No abstract

Billions of screws are inserted by surgeons each year, making them the most commonly inserted implant. When using non-locking screws, insertion technique is decided by the surgeon, including how much to tighten each screw. The aims of this study were to assess, through a systematic review, the screw tightness and rate of material stripping produced by surgeons and the effect of different variables related to screw insertion. Twelve studies were included, with 260 surgeons inserting a total of 2793 screws; an average of 11 screws each, although only 1510 screws have been inserted by 145 surgeons where tightness was measured – average tightness was 78±10% for cortical (n = 1079) and 80±6% for cancellous screw insertions (n = 431). An average of 26% of all inserted screws irreparably damaged and stripped screw holes, reducing the construct pullout strength. Furthermore, awareness of bone stripping is very poor, meaning that screws must be considerably overtightened before a surgeon will typically detect it. Variation between individual surgeons’ ability to optimally insert screws was seen, with some surgeons stripping more than 90% of samples and others hardly any. Contradictory findings were seen for the relationship between the tightness achieved and bone density. The optimum tightness for screws remains unknown, thus subjectively chosen screw tightness, which varies greatly, remains without an established target to generate the best possible construct for any given situation. Work is needed to establish these targets, and to develop methods to accurately and repeatably achieve them. Cite this article: EFORT Open Rev 2020;5:26-36. DOI: 10.1302/2058-5241.5.180066

Based on the good to excellent functional mid-term follow-up results of this study, the pararectus approach can be recommended as sufficient alternative single access to address displaced acetabular fractures involving the anterior column, independent of patients' age.

Traditionally, it had been assumed that meta-representational Theory of Mind (ToM) emerges around the age of 4 when children come to master standard false belief (FB) tasks. More recent research with various implicit measures, though, has documented much earlier competence and thus challenged the traditional picture. In interactive FB tasks, for instance, infants have been shown to track an interlocutor's false or true belief when interpreting her ambiguous communicative acts (Southgate et al . 2010 Dev. Sci. 13 , 907–912. ( doi:10.1111/j.1467-7687.2009.00946.x )). However, several replication attempts so far have produced mixed findings (e.g. Dörrenberg et al . 2018 Cogn. Dev. 46 , 12–30. ( doi:10.1016/j.cogdev.2018.01.001 ); Grosse Wiesmann et al. 2017 Dev. Sci. 20 , e12445. ( doi:10.1111/desc.12445 ); Király et al . 2018 Proc. Natl Acad. Sci. USA 115 , 11 477–11 482. ( doi:10.1073/pnas.1803505115 )). Therefore, we conducted a systematic replication study, across two laboratories, of an influential interactive FB task (the so-called ‘Sefo’ tasks by Southgate et al . 2010 Dev. Sci. 13 , 907–912. ( doi:10.1111/j.1467-7687.2009.00946.x )). First, we implemented close direct replications with the original age group (17-month-olds) and compared their performance to those of 3-year-olds. Second, we designed conceptual replications with modifications and improvements regarding pragmatic ambiguities for 2-year-olds. Third, we validated the task with explicit verbal test versions in older children and adults. Results revealed the following: the original results could not be replicated, and there was no evidence for FB understanding measured by the Sefo task in any age group except for adults. Comparisons to explicit FB tasks suggest that the Sefo task may not be a sensitive measure of FB understanding in children and even underestimate their ToM abilities. The findings add to the growing replication crisis in implicit ToM research and highlight the challenge of developing sensitive, reliable and valid measures of early implicit social cognition.

Introduction Multiple sclerosis is a chronic inflammatory, degenerative disease of the central nervous system manifesting at first with relapses in about 85% of cases. In Germany, intravenous therapy with high-dose corticosteroids is the treatment standard of acute relapses. The treatment leads to a faster reduction of symptoms in about 25 of 100 treated patients but has no proven long-term benefits over placebo treatment. Intravenous treatment is not superior to oral treatment. Therefore, informed decisions on relapse management are required. An earlier randomised controlled trial showed that evidence-based patient information and education on relapse management leads to more informed decisions and more relapses not treated or treated with oral corticosteroids. This study aims to evaluate whether a web-based relapse management programme will positively change relapse management and strengthen autonomy in people with multiple sclerosis. Methods The pragmatic double-blind randomised controlled trial is accompanied by a mixed-methods process evaluation and a health economic evaluation and follows the UK Medical Research Council guidance on developing and evaluating complex interventions. A total of 188 people with possible or relapsing-remitting multiple sclerosis with ≥ 1 relapse within the last year and/or ≥ 2 relapses within the last 2 years will be recruited and randomised using blocks. The intervention group receives a web- and dialogue-based decision aid on relapse management, a nurse-led webinar and access to a monitored chat forum. The control group receives standard information, which will be made available via the same online platform as the intervention. The primary endpoint is the proportion of relapses not treated or treated with oral corticosteroids. Key secondary endpoints are the annualised relapse rate, decision-making, empowerment, quality of life and cost-effectiveness. Facilitators and barriers will be assessed by mixed-methods process evaluation measures. The study ends when 81 relapses have been documented or after 24 months of observation per individual patient. Analyses will follow the intention-to-treat principle. Discussion We hypothesise that the intervention will enhance patient empowerment and have a positive impact on patients’ relapse management. Trial registration ClinicalTrials.govNCT04233970. Registered on 18 January 2020