ObjectivesFractures of the proximal femur are a common clinical problem, and a number of orthopaedic devices are available for the treatment of such fractures. The objective of this study was to assess the rotational stability, a common failure predictor, of three different rotational control design philosophies: a screw, a helical blade and a deployable crucifix.MethodsDevices were compared in terms of the mechanical work (W) required to rotate the implant by 6° in a bone substitute material. The substitute material used was Sawbones polyurethane foam of three different densities (0.08 g/cm3, 0.16 g/cm3 and 0.24 g/cm3). Each torsion test comprised a steady ramp of 1°/minute up to an angular displacement of 10°.ResultsThe deployable crucifix design (X-Bolt), was more torsionally stable, compared to both the dynamic hip screw (DHS, p = 0.008) and helical blade (DHS Blade, p= 0.008) designs in bone substitute material representative of osteoporotic bone (0.16 g/cm3 polyurethane foam). In 0.08 g/cm3 density substrate, the crucifix design (X-Bolt) had a higher resistance to torsion than the screw (DHS, p = 0.008). There were no significant differences (p = 0.101) between the implants in 0.24 g/cm3 density bone substitute.ConclusionsOur findings indicate that the clinical standard proximal fracture fixator design, the screw (DHS), was the least effective at resisting torsional load, and a novel crucifix design (X-Bolt), was the most effective design in resisting torsional load in bone substitute material with density representative of osteoporotic bone. At other densities the torsional stability was also higher for the X-Bolt, although not consistently significant by statistical analysis.Cite this article: J. D. Gosiewski, T. P. Holsgrove, H. S. Gill. The efficacy of rotational control designs in promoting torsional stability of hip fracture fixation. Bone Joint Res 2017;6:270–276. DOI: 10.1302/2046-3758.65.BJR-2017-0287.R1.

This paper describes how a small educational technology (edtech) company worked with academics, combining technological expertise, science content expertise, pedagogy and social research methodology to develop and evaluate the effect of video feedback on learners’ ability to answer science questions correctly. The investigation was carried out by the research team in Tassomai as part of their involvement with the EDUCATE programme. The Tassomai team worked with the research mentors in EDUCATE to find the best ways of helping students both to understand science concepts and to help them correctly answer science questions in exams. Findings indicated that, as expected, the video feedback helped learners to answer the question correctly, but also that, after a delay of around one week, a higher proportion of those students were still able to answer the question correctly compared to those in a control group of learners who did not have access to the related instructive video. The collaborative work between the Tassomai research team and the EDUCATE business and research mentors provided an environment to share expertise and channel it to improve Tassomai’s offering to learners. As a result of this study, Tassomai is now investing in the production of more instructive videos to help students understand difficult science concepts, and students will be offered these videos if they are having difficulty in answering the questions correctly.