Prevalence of helmet use by users of bicycles, push scooters, inline skates and skateboards in Toronto and the surrounding area in the absence of comprehensive legislation: an observational study.

BACKGROUND: Legislation in the province of Ontario, Canada, mandates users under the age of 18 to wear a helmet when they ride a bicycle, and legislation has been shown to significantly increase rates of bicycle helmet use. Legislation does not exist in Ontario for older bicyclists or for users of other non-motorised modes of transportation, and there are no current data available regarding rates of helmet use in these categories. This study was designed to determine the prevalence of helmet use among users of bicycles, skateboards, push scooters and inline skates in Toronto, Ontario, and the surrounding area. Further analysis was performed to examine factors associated with helmet use. METHODS: We performed a cross-sectional, observational study. Three trained, stationary observers captured 6038 users of bicycles (5783), skateboards (77), inline skates (165) and push scooters (13) in the summer of 2009. Observations were separated into three time periods capturing commuters, midday users and recreational users. A general linear model was used to assess the factors associated with helmet use among bicyclists. RESULTS: Helmets were worn by 48.9% of all users observed and 50.0% of all bicyclists. Among bicyclists, females were more likely to wear helmets than males (prevalence ratio 1.27, 95% CI 1.17 to 1.36), while children were significantly more likely to wear helmets than adults (prevalence ratio 1.17, 95% CI 1.37 to 2.15). Significant behavioural variation was observed among users during the three observation periods (p<0.001), with commuters being the most likely to wear a helmet. CONCLUSION: In the absence of comprehensive legislation encompassing all ages of users, only half of users of non-motorised, wheeled transportation devices are choosing to wear a helmet to protect against traumatic brain injury. Implementation of evidence-based strategies to increase helmet use, such as the introduction of legislation encompassing all ages and all equipment, is required.

Osteosynthesis Technique for Periprosthetic Femoral Fractures: A Case of Interprosthetic Fracture Between a Total Knee Arthroplasty and a Dynamic Hip Screw.

Periprosthetic fractures remain a challenging component of every trauma practice. Total joints have become common in very elderly patients, creating a variety of implanted stress risers that make subsequent fractures unique challenges to address. This creates the need to build a construct that will allow for early weight bearing while trying to reduce the potential for further fractures in the same bone. A minimally invasive submuscular approach with long periprosthetic locking plates can be used for a periprosthetic femoral fracture.

Patient-Reported Outcome Measures for Patellofemoral Instability: a Critical Review.

PURPOSE OF REVIEW: The purpose of this paper was to review the current psychometric properties of patient-reported outcome measures that are commonly used for patients with patellofemoral instability. This review provides evidence to guide the selection of subjective outcome measures for assessing outcomes in clinical care and research studies. RECENT FINDINGS: At the present time, there are two patient-reported outcome measures that have been designed for, and tested on, large cohorts of patellofemoral instability patients, the Banff Patella Instability Instrument (BPII) and the Norwich Patellar Instability Score (NPI). The BPII is a wholistic quality of life outcome measure and the NPI is a symptom score. The use of disease-specific outcome measures such as the BPII and NPI, in combination with generic knee, functional activity, and/or psychological outcome measures that have been proven to be valid and reliable for the patellofemoral instability population, is most likely to provide a well-rounded evaluation of treatment outcomes.

Magnesium Sulfate Salt Solutions and Ices Fail to Protect Serratia liquefaciens from the Biocidal Effects of UV Irradiation under Martian Conditions.

The growth of Serratia liquefaciens has been demonstrated under martian conditions of 0.7 kPa (7 mbar), 0°C, and CO2-enriched anoxic atmospheres (Schuerger et al., 2013, Astrobiology 13:115-131), but studies into the survivability of cells under hypersaline conditions that are likely to be encountered on Mars are lacking. Serratia liquefaciens cells were suspended in aqueous MgSO4 solutions, or frozen brines, and exposed to terrestrial (i.e., 101.3 kPa, 24°C, O2/N2-normal atmosphere) or martian (i.e., 0.7 kPa, -25°C, CO2-anoxic atmosphere) conditions to assess the roles of MgSO4 and UV irradiation on the survival of S. liquefaciens. Four solutions were tested for their capability to attenuate martian UV irradiation in both liquid and frozen forms: sterile deionized water (SDIW), 10 mM PO4 buffer, 5% MgSO4, and 10% MgSO4. None of the solutions in either liquid or frozen forms provided enhanced protection against martian UV irradiation. Sixty minutes of UV irradiation reduced cell densities from 2.0 × 106 cells/mL to less than 10 cells/mL for both liquid and frozen solutions. In contrast, 3-4 mm of a Mars analog soil were sufficient to attenuate 100% of UV irradiation. Results suggest that terrestrial microorganisms may not survive on Sun-exposed surfaces on Mars, even if the cells are embedded in frozen martian brines composed of MgSO4. However, if dispersed microorganisms can be covered by only a few millimeters of dust or regolith, long-term survival is probable. Key Words: Hypobaria-Mars-Planetary protection-Brines. Astrobiology 17, 401-412.