Differences in subchondral bone plate and cartilage thickness between women with anterior cruciate ligament reconstructions and uninjured controls.

OBJECTIVE: Anterior cruciate ligament (ACL) tears increase early onset osteoarthritis (OA) risk leading to cartilage and bone degradation. While the contribution of bone in OA development is unclear, evidence suggests that bone changes accompany cartilage degradation. This study aims to assess if regions with differences in subchondral bone plate thickness have differences in cartilage thickness when comparing ACL reconstructed (ACLR) knees of women ≥5 years post-injury to contralateral and controls with uninjured knees. DESIGN: Magnetic resonance imaging (MRI) assessed cartilage and high resolution peripheral quantitative computed tomography (HR-pQCT) assessed subchondral bone in both knees. Multimodal 3D image registration aligned anatomy. Maps of the spatial distribution of thickness on the articular surfaces were generated to compare women with ACL reconstructions to contralateral and controls with uninjured knees. RESULTS: ACLR knees had a thicker subchondral bone plate in the posterior and central lateral femur compared to contralateral knees (10.4% and 4.2% thicker, P = 0.032 and 0.032, W = 108 and 107, respectively) and in the posterior lateral femur compared to control knees (17.1% thicker, P = 0.014, W = 177). Cartilage differences were not detected (P > 0.05) in these regions. CONCLUSIONS: This study demonstrates that subchondral bone plate thickness differences are prominent following knee injury, as measured by HR-pQCT, but no statistically significant differences in cartilage morphology, measured by MRI, were found between ACLR knees compared to contralateral and control knees. These data provide novel insight into post-traumatic knee injuries that may be signs of early OA pathogenesis.

Effect of the lateral rotators on load transfer in the human hip joint revealed by mechanical analysis.

A deeper understanding of load transfer in the human hip joint is of great importance as there is strong evidence that the mechanical loading of the hip has a major effect on the onset and progression of osteoarthritis. In this work, a biomechanical model of the human hip joint is developed which takes the lateral rotators into account. On the basis of a two-dimensional analysis of the human hip joint, the dependencies of the hip joint reaction force and its angle to the vertical are derived. The dependencies can be given as explicit equations. In addition, a numerical finite element analysis has been set up to calculate the contact pressure distribution on the femoral head. The results of this study are not subject-specific and are intended to show qualitative results and relationships of the load transfer behavior. The results of this two-dimensional study show that the lateral rotators have a significant effect on the contact pressure distribution in the human hip joint. Activated lateral rotators shift the maximum contact pressure in the medial direction and the contact pressure at the lateral edge of the contact area is significantly reduced. The results are validated by comparison to results in the literature and subsequently discussed. The results give additional insight into the load transfer behavior of the human hip joint and might be of relevance to investigations on the development of conservative therapies for osteoarthritic hips.

[Lung function testing in children before and after an age-adapted SCUBA dive in a swimming pool]. / Lungenfunktionsmessung bei Kindern vor und nach einem altersadaptierten SCUBA Tauchgang im Schwimmbad.

BACKGROUND: The number of children that SCUBA dive is increasing. Airway narrowing while SCUBA diving can cause dangerous complications like pulmonary barotrauma and arterial gas embolism. Statistics show that children are at an increased risk. Since data are scarce, the goal of this study was to gain new knowledge about acute lung function changes in children while SCUBA diving. MATERIAL AND METHODS: 41 children aged 8 - 14 years underwent lung function testing (spirometry and residual volume measurement) before and after a single age-adapted SCUBA dive in a swimming pool. RESULTS: A significant reduction of the dynamic expiratory lung function parameters FEV (1) (p < 0.01), FEV (1)/VC (p < 0.05), MEF 75 % (p < 0.05), MEF 50 % (p < 0.01) und MEF 25 % (p < 0.05) was measured. No statistically significant change of the residual volume was found. A decrease of FEV (1) > 10 % (12 % - 21 %) was found in 5 children (12.2 %). CONCLUSION: The majority of the children (87.8 %) did not show any relevant lung function changes. Five children had a considerable reduction of FEV (1). Signs indicate the importance of bronchial hyperreactivity (BHR) as a key factor. Children with asthma or BHR should not SCUBA dive. A detailed medical examination is recommended (including an unspecific bronchial provocation test) before starting to dive.

Cortical barrelfields in organotypic slice cultures from rat somatosensory cortex.

We are attempting to determine the factors that influence both the formation and maintenance of barrels in the rodent somatosensory cortex. Cytochrome oxidase histochemistry and Nissl staining were used to identify the presence of barrels in slice cultures of rat cortex. Barrels were observed in sagittally cut slices, in cortical layer IV, from animals aged postnatal day 5-10 that were cultured for at least 10 days. No differences were observed in the barrel pattern from animals at different postnatal ages, or from cortex that was cultured for different lengths of time. In contrast, cortical barrels in tangentially cut sections from similarly aged animals were clearly visible after one day in culture, but they disappeared after two days in culture. These results suggest that intact connections within cortical columns are sufficient to sustain the functional architecture of the somatosensory cortex in vitro.

[Etiology of pathogen-induced changes between the toes in patients working under moist conditions]. / Zur Atiologie der erregerbedingten Zehenzwischenraumveränderungen bei Arbeitern in Feuchtbetrieben.

Referring to recent studies, we discuss the epidemiology of tinea pedis and its position within the range of polyetiological foot infections caused by microbial agents. 201 industrial workers used to wear rubber boots because of moist working conditions were examined with regard to their feet. 107 of them showed clinically altered toe web; in 45 cases, we found ringworm infection (22.4%), in correlation to increased daily wearing time of rubber boots. 85 workers showed colonization of pathogenic bacteria (42.4%), especially gram-negative species (25.8%). Frequently, mixed infections were found. The clinical picture not always allows definite conclusions as to the causal agents. The symptom "maceration" is seen in each of the 3 pathogenic groups of germs (fungi, gram-positive pathogenic cocci, gram-negative bacteria), frequently in bacterial foot infections, especially gram-negative infections. Marked clinical symptoms involve increased infection rates. The predisposing factors to foot infection such as interdigital maceration and the promoting role of rubber boots have been confirmed. The final diagnosis is to be reassured by cultural investigations, in order to set up a specific treatment.