescents than non-SGM adolescents (10.3 vs. 5.3%), but did not differ between those with same-sex attraction and SGM identity (10.3 vs. 10.8%). Among non-SGM adolescents, general social victimization, sexual experience and any school truancy were associated with lifetime illicit drug use (OR = 2.59, 95% CI: 1.53, 4.38; OR = 6.59, 95% CI: 4.90, 8.86; and OR = 4.93, 95% CI: 3.13, 7.75, respectively). Among SGM adolescents, SGM-based social victimization, depressive symptomology and suicidal ideation were associated with lifetime illicit drug use (OR = 3.17, 95% CI: 2.03, 4.95; OR = 5.03, 95% CI: 2.32, 10.90; and OR = 5.03, 95% CI: 2.76, 9.16, respectively). Conclusions: SGM adolescents have higher burden of illicit drug use. Moreover, illicit drug use among SGM adolescents is indicative of depressive symptomology and suicidal ideation. Tailored and comprehensive programs are needed to reduce the gap in burden of illicit drug use between SGM and non-SGM adolescents.

Three-dimensional assessment of lower limb alignment: Accuracy and reliability

INTRODUCTION

Three-dimensional (3D) surgical planning and patient-specific implants are becoming increasingly popular in orthopedics and trauma surgery. In contrast to the established and standardized alignment assessment on two-dimensional (2D) long standing radiographs (LSRs) there is neither a standardized nor a validated protocol for the analysis of 3D bone models of the lower limb. This study aimed to create a prerequisite for pre-operative planning.

METHODS

According to 2D analysis and after meticulous research, 24 landmarks were defined on 3D bone models obtained from computed axial tomography (CT) scans for a 3D alignment assessment. Three observers with different experience levels performed the test three different times on three specimens. Intraobserver and interobserver variability of the landmarks and the intraclass correlation coefficient (ICC) of the resulting axes and joint angles were evaluated.

RESULTS

Overall, the intraobserver and interobserver variability was low, with a mean deviation <5 mm for all landmarks. The ICC of all joint angles and axis deviations was >0.8, except for tibial torsion (ICC = 0.69). All knee joint angles showed excellent ICC (>0.95).

CONCLUSIONS

Using the defined landmarks, a standardized 3D alignment assessment with low intraobserver and interobserver variability and high ICC values for the knee joint angles can be performed regardless of examiner's experience. The described method serves as a reliable standardized protocol for a 3D malalignment test of the lower limb. Three-dimensional pre-operative analysis might enhance understanding of deformities and lead to a new focus in surgical planning.

Ensuring Inclusion of Adolescent Key Populations at Higher Risk of HIV Exposure: Recommendations for Conducting Biological Behavioral Surveillance Surveys

Ending acquired immune deficiency syndrome (AIDS) depends on greater efforts to reduce new human immunodeficiency virus (HIV) infections and prevent AIDS-related deaths among key populations at highest HIV risk, including males who have sex with males, sex workers, and people who inject drugs. Although adolescent key populations (AKP) are disproportionately affected by HIV, they have been largely ignored in HIV biological behavioral surveillance survey (BBSS) activities to date. This paper reviews current ethical and sampling challenges and provides suggestions to ensure AKP are included in surveillance activities, with the aim being to enhance evidence-informed, strategic, and targeted funding allocations and programs toward ending AIDS among AKP. HIV BBSS, conducted every few years worldwide among adult key populations, provide information on HIV and other infections’ prevalence, HIV testing, risk behaviors, program coverage, and when at least three of these surveys are conducted, trend data with which to evaluate progress. We provide suggestions and recommendations on how to make the case to ethical review boards to involve AKP in surveillance while assuring that AKP are properly protected. We also describe two widely used probability sampling methods, time location sampling and respondent driven sampling, and offer considerations of feature modifications when sampling AKP. Effectively responding to AKP’s HIV and sexual risks requires the inclusion of AKP in HIV BBSS activities. The implementation of strategies to overcome barriers to including AKP in HIV BBSS will result in more effective and targeted prevention and intervention programs directly suited to the needs of AKP.

Correlates of Forced Sex Among Young Men Who Have Sex With Men in Yangon and Monywa, Myanmar

Forced sex at an early age is associated with a variety of negative factors including increased illness, high-risk sexual and substance-use behaviors, and mental and psychological stress. These sequelae may be compounded for men who have sex with men (MSM), especially young MSM and those with feminine gender identity and expression. This survey examined the prevalence and associations of forced sex among young MSM in two cities in Myanmar. In 2013-2014, surveys using respondent-driven sampling collected data on 200 young MSM in Yangon and 200 in Monywa. One quarter of young MSM in Yangon and 21 % in Monywa reported ever experiencing forced sex. In a multivariable model, having problems with family members and having any MSM friends with many partners had higher odds of experiencing forced sex. Having maternal acceptance of same-sex attraction (compared to acceptance by both parents) and becoming aware of their same-sex attraction at or above the age of 16 had lower odds of experiencing forced sex. Focused research is needed to understand the family and other social dynamics affecting vulnerability to forced sex, as well as specific sexual risks associated with forced sex among young MSM, including HIV acquisition and transmission risks.

Recent HIV Testing Among Young Men Who Have Sex with Men in Bangkok and Chiang Mai: HIV Testing and Prevention Strategies Must Be Enhanced in Thailand

HIV infection among men who have sex with men, particularly in Thai urban settings and among younger cohorts, is escalating. HIV testing and counseling (HTC) are important for prevention and obtaining treatment and care. We examine data from a 2013 survey of males, 15-24 years, reporting past-year sex with a male and living in Bangkok or Chiang Mai. Almost three quarters of young MSM (YMSM) in Bangkok and only 27 % in Chiang Mai had an HIV test in the previous year. Associations for HIV testing varied between cities, although having employment increased the odds of HIV testing for both cities. In Bangkok, family knowledge of same sex attraction and talking to parents/guardians about HIV/AIDS had higher odds of HIV testing. Expanded HTC coverage is needed for YMSM in Chiang Mai. All health centers providing HTC, including those targeting MSM, need to address the specific needs of younger cohorts.

Metabolic and cardiovascular risk profiles and hepatitis C virus infection in rural Egypt

BACKGROUND AND AIMS

To investigate the relationship between lipid profiles and diabetes with past and chronic hepatitis C virus (HCV) infection among village residents of Egypt.

PATIENTS AND METHODS

Fasting lipids and glucose profiles were compared among adults never infected with HCV (negative HCV antibodies), infected in the past (positive HCV antibodies and negative HCV RNA) and chronically infected (positive HCV antibodies and HCV RNA).

RESULTS

Of the 765 participants, 456 (59.6%) were female, and median age was 40 (range 25-88) years. Chronic HCV infection was present in 113 (14.8%) and past infection in 67 (8.8%). After adjustment for age and sex, participants with chronic HCV infection had lower plasma low density lipoproteins (LDL) cholesterol and triglyceride levels compared with those never infected (age and sex adjusted differences (95% CI) were -19.0 (-26.3 to -11.7) mg/dl and -26.2 (-39.0 to -13.3) mg/dl, respectively). In contrast, participants with cleared HCV infection had higher triglyceride levels compared with those never infected (age and sex adjusted difference (95% CI) was +16.0 (0.03 to 31.9) mg/dl). In multivariate analysis, participants with chronic HCV infection were more likely to have diabetes (OR 3.05, 95% CI 1.19 to 7.81) compared with those never infected, independent of LDL cholesterol levels.

CONCLUSION

In conclusion, this community based study has shown that in a single population, chronic HCV infection is associated with glucose intolerance and, despite that, a favourable lipid pattern. An intriguing finding was the high triglyceride levels observed among participants with past infection, suggesting that elevated triglycerides at the time of acute infection may facilitate viral clearance.

Exposure to blood and body fluid: factors associated with non-compliance in follow up HIV testing among health care workers

Due to lack of previous research, this study examined the factors associated with non-compliance in follow up human immunodeficiency virus (HIV) testing among health care workers after blood and/or body fluid exposure. A descriptive correlation design was used with 178 health care workers who did not return for recommended follow up HIV testing post-blood and/or body fluid exposure at three urban hospitals. The 36 question Likert scale was designed to measure the five concepts of the Health Belief Model: susceptibility, seriousness, benefit, barriers, and health motivation. The internal consistency reliability measured .48. Forty five subjects (25%) returned the questionnaire. The most significant factor determined to affect return rate for follow up testing was related to benefits and susceptibility (F = 4.57, df = 2.42, R = .42, P = .02). Return rate was most significantly correlated with the idea of decreasing the chance of dying from acquired immunodeficiency syndrome (AIDS) (r = .31, P = .04). Similar results of recommended future studies may indicate changes in post-exposure education or institutional policies and procedures.

Effects of astrocytes, insulin and insulin-like growth factor I on the survival of motoneurons in vitro

We isolated motoneurons from E15 dissociated mouse spinal cord by density centrifugation and planted them onto poly-ornithine-coated coverslips in a growth medium (DMEM/F12) supplemented with progesterone, transferrin, selenium, horse serum and muscle extract. Under these conditions only 28% of the motoneurons survived for 8 days. When living astrocytes on a separate coverslip were introduced into dishes containing motoneurons, there was a two-fold increase in neuronal survival. The addition of insulin and insulin-like growth factor I (IGF-I) to such cultures alone or together, still further increased motoneuron survival, but this did not happen in the absence of astrocytes. We conclude that (a) astrocytes exert a trophic role in the survival of spinal motoneurons, (b) the effect does not require physical contact of the cells, and (c) insulin and IGF-1 have neurotrophic activity for motoneurons, an effect possibly mediated by living astrocytes.

Azaarenes in Recent Marine Sediments

Chemical fractionation and mass spectral probe distillation reveal the presence in recent marine sediments of a complex assemblage of nitrogen-containing aromatic compounds. These azaarenes range from three- to eight-membered rings, with homologs containing up to eight alkyl carbons. In their composition, and presumably in their origin in natural fires, they resemble the aromatic hydrocarbons found in the same sediments. The analytical, geochemical, and environmental implications of these findings are discussed.

Oil Pollution: Persistence and Degradation of Spilled Fuel Oil

In September 1969, approximately 600 metric tons of number 2 fueloil were spilled in Buzzards Bay, Massachusetts. Two years later, fuel oil hydrocarbons still persisted in the marsh and in offshore sediments. Hydrocarbon degradation is slow, especially below the immediate sediment surface and appears to proceed principally through microbial utilization of alkanes and through partial dissolution of the lower-boiling aromatic hydrocarbons. The boiling range of the spilled oil and the relative abundances of homologous hydrocarbons (for example, phytane and pristane) have been well preserved. The findings are in agreement with the known geochemical stability of hydrocarbons. Fuel oil is an appreciable fraction of whole crude oil. This fact suggests that oil products and crude oils have a considerable environmental persistence.