Unreliable numbers: error and harm induced by bad design can be reduced by better design

Number entry is a ubiquitous activity and is often performed in safety- and mission-critical procedures, such as healthcare, science, finance, aviation and in many other areas. We show that Monte Carlo methods can quickly and easily compare the reliability of different number entry systems. A surprising finding is that many common, widely used systems are defective, and induce unnecessary human error. We show that Monte Carlo methods enable designers to explore the implications of normal and unexpected operator behaviour, and to design systems to be more resilient to use error. We demonstrate novel designs with improved resilience, implying that the common problems identified and the errors they induce are avoidable

Pratique du judo à haut niveau après resurfaçage de hanche

National audienceBackground et hypothèse:La pratique sportive après arthroplastie de hanche est une demande fonctionnelle de plus en plus fréquente. Certains sports comme le judo sont mal évalués en termes de possibilité après prothèse et considérés comme à risque important de luxation, descellement et révision. Le but de ce travail était d’évaluer le retour au judo après resurfaçage de hanche (RTH) en termes de délai et de niveau de pratique chez une population experte et de déterminer le taux de complication chirurgicale.Matériel et méthode:Il s’agit d’une étude observationnelle rétrospective incluant tous les judokas licenciés avec un niveau expert (≥ ceinture noire 3e Dan) opérés d’un RTH. Tous les patients ont répondu à un questionnaire dédié détaillant leur niveau de pratique du judo (international, national, régional, loisir), le type de pratique (enseignement, loisir technique, loisir compétition), le grade précis (dan), le volume horaire hebdomadaire et le délai postopératoire de reprise du judo. Les caractéristiques de la reprise ont été analysées (judo technique, au sol, combat).RésultatsSoixante-sept RTH chez 60 patients ont été réalisé chez judokas internationaux pour 11 cas, nationaux pour 3, régionaux pour 8 et loisir pour 38. Concernant les grades, la série était constituée de 18 cas 3e Dan, 18 cas 4e Dan, 7 cas 5e Dan et 17 cas hauts gradés (6e et 7e Dan, 5 et 12 cas respectivement). Le recul moyen était de 65,3 mois (9,9–111,9). Tous les scores cliniques mettaient en évidence une amélioration cliniquement et statistiquement significative. Sur les 60 patients, 53 avaient repris le judo au dernier recul (89,5 %) au délai moyen de 4 mois (2–7) postopératoire pour le judo technique, 6 mois (3–10) pour le judo au sol et 7 mois (3–12) pour les combats. Les motifs d’absence de reprise du judo étaient : pour 3 patients un changement volontaire de sport, pour 2 patients une appréhension psychologique et pour 2 patients une douleur inguinale résiduelle. Le volume horaire hebdomadaire était : de 0,9 heures par semaine (0–5) en préopératoire à 5 heures (2–18) (p < 0,001) en postopératoire.Conclusion :Le RTH dans une population de judokas de haut niveau technique permet un retour au sport sans complications de type fracture, luxation ou descellement à court terme

High-level judo practice after hip resurfacing

International audienceBackground and hypothesis: The ability to participate in sports after hip arthroplasty is increasingly being requested by patients. The possibilities of participating in sports such as judo after hip arthroplasty have not been explored sufficiently even though these sports are associated with a high risk of loosening, dislocation or revision. The aim of this study was to evaluate the return to judo after hip resurfacing arthroplasty (HRA) in terms of time and level of practice in an expert population and to determine the surgical complication rate. Materials and methods: This was a retrospective observational study of all licensed judo practitioners at an expert level (&gt;= black belt 3rd Dan) who underwent HRA. Patients filled out a sport-specific questionnaire that captured their level of judo practice (international, national, regional, recreational), type of practice (teaching, technical recreational, competitive recreational), dan grade, weekly volume of practice and time elapsed after surgery before resuming judo. The features of the return to judo were analyzed (technical, ground, combat). Results: Sixty-seven HRA were implanted in 60 patients: 11 were international judokas, 3 were national, 8 were regional and 38 were recreational. The case series consisted of 18 patients who were 3rd Dan, 18 were 4th Dan, 7 were 5th Dan, 5 were 6th Dan and 12 were 7th Dan. The average follow-up was 65.3 months (range 9.9-11.9). All the clinical scores pointed to clinically and statistically significant improvement. Of the 60 patients, 53 had resumed judo at the final assessment (90%) after a mean of 4 months (2-7) for technical judo, 6 months (3-10) for ground judo and 7 months (3-12) for combat judo. Of those who did not resume their judo practice, 3 patients voluntarily changed sports, 2 had psychological apprehension and 2 had residual groin pain. The weekly volume of practice preoperatively was 0.9 hours (0-5) and postoperatively it reached 5 hours (2-18) (P &lt; 0.001). Conclusion: HRA in a population of high-level judokas allows for return to sport practice without short term complications such as fracture, dislocation or loosening. (C) 2020 Elsevier Masson SAS. All rights reserved

Are spinoglenoid ganglion cysts early markers of glenohumeral arthritis?

International audienceHypothesis The objective of this study was to improve our understanding of the pathogenesis and symptoms of ganglion cysts (GCs) in the spinoglenoid notch. Two hypotheses were tested: (1) the labral tears responsible for these cysts are mainly degenerative and nontraumatic, (2) spinoglenoid cysts are early magnetic resonance image (MRI) markers of eccentric posterior glenoid wear. Materials and methods This was a descriptive diagnostic study. Patients were included when a spinoglenoid cyst was discovered after complaints of pain in the posterosuperior aspect of the shoulder. MRI and arthroscopy were used to classify the glenoid GC and characterize the glenohumeral joint. The GCs were classified into 1 of 3 types: GC0 (isolated cyst), GC1 (cyst and associated labral lesion), and GC2 (cyst and associated labral and cartilage lesion). Results Twenty patients (average age, 43 years) were included between 2000 and 2014. There were 7 GC0, 8 GC1, and 5 GC2 type cysts. Isolated labral tears (GC1) were always located posteriorly, without anterior extension or glenoid detachment. The humeral subluxation index was above 55% in 75% of shoulders, including all of the type GC2 shoulders. The 5 GC2 shoulders had type B1, B2, or C glenoids. Conclusions The management of paraglenoid labral cysts must go beyond addressing the suprascapular nerve compression related to traumatic labral detachment, and surgeons should look automatically for associated degenerative joint damage. The diagnosis of GCs should be supplemented by humeral subluxation index measurement on computed tomography scan or MRI, and the patient should be informed that joint-related posterior shoulder pain might persist in cases of GC1 and GC2. Level of evidence Basic Science Study; Anatomy; Imaging and In Viv

Virtual reality simulation training improve diagnostic knee arthroscopy and meniscectomy skills: a prospective transfer validity study

Abstract Purpose Limited data exist on the actual transfer of skills learned using a virtual reality (VR) simulator for arthroscopy training because studies mainly focused on VR performance improvement and not on transfer to real word (transfer validity). The purpose of this single‐blinded, controlled trial was to objectively investigate transfer validity in the context of initial knee arthroscopy training. Methods For this study, 36 junior resident orthopaedic surgeons (postgraduate year one and year two) without prior experience in arthroscopic surgery were enrolled to receive standard knee arthroscopy surgery training (NON‐VR group) or standard training plus training on a hybrid virtual reality knee arthroscopy simulator (1 h/month) (VR group). At inclusion, all participants completed a questionnaire on their current arthroscopic technical skills. After 6 months of training, both groups performed three exercises that were evaluated independently by two blinded trainers: i) arthroscopic partial meniscectomy on a bench‐top knee simulator; ii) supervised diagnostic knee arthroscopy on a cadaveric knee; and iii) supervised knee partial meniscectomy on a cadaveric knee. Training level was determined with the Arthroscopic Surgical Skill Evaluation Tool (ASSET) score. Results Overall, performance (ASSET scores) was better in the VR group than NON‐VR group (difference in the global scores: p < 0.001, in bench‐top meniscectomy scores: p = 0.03, in diagnostic knee arthroscopy on a cadaveric knee scores: p = 0.04, and in partial meniscectomy on a cadaveric knee scores: p = 0.02). Subgroup analysis by postgraduate year showed that the year‐one NON‐VR subgroup performed worse than the other subgroups, regardless of the exercise. Conclusion This study showed the transferability of the technical skills acquired by novice residents on a hybrid virtual reality simulator to the bench‐top and cadaveric models. Surgical skill acquired with a VR arthroscopy surgical simulator might safely improve arthroscopy competences in the operating room, also helping to standardise resident training and follow their progress. Level of evidence

A recurrent prosthetic joint infection caused by Erysipelothrix rhusiopathiae: case report and literature review

International audienceProsthetic knee joint infection caused by Erysipelothrix rhusiopathiae is uncommon and only one case of recurrent infection has previously been described. Here, we describe the case of a 77-year-old male patient who was admitted to the teaching hospital of Rennes (France) with bilateral and nocturnal gonalgia evolving for 1 month. He had bilateral knee prosthesis 10 years ago, and a history of large B-cell lymphoma in remission. A diagnosis of infective endocarditis, with prosthetic knee infection, was made, with positive cultures of synovial fluids and blood; colonies of E. rhusiopathiae were identified by MALDI-TOF MS. Initial treatment involved debridement, implant retention surgery and intravenous amoxicillin (12 g day(-1)) for 6 weeks with gentamicin 3 mg kg(-1) day(-1) added for the first 4 days. One year later, a second episode of E. rhusiopathiae infection occurred, suggesting a recurrence or reinfection due to the same bacterial species. The patient was finally cured after a two-stage exchange with a cemented articulated spacer and a 3 month course of amoxicillin (12 g day(-1), iv). Different characteristics of E. rhusiopathiae infection were discussed, with a review of all cases of prosthetic joint infections caused by Erysipelothrix species. This case highlights the need for a long-term survey of patients, and a good knowledge of their environment to avoid any risk of reinfection

Virtual reality simulation training improve diagnostic knee arthroscopy and meniscectomy skills: a prospective transfer validity study

International audiencePurpose: Limited data exist on the actual transfer of skills learned using a virtual reality (VR) simulator for arthroscopy training because studies mainly focused on VR performance improvement and not on transfer to real word (transfer validity). The purpose of this single-blinded, controlled trial was to objectively investigate transfer validity in the context of initial knee arthroscopy training.Methods: For this study, 36 junior resident orthopaedic surgeons (postgraduate year one and year two) without prior experience in arthroscopic surgery were enrolled to receive standard knee arthroscopy surgery training (NON-VR group) or standard training plus training on a hybrid virtual reality knee arthroscopy simulator (1 h/month) (VR group). At inclusion, all participants completed a questionnaire on their current arthroscopic technical skills. After 6 months of training, both groups performed three exercises that were evaluated independently by two blinded trainers: i) arthroscopic partial meniscectomy on a bench-top knee simulator; ii) supervised diagnostic knee arthroscopy on a cadaveric knee; and iii) supervised knee partial meniscectomy on a cadaveric knee. Training level was determined with the Arthroscopic Surgical Skill Evaluation Tool (ASSET) score.Results: Overall, performance (ASSET scores) was better in the VR group than NON-VR group (difference in the global scores: p &lt; 0.001, in bench-top meniscectomy scores: p = 0.03, in diagnostic knee arthroscopy on a cadaveric knee scores: p = 0.04, and in partial meniscectomy on a cadaveric knee scores: p = 0.02). Subgroup analysis by postgraduate year showed that the year-one NON-VR subgroup performed worse than the other subgroups, regardless of the exercise.Conclusion: This study showed the transferability of the technical skills acquired by novice residents on a hybrid virtual reality simulator to the bench-top and cadaveric models. Surgical skill acquired with a VR arthroscopy surgical simulator might safely improve arthroscopy competences in the operating room, also helping to standardise resident training and follow their progress