Re-cementing in revision total hip replacement

Removal of well-fixed cement at revision surgery risks bone loss, cortical perforation and fracture, is time-consuming, technically demanding and carries increased risks for the patient. The cement-in-cement technique avoids these problems and when used appropriately has given favourable results at our centre when used on both the femoral and acetabular sides of the articulation. A modified technique has also been used in selected cases of infection and peri-prosthetic fracture. This chapter highlights the results to date and the operative techniques employed. It is essential to recognise that this technique relies fundamentally on the presence of a well-fixed cement mantle, and it is imperative that the criteria laid out are adhered to in order to achieve success. If there is loosening or lysis on the femoral side extending distal to the lesser trochanter or around more than just the periphery of the acetabular cement mantle, then alternative revision techniques should be employed.

Integrity, attribution, and exploitation : contractual and normative moral rights protection in open licensing

Over the last twenty years, the use of open content licenses has become increasingly and surprisingly popular. The use of such licences challenges the traditional incentive-based model of exclusive rights under copyright. Instead of providing a means to charge for the use of particular works, what seems important is mitigating against potential personal harm to the author and, in some cases, preventing non-consensual commercial exploitation. It is interesting in this context to observe the primacy of what are essentially moral rights over the exclusionary economic rights. The core elements of common open content licences map somewhat closely to continental conceptions of the moral rights of authorship. Most obviously, almost all free software and free culture licences require attribution of authorship. More interestingly, there is a tension between social norms developed in free software communities and those that have emerged in the creative arts over integrity and commercial exploitation. For programmers interested in free software, licence terms that prohibit commercial use or modification are almost completely inconsistent with the ideological and utilitarian values that underpin the movement. For those in the creative industries, on the other hand, non-commercial terms and, to a lesser extent, terms that prohibit all but verbatim distribution continue to play an extremely important role in the sharing of copyright material. While prohibitions on commercial use often serve an economic imperative, there is also a certain personal interest for many creators in avoiding harmful exploitation of their expression – an interest that has sometimes been recognised as forming a component of the moral right of integrity. One particular continental moral right – the right of withdrawal – is present neither in Australian law or in any of the common open content licences. Despite some marked differences, both free software and free culture participants are using contractual methods to articulate the norms of permissible sharing. Legal enforcement is rare and often prohibitively expensive, and the various communities accordingly rely upon shared understandings of acceptable behaviour. The licences that are commonly used represent a formalised expression of these community norms and provide the theoretically enforceable legal baseline that lends them legitimacy. The core terms of these licences are designed primarily to alleviate risk in sharing and minimise transaction costs in sharing and using copyright expression. Importantly, however, the range of available licences reflect different optional balances in the norms of creating and sharing material. Generally, it is possible to see that, stemming particularly from the US, open content licences are fundamentally important in providing a set of normatively accepted copyright balances that reflect the interests sought to be protected through moral rights regimes. As the cost of creation, distribution, storage, and processing of expression continues to fall towards zero, there are increasing incentives to adopt open content licences to facilitate wide distribution and reuse of creative expression. Thinking of these protocols not only as reducing transaction costs but of setting normative principles of participation assists in conceptualising the role of open content licences and the continuing tensions that permeate modern copyright law.

Does the protection of vulnerable children require a system of mandatory reporting of abuse and neglect? [An issues paper for the New Zealand Government Green Paper for vulnerable children]

In this Issues Paper, I raise some key points relevant for any government which is considering its child protection and family welfare policy. In particular, I will raise questions about whether a form of legislative reporting duty is required, and if so, what consequences this has for child protection. The context of child maltreatment - and each form of maltreatment: physical abuse, sexual abuse, psychological or emotional abuse, and neglect - is extremely complex, and the overarching question of how to deal with these phenomena involve challenging normative, economic and practical questions. There are no easy or perfect solutions. Nor, often, is there the amount and quality of evidence available on which public policy approaches should be devised. However, from the best evidence about the history of this context, from research conducted in this field, and from the best evidence available about the nature, incidence and effects of different subtypes of maltreatment, some observations can be made which may help to inform deliberations. I outline 10 key issues related to mandatory reporting legislation while being mindful of the New Zealand context. My view, based on both research evidence and a concern to protect and promote children’s interests, and society’s interests, is that reporting laws in some form are necessary and can contribute substantially to child protection and enhancing family and community health and wellbeing. However, they are only one necessary part of a sound child protection system, being a method of tertiary and secondary prevention, and primary prevention efforts must also be prioritised. Moreover, it is essential that if a legislative reporting duty is enacted, it must be designed carefully and implemented soundly, and it must be integrated within a properly resourced child protection and family welfare system.

Application of an appearance-based intervention to improve sun protection outcomes of outdoor workers in Queensland, Australia

Outdoor workers are exposed to high levels of ultraviolet radiation (UVR) and may thus be at greater risk to experience UVR-related health effects such as skin cancer, sun burn, and cataracts. A number of intervention trials (n=14) have aimed to improve outdoor workers’ work-related sun protection cognitions and behaviours. Only one study however has reported the use of UV-photography as part of a multi-component intervention. This study was performed in the USA and showed long-term (12 months) improvements in work-related sun protection behaviours. Intervention effects of the other studies have varied greatly, depending on the population studied, intervention applied, and measurement of effect. Previous studies have not assessed whether: - Interventions are similarly effective for workers in stringent and less stringent policy organisations; - Policy effect is translated into workers’ leisure time protection; - Implemented interventions are effective in the long-term; - The facial UV-photograph technique is effective in Australian male outdoor workers without a large additional intervention package, and; - Such interventions will also affect workers’ leisure time sun-related cognitions and behaviours. Therefore, the present Protection of Outdoor Workers from Environmental Radiation [POWER]-study aimed to fill these gaps and had the objectives of: a) assessing outdoor workers’ sun-related cognitions and behaviours at work and during leisure time in stringent and less stringent sun protection policy environments; b) assessing the effect of an appearance-based intervention on workers’ risk perceptions, intentions and behaviours over time; c) assessing whether the intervention was equally effective within the two policy settings; and d) assessing the immediate post-intervention effect. Effectiveness was described in terms of changes in sun-related risk perceptions and intentions (as these factors were shown to be main precursors of behaviour change in many health promotion theories) and behaviour. The study purposefully selected and recruited two organisations with a large outdoor worker contingent in Queensland, Australia within a 40 kilometre radius of Brisbane. The two organisations differed in the stringency of implementation and reinforcement of their organisational sun protection policy. Data were collected from 154 male predominantly Australian born outdoor workers with an average age of 37 years and predominantly medium to fair skin (83%). Sun-related cognitions and behaviours of workers were assessed using self-report questionnaires at baseline and six to twelve months later. Variation in follow-up time was due to a time difference in the recruitment of the two organisations. Participants within each organisation were assigned to an intervention or control group. The intervention group participants received a one-off personalised Skin Cancer Risk Assessment Tool [SCRAT]-letter and a facial UV-photograph with detailed verbal information. This was followed by an immediate post-intervention questionnaire within three months of the start of the study. The control group only received the baseline and follow-up questionnaire. Data were analysed using a variety of techniques including: descriptive analyses, parametric and non-parametric tests, and generalised estimating equations. A 15% proportional difference observed was deemed of clinical significance, with the addition of reported statistical significance (p<0.05) where applicable. Objective 1: Assess and compare the current sun-related risk perceptions, intentions, behaviours, and policy awareness of outdoor workers in stringent and less stringent sun protection policy settings. Workers within the two organisations (stringent n=89 and less stringent n=65) were similar in their knowledge about skin cancer, self efficacy, attitudes, and social norms regarding sun protection at work and during leisure time. Participants were predominantly in favour of sun protection. Results highlighted that compared to workers in a less stringent policy organisation working for an organisation with stringent sun protection policies and practices resulted in more desirable sun protection intentions (less willing to tan p=0.03) ; actual behaviours at work (sufficient use of upper and lower body protection, headgear, and sunglasses (p<0.001 for all comparisons), and greater policy awareness (awareness of repercussions if Personal Protective Equipment (PPE) was not used, p<0.001)). However the effect of the work-related sun protection policy was found not to extend to leisure time sun protection. Objective 2: Compare changes in sun-related risk perceptions, intentions, and behaviours between the intervention and control group. The effect of the intervention was minimal and mainly resulted in a clinically significant reduction in work-related self-perceived risk of developing skin cancer in the intervention compared to the control group (16% and 32% for intervention and control group, respectively estimated their risk higher compared to other outdoor workers: , p=0.11). No other clinical significant effects were observed at 12 months follow-up. Objective 3: Assess whether the intervention was equally effective in the stringent sun protection policy organisation and the less stringent sun protection policy organisation. The appearance-based intervention resulted in a clinically significant improvement in the stringent policy intervention group participants’ intention to protect from the sun at work (workplace*time interaction, p=0.01). In addition to a reduction in their willingness to tan both at work (will tan at baseline: 17% and 61%, p=0.06, at follow-up: 54% and 33%, p=0.07, stringent and less stringent policy intervention group respectively. The workplace*time interaction was significant p<0.001) and during leisure time (will tan at baseline: 42% and 78%, p=0.01, at follow-up: 50% and 63%, p=0.43, stringent and less stringent policy intervention group respectively. The workplace*time interaction was significant p=0.01) over the course of the study compared to the less stringent policy intervention group. However, no changes in actual sun protection behaviours were found. Objective 4: Examine the effect of the intervention on level of alarm and concern regarding the health of the skin as well as sun protection behaviours in both organisations. The immediate post-intervention results showed that the stringent policy organisation participants indicated to be less alarmed (p=0.04) and concerned (p<0.01) about the health of their skin and less likely to show the facial UV-photograph to others (family p=0.03) compared to the less stringent policy participants. A clinically significantly larger proportion of participants from the stringent policy organisation reported they worried more about skin cancer (65%) and skin freckling (43%) compared to those in the less stringent policy organisation (46%,and 23% respectively , after seeing the UV-photograph). In summary the results of this study suggest that the having a stringent work-related sun protection policy was significantly related to for work-time sun protection practices, but did not extend to leisure time sun protection. This could reflect the insufficient level of sun protection found in the general Australian population during leisure time. Alternatively, reactance caused by being restricted in personal decisions through work-time policy could have contributed to lower leisure time sun protection. Finally, other factors could have also contributed to the less than optimal leisure time sun protection behaviours reported, such as unmeasured personal or cultural barriers. All these factors combined may have lead to reduced willingness to take proper preventive action during leisure time exposure. The intervention did not result in any measurable difference between the intervention and control groups in sun protection behaviours in this population, potentially due to the long lag time between the implementation of the intervention and assessment at 12-months follow-up. In addition, high levels of sun protection behaviours were found at baseline (ceiling effect) which left little room for improvement. Further, this study did not assess sunscreen use, which was the predominant behaviour assessed in previous effective appearance-based interventions trials. Additionally, previous trials were mainly conducted in female populations, whilst the POWER-study’s population was all male. The observed immediate post-intervention result could be due to more emphasis being placed on sun protection and risks related to sun exposure in the stringent policy organisation. Therefore participants from the stringent policy organisation could have been more aware of harmful effects of UVR and hence, by knowing that they usually protect adequately, not be as alarmed or concerned as the participants from the less stringent policy organisation. In conclusion, a facial UV-photograph and SCRAT-letter information alone may not achieve large changes in sun-related cognitions and behaviour, especially of assessed 6-12 months after the intervention was implemented and in workers who are already quite well protected. Differences found between workers in the present study appear to be more attributable to organisational policy. However, against a background of organisational policy, this intervention may be a useful addition to sun-related workplace health and safety programs. The study findings have been interpreted while respecting a number of limitations. These have included non-random allocation of participants due to pre-organised allocation of participants to study group in one organisation and difficulty in separating participants from either study group. Due to the transient nature of the outdoor worker population, only 105 of 154 workers available at baseline could be reached for follow-up. (attrition rate=32%). In addition the discrepancy in the time to follow-up assessment between the two organisations was a limitation of the current study. Given the caveats of this research, the following recommendations were made for future research: - Consensus should be reached to define "outdoor worker" in terms of time spent outside at work as well as in the way sun protection behaviours are measured and reported. - Future studies should implement and assess the value of the facial UV-photographs in a wide range of outdoor worker organisations and countries. - More timely and frequent follow-up assessments should be implemented in intervention studies to determine the intervention effect and to identify the best timing of booster sessions to optimise results. - Future research should continue to aim to target outdoor workers’ leisure time cognitions and behaviours and improve these if possible. Overall, policy appears to be an important factor in workers’ compliance with work-time use of sun protection. Given the evidence generated by this research, organisations employing outdoor workers should consider stringent implementation and reinforcement of a sun protection policy. Finally, more research is needed to improve ways to generate desirable behaviour in this population during leisure time.

Seasonal variation in cardiovascular disease risk factors in a subarctic population : the Tromso Study 1979-2008

Background Seasonal changes in cardiovascular disease (CVD) risk factors may be due to exposure to seasonal environmental variables like temperature and acute infections or seasonal behavioural patterns in physical activity and diet. Investigating the seasonal pattern of risk factors should help determine the causes of the seasonal pattern in CVD. Few studies have investigated the seasonal variation in risk factors using repeated measurements from the same individual, which is important as individual and population seasonal patterns may differ. Methods The authors investigated the seasonal pattern in systolic and diastolic blood pressure, heart rate, body weight, total cholesterol, triglycerides, high-density lipoprotein cholesterol, C reactive protein and fibrinogen. Measurements came from 38 037 participants in the population-based cohort, the Tromsø Study, examined up to eight times from 1979 to 2008. Individual and population seasonal patterns were estimated using a cosinor in a mixed model. Results All risk factors had a highly statistically significant seasonal pattern with a peak time in winter, except for triglycerides (peak in autumn), C reactive protein and fibrinogen (peak in spring). The sizes of the seasonal variations were clinically modest. Conclusions Although the authors found highly statistically significant individual seasonal patterns for all risk factors, the sizes of the changes were modest, probably because this subarctic population is well adapted to a harsh climate. Better protection against seasonal risk factors like cold weather could help reduce the winter excess in CVD observed in milder climates.

Environmental rights or a right to the environment? Exploring the nexus between human rights and environmental protection.

The importance of the environment to the fulfilment of human rights is widely accepted at international law. What is less well-accepted is the proposition that we, as humans, possess rights to the environment beyond what is necessary to support our basic human needs. The suggestion that a human right to a healthy environment may be emerging at international law raises a number of theoretical and practical challenges for human rights law, with such challenges coming from both within and outside the human rights discourse. It is argued that human rights law can make a positive contribution to environmental protection, but the precise nature of the connection between the environment and human rights warrants more critical analysis. This short paper considers the different ways that the environment is conceptualised in international human rights law and analyses the proposition that a right to a healthy environment is emerging. It identifies some of the challenges which would need to be overcome before such a right could be recognised, including those which draw on the disciplines of deep ecology and earth jurisprudence.

Battling in a virtual world: a proposal for increased copyright protection of multimedia products in Australia

This article discusses the adequacy of copyright protection afforded to multimedia products pursuant to the Copyright Act 1968 (Cth) and in response to international obligations. The paper critically evaluates the effect that the most recent amendments to the Copyright Act have had on the protection of copyright in multimedia products. An outline of some practical measures of protection available to copyright owners as alternatives or complements to the current statutory regime is provided, ultimately concluding that the current legislative protection is ineffective. The paper closes by considering possible future reform by way of statutory amendments to the Copyright Act aimed at increasing protection of copyright in multimedia products.

Revision total hip replacement using the cement-in-cement technique for the acetabular component : technique and results for 60 hips

The technique of femoral cement-in-cement revision is well established, but there are no previous series reporting its use on the acetabular side at the time of revision total hip arthroplasty. We describe the surgical technique and report the outcome of 60 consecutive cement-in-cement revisions of the acetabular component at a mean follow-up of 8.5 years (range 5-12 years). All had a radiologically and clinically well fixed acetabular cement mantle at the time of revision. 29 patients died. No case was lost to follow-up. The 2 most common indications for acetabular revision were recurrent dislocation (77%) and to compliment a femoral revision (20%). There were 2 cases of aseptic cup loosening (3.3%) requiring re-revision. No other hip was clinically or radiologically loose (96.7%) at latest follow-up. One case was re-revised for infection, 4 for recurrent dislocation and 1 for disarticulation of a constrained component. At 5 years, the Kaplan-Meier survival rate was 100% for aseptic loosening and 92.2% (95% CI; 84.8-99.6%) with revision for all causes as the endpoint. These results support the use of the cement-in-cement revision technique in appropriate cases on the acetabular side. Theoretical advantages include preservation of bone stock, reduced operating time, reduced risk of complications and durable fixation.

Evaluation of the cost-effectiveness of strategies claiming to reduce the risk of surgical site infections following primary total hip arthroplasty

Background Total hip arthroplasty (THA) is a commonly performed procedure and numbers are increasing with ageing populations. One of the most serious complications in THA are surgical site infections (SSIs), caused by pathogens entering the wound during the procedure. SSIs are associated with a substantial burden for health services, increased mortality and reduced functional outcomes in patients. Numerous approaches to preventing these infections exist but there is no gold standard in practice and the cost-effectiveness of alternate strategies is largely unknown. Objectives The aim of this project was to evaluate the cost-effectiveness of strategies claiming to reduce deep surgical site infections following total hip arthroplasty in Australia. The objectives were: 1. Identification of competing strategies or combinations of strategies that are clinically relevant to the control of SSI related to hip arthroplasty 2. Evidence synthesis and pooling of results to assess the volume and quality of evidence claiming to reduce the risk of SSI following total hip arthroplasty 3. Construction of an economic decision model incorporating cost and health outcomes for each of the identified strategies 4. Quantification of the effect of uncertainty in the model 5. Assessment of the value of perfect information among model parameters to inform future data collection Methods The literature relating to SSI in THA was reviewed, in particular to establish definitions of these concepts, understand mechanisms of aetiology and microbiology, risk factors, diagnosis and consequences as well as to give an overview of existing infection prevention measures. Published economic evaluations on this topic were also reviewed and limitations for Australian decision-makers identified. A Markov state-transition model was developed for the Australian context and subsequently validated by clinicians. The model was designed to capture key events related to deep SSI occurring within the first 12 months following primary THA. Relevant infection prevention measures were selected by reviewing clinical guideline recommendations combined with expert elicitation. Strategies selected for evaluation were the routine use of pre-operative antibiotic prophylaxis (AP) versus no use of antibiotic prophylaxis (No AP) or in combination with antibiotic-impregnated cement (AP & ABC) or laminar air operating rooms (AP & LOR). The best available evidence for clinical effect size and utility parameters was harvested from the medical literature using reproducible methods. Queensland hospital data were extracted to inform patients’ transitions between model health states and related costs captured in assigned treatment codes. Costs related to infection prevention were derived from reliable hospital records and expert opinion. Uncertainty of model input parameters was explored in probabilistic sensitivity analyses and scenario analyses and the value of perfect information was estimated. Results The cost-effectiveness analysis was performed from a health services perspective using a hypothetical cohort of 30,000 THA patients aged 65 years. The baseline rate of deep SSI was 0.96% within one year of a primary THA. The routine use of antibiotic prophylaxis (AP) was highly cost-effective and resulted in cost savings of over $1.6m whilst generating an extra 163 QALYs (without consideration of uncertainty). Deterministic and probabilistic analysis (considering uncertainty) identified antibiotic prophylaxis combined with antibiotic-impregnated cement (AP & ABC) to be the most cost-effective strategy. Using AP & ABC generated the highest net monetary benefit (NMB) and an incremental $3.1m NMB compared to only using antibiotic prophylaxis. There was a very low error probability that this strategy might not have the largest NMB (<5%). Not using antibiotic prophylaxis (No AP) or using both antibiotic prophylaxis combined with laminar air operating rooms (AP & LOR) resulted in worse health outcomes and higher costs. Sensitivity analyses showed that the model was sensitive to the initial cohort starting age and the additional costs of ABC but the best strategy did not change, even for extreme values. The cost-effectiveness improved for a higher proportion of cemented primary THAs and higher baseline rates of deep SSI. The value of perfect information indicated that no additional research is required to support the model conclusions. Conclusions Preventing deep SSI with antibiotic prophylaxis and antibiotic-impregnated cement has shown to improve health outcomes among hospitalised patients, save lives and enhance resource allocation. By implementing a more beneficial infection control strategy, scarce health care resources can be used more efficiently to the benefit of all members of society. The results of this project provide Australian policy makers with key information about how to efficiently manage risks of infection in THA.

Personalised electronic messages to improve sun protection in young adults

The incidence of all skin cancers, including melanoma, continues to rise. It is well known that ultraviolet (UV) radiation is the main environmental risk factor for skin cancer, and excessive exposure at a young age increases the risk of developing skin cancer. The aim of this study was to determine the acceptability and feasibility of delivering sun protection messages via electronic media such as short message services (SMS) to people 18-40 years, and explore factors associated with their acceptability. Overall, 80% of participants agreed that they would like to receive some form of sun protection advice; of these, 20% prefer to receive it via SMS and 42% via email. Willingness to receive electronic messages about the UV index was associated with being unsure about whether a suntanned person would look healthy and greater use of sun protection in the past. Careful attention to message framing and timing of message delivery and focus on short-term effects of sun exposure such as sunburn and skin ageing should increase the acceptability of such messages to young people. We conclude that sun protection messages delivered to young adults via electronic media appear feasible and acceptable.

Total Solar Eclipse in North Queensland 14 Nov 2012

This article is a brief introduction to the total solar eclipse Wed 14 November 2012 in north Queensland that will be seen in a narrow strip of land just 140 km wide in the vicinity of Cairns.