The extent and risk of knee injuries in children aged 9-14 with Generalised Joint Hypermobility and knee joint hypermobility:the CHAMPS-study Denmark

BACKGROUND: Generalised Joint Hypermobility (GJH) is suggested as an aetiological factor for knee injuries in adolescents and adults. It is presumed that GJH causes decreased joint stability, thereby increasing the risk of knee injuries during challenging situations like jumping and landing. The aim was to study the extent and risk of knee injuries in children with GJH and knee hypermobility. METHODS: In total, 999 children (9–14 years) were tested twice during spring 2012 and 2013 with Beighton´s Tests (BT) for hypermobility, a 0–9 scoring system. GJH was classified with cut-point ≥5/9 on both test rounds. On basis of weekly cell phone surveys of knee pain, children requiring clinical examination were seen. Traumatic and overuse knee injuries were registered by WHO ICD-10 diagnoses. Logistic regression and Poisson regression models with robust standard errors were used to examine the association between GJH and knee injuries, taking into account clustering on school class levels. RESULTS: Totally, 36 children were classified GJH on both test rounds. Overuse knee injuries were the most frequent injury type (86 %), mainly apophysitis for both groups (61 %), other than patella-femoral pain syndrome for the control group (13 %). For traumatic knee injuries, distortions and contusions were most frequent in both groups (51 % resp. 36 %), besides traumatic lesions of knee tendons and muscles for the control group (5 %). No significant association was found between overuse knee injuries and GJH with/without knee hypermobility (OR 0.69, p = 0.407 resp. OR 0.75, p = 0.576) or traumatic knee injuries and GJH with/without knee hypermobility (OR 1.56, p = 0.495 resp. OR 2.22, p = 0.231). CONCLUSIONS: Apophysitis, distortions and contusions were the most frequent knee injuries. Despite the relatively large study, the number of children with GJH and knee injuries was low, with no significant increased risk for knee injuries for this group. This questions whether GJH is a clinically relevant risk factor for knee injuries in school children aged 9–14 years. A fluctuation in the individual child´s status of GJH between test rounds was observed, suggesting that inter- and intra-tester reproducibility of BT as well as growth may be considered important confounders to future studies of children with GJH

Single leg mini squat:an inter-tester reproducibility study of children in the age of 9-10 and 12-14 years presented by various methods of kappa calculation

BACKGROUND: Multiple studies suggest that reduced postural orientation is a possible risk factor for both patello-femoral joint pain (PFP) and rupture of the anterior cruciate ligament (ACL). In order to prevent PFP and ACL injuries in adolescent athletes, it is necessary to develop simple and predictive screening tests to identify those at high risk. Single Leg Mini Squat (SLMS) is a functional and dynamic real-time screening test, which has shown good validity and reproducibility in evaluation of postural orientation of the knee in an adult population. The aim of this study was to determine the inter-tester reproducibility of SLMS in the age group of 9–10 and 12–14 years by evaluating postural orientation of the ankle, knee, hip and trunk. Further on, this study exemplify the divergence of kappa values when using different methods of calculating kappa for the same dataset. METHODS: A total of 72 non-injured children were included in the study. Postural orientation of the ankle, knee, hip and trunk for both legs was determined by two testers using a four-point scale (ordinal, 0–3). Prevalence, overall agreement as well as four different methods for calculating kappa were evaluated: linear weighted kappa in comparison with un-weighted kappa, prevalence-adjusted bias-adjusted kappa (PABAK) and quadratic weighted kappa. RESULTS: The linear weighted kappa values ranged between 0.54-0.86 (overall agreement 0.86-0.97), reflecting a moderate to almost perfect agreement. When calculating un-weighted kappa (with and without PABAK) and quadratic weighted kappa, the results spread between 0.46-0.88, 0.50-0.94, and 0.76-0.95, reflecting the various results when using different methods of kappa calculation. CONCLUSIONS: The Single Leg Mini Squat test has moderate to almost perfect reproducibility in children aged 9–10 and 12–14 years when evaluating postural orientation of the ankles, knees, hips and trunk, based on the excellent strength of agreement as presented by linear weighted kappa. The inconsistency in results when using different methods of kappa calculation demonstrated the linear weighted kappa being generally 15% lower than the quadratic weighted values. On average, prevalence-adjusted bias-adjusted kappa increased the un-weighted kappa values by 7% and 12% by children aged 9–10 and 12–14, respectively

Microclimatic temperatures increase the potential for vector-borne disease transmission in the Scandinavian climate

We quantified the difference between the meteorological temperature recorded by the Danish Meteorological Institute (DMI) weather stations and the actual microclimatic temperatures at two or three different heights at six potential insect habitats. We then compared the impact of the hourly temperature on the extrinsic incubation period (EIP) of six pathogens. Finally, we developed a regression model, enabling us to predict the microclimatic temperatures of different habitats based on five standard meteorological parameters readily available from any meteorological institution. Microclimatic habitats were on average 3.5–5 °C warmer than the DMI recorded temperatures during midday and 1–3 °C cooler at midnight. The estimated EIP for five of the six microclimatic habitats was shorter than the estimates based on DMI temperatures for all pathogens studied. The microclimatic temperatures also predicted a longer season for virus development compared to DMI temperatures. Based on DMI data of hourly temperature, solar radiation, wind speed, rain and humidity, we were able to predict the microclimatic temperature of different habitats with an R2 of 0.87–0.96. Using only meteorological temperatures for vector-borne disease transmission models may substantially underestimate both the daily potential for virus development and the duration of the potential transmission season