Biomechanics of Lumbar Spine Injury in Road Barrier Collision-Finite Element Study.

Literature and field data from CIREN database have shown that lumbar spine injuries occur during car crashes. There are multiple hypotheses regarding how they occur; however, there is no biomechanical explanation for these injuries during collisions with road safety barriers (RSBs). Therefore, the objective of this study was to investigate the mechanics of vertebral fractures during car collisions with concrete RSBs. The finite element method was used for the numerical simulations. The global model of the car collision with the concrete RSB was created. The lumbar spine kinematics were extracted from the global simulation and then applied as boundary conditions to the detailed lumbar spine model. The results showed that during the collision, the occupant was elevated, and then dropped during the vehicle landing. This resulted in axial compression forces 2.6 kN with flexion bending moments 34.7 and 37.8 Nm in the L2 and L3 vertebrae. It was shown that the bending moment is the result of the longitudinal force on the eccentricity. The lumbar spine index for the L1-L5 section was 2.80, thus indicating a lumbar spine fracture. The minimum principal strain criterion of 7.4% and damage variable indicated L2 and L3 vertebrae and the inferior part of L1, as those potentially prone to fracture. This study found that lumbar spine fractures could occur as a consequence of vehicle landing during a collision with a concrete RSB mostly affecting the L1-L3 lumbar spine section. The fracture was caused by a combination of axial forces and flexion bending moments.

High meniscal slope angle as a risk factor for meniscal allograft extrusion.

A meniscal graft extrusion is still an unresolved problem that affects most patients after a meniscal transplantation. Despite the advances in surgical techniques, together with the improved methods for a meniscal allograft sizing, success is only observed in up to 75% of patients after they experience a meniscal allograft transplantation. Because a meniscal extrusion is associated with a cartilage deterioration and the progression of osteoarthritis there is a great interest in how to prevent this phenomenon. The crucial factor for the minimisation of a meniscal allograft extrusion is by perfectly matching the implant. Most methods for a meniscal allograft sizing only focus on assessing the length and the width of the meniscus. Even though there is some evidence that there is a relationship between the shape of the meniscus in a cross-sectional plane and the meniscal extrusion, any of the planning methods do not take this factor into consideration. Although there is a large variability of meniscus shapes in cross-section, we hypothesise that by taking the meniscal slope into account during surgical planning, as well as performing the correct adjustments of this particular parameter, we can diminish the risk of a meniscal allograft extrusion.

Mangiferin: A promising therapeutic agent for rheumatoid arthritis treatment.

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by synovial hyperplasia and progressive joint destruction. Despite aggressive treatment with anti-rheumatic drugs, progressive destruction of joints continues to occur in RA patients, who subsequently require joint surgery. A lot of evidence suggest that fibroblast-like synovial cells (FLS) play crucial role in joint degradation and the propagation of inflammation in RA. The expansion of fibroblast populations in the joint results primarily from the inhibition of pro-apoptotic pathways, rather than large scale proliferation. Because multiple factors, which contribute to fibroblast activation and enhance their destructive potential, are under control of transcription factor NF-κB, this pathway presents an interesting target for RA therapy. However, due to the lack of specificity, NF-κB inhibitors may exert severe side effects. Given the above, there has recently been more interest in natural substances of plant origin which are regarded as a safe alternatives for synthetic drugs. Mangiferin, the naturally occurring polyphenol with excellent anti-inflammatory and antioxidative properties, exhibits strong pro-apoptotic effect toward synoviocytes isolated from human synovia. Moreover, it shows no cytotoxicity toward cultivated chondrocytes and reduces the levels of matrix metalloproteinases. Considering that mangiferin is a natural constituent of foods and traditional herbal medicines, showing fewer adverse effects and low toxicity, we hypothesize that it may prove effective in the treatment of RA and prevention against joint destruction.

Different distribution of CD4 and CD8 T cells in synovial membrane and peripheral blood of rheumatoid arthritis and osteoarthritis patients.

Rheumatoid arthritis (RA) and osteoarthritis (OA) are chronic diseases associated with morphological joint changes. Synovial membrane (SM) involvement was established for RA, but the data for OA are limited, because OA is usually regarded as noninflammatory disease. Changes in immune system in RA are not limited to joints, and the significant role of T cells of peripheral blood (PB) is not disputable. However, there is still an open debate about PB immunological profile in OA. Therefore, we decided to measure the distribution of CD4+ and CD8+ T cells, regarding CD28 expression, both in PB and SM of RA and OA patients, on the same day. Altogether, eleven RA patients, 11 OA patients and similar numbers of age-matched healthy controls were included into the study. Flow cytometry was used for T cells subpopulation distinguishing and quantification; monoclonal antibodies against CD3, CD4, CD8 and CD28 with different fluorochromes were used for stainings. The RA patients had significantly higher percentage of CD3+4+ cells in PB as compared to OA patients and relevant control group. Both within the CD4+ and CD8+ compartments, significantly lower percentages of cells bearing the CD28 marker were found in the PB of OA as compared to RA patients. The proportion of CD3+CD4+ cells in SM was dependent on age of OA patients, older OA patients had significantly higher value of their SM/blood ratio than RA patients. Older OA subjects were also characterized by higher values of the SM/blood ratio of both CD4+CD28+ and CD8+CD28+ subpopulations than RA or younger OA patients. In conclusion, in contrast to the traditional view of OA disease, our results give support to the hypothesis that OA may also (like RA) be a disease with a local immunological involvement.