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Jukka S. Jurvelin

Bio: Jukka S. Jurvelin is an academic researcher from University of Eastern Finland. The author has contributed to research in topics: Cartilage & Bone mineral. The author has an hindex of 77, co-authored 423 publications receiving 20441 citations. Previous affiliations of Jukka S. Jurvelin include University of Bern & Utrecht University.


Papers
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Journal ArticleDOI
TL;DR: Values of the elastic parameters of the cartilage are dependent on the measurement technique in use and may depend on the indenter size in use, as well as the equilibrium response of articular cartilage under unconfined and confined compression.

427 citations

Journal ArticleDOI
TL;DR: The current results reveal the close connection between the laminar T2 structure and the collagen architecture in histologic zones.
Abstract: It has been suggested that orientational changes in the collagen network of articular cartilage account for the depthwise T2 anisotropy of MRI through the magic angle effect. To investigate the relationship between laminar T2 appearance and collagen organization (anisotropy), bovine osteochondral plugs (N = 9) were T2 mapped at 9.4T with cartilage surface normal to the static magnetic field. Collagen fibril arrangement of the same samples was studied with polarized light microscopy, a quantitative technique for probing collagen organization by analyzing its ability to rotate plane polarized light, i.e., birefringence (BF). Depthwise variation of safranin O-stained proteoglycans was monitored with digital densitometry. The spatially varying cartilage T2 followed the architectural arrangement of the collagen fibril network: a linear positive correlation between T2 and the reciprocal of BF was established in each sample, with r = 0.91 +/- 0.02 (mean +/- SEM, N = 9). The current results reveal the close connection between the laminar T2 structure and the collagen architecture in histologic zones.

426 citations

Journal ArticleDOI
TL;DR: The prevailing view is that osteoarthrosis starts from the cartilage surface through PG depletion and fibrillation of the superficial collagen network, and it has been suggested that the initial structural changes take place in the subchondral bone, especially when the joint is exposed to an impact type of loading.
Abstract: Joints are functional units that transmit mechanical loads between contacting bones during normal daily or specialized activities, e.g., sports. All components of the joint, i.e. articular cartilage, bone, muscles, ligaments/tendons and nerves, participate in load transmission. Failure in any of these components can cause joint malfunction, which, in turn, may lead to accumulation of damage in other joint components. Mechanical forces have great influence on the synthesis and rate of turnover of articular cartilage molecules, such as proteoglycans (PGs). Regular cyclic loading of the joint enhances PG synthesis and makes cartilage stiff. On the other hand, loading appears to have less evident effects on the articular cartilage collagen fibril network. Continuous compression of the cartilage diminishes PG synthesis and causes damage of the tissue through necrosis. The prevailing view is that osteoarthrosis (OA) starts from the cartilage surface through PG depletion and fibrillation of the superficial collagen network. It has also been suggested that the initial structural changes take place in the subchondral bone, especially when the joint is exposed to an impact type of loading. This in turn would create an altered stress pattern on joint surfaces, which leads to structural damage and mechanical failure of articular cartilage. The importance of the neuromuscular system to the initiation and progression of OA is still poorly understood. Many surgical extra- and intra-articular procedures have been used for the treatment of OA. Although some of the new methods, such as autologous chondrocyte transplantation and mosaicplasty, have given good clinical results, it is reasonable to emphasize that the methods still are experimental and more controlled studies are needed.

357 citations

Journal ArticleDOI
TL;DR: An optical method for the visualization of boundaries of cylindrical bovine humeral head articular cartilage disks, immersed in physiological solution, and compressed in unconfined geometry revealed that the lateral expansion, especially during the initial phase of relaxation, was inhomogeneous through the tissue depth.

355 citations

Journal ArticleDOI
TL;DR: It is considered that moderate running exercise locally alters the biological properties of young articular cartilage at regions bearing the highest loading surplus.

307 citations


Cited by
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Journal ArticleDOI
TL;DR: These interventions were more effective in people at higher risk of falling, including those with severe visual impairment, and home safety interventions appear to be more effective when delivered by an occupational therapist.
Abstract: As people get older, they may fall more often for a variety of reasons including problems with balance, poor vision, and dementia. Up to 30% may fall in a year. Although one in five falls may require medical attention, less than one in 10 results in a fracture. This review looked at the healthcare literature to establish which fall prevention interventions are effective for older people living in the community, and included 159 randomised controlled trials with 79,193 participants. Group and home-based exercise programmes, usually containing some balance and strength training exercises, effectively reduced falls, as did Tai Chi. Overall, exercise programmes aimed at reducing falls appear to reduce fractures. Multifactorial interventions assess an individual's risk of falling, and then carry out treatment or arrange referrals to reduce the identified risks. Overall, current evidence shows that this type of intervention reduces the number of falls in older people living in the community but not the number of people falling during follow-up. These are complex interventions, and their effectiveness may be dependent on factors yet to be determined. Interventions to improve home safety appear to be effective, especially in people at higher risk of falling and when carried out by occupational therapists. An anti-slip shoe device worn in icy conditions can also reduce falls. Taking vitamin D supplements does not appear to reduce falls in most community-dwelling older people, but may do so in those who have lower vitamin D levels in the blood before treatment. Some medications increase the risk of falling. Three trials in this review failed to reduce the number of falls by reviewing and adjusting medications. A fourth trial involving family physicians and their patients in medication review was effective in reducing falls. Gradual withdrawal of a particular type of drug for improving sleep, reducing anxiety, and treating depression (psychotropic medication) has been shown to reduce falls. Cataract surgery reduces falls in women having the operation on the first affected eye. Insertion of a pacemaker can reduce falls in people with frequent falls associated with carotid sinus hypersensitivity, a condition which causes sudden changes in heart rate and blood pressure. In people with disabling foot pain, the addition of footwear assessment, customised insoles, and foot and ankle exercises to regular podiatry reduced the number of falls but not the number of people falling. The evidence relating to the provision of educational materials alone for preventing falls is inconclusive.

3,124 citations

01 Jan 2016
TL;DR: This paper critically analyzes the deployment issues of best three proposals considering trade-off between security functions and performance overhead and concludes that none of them is deployable in practical scenario.
Abstract: Border Gateway Protocol (BGP) is the protocol backing the core routing decisions on the Internet. It maintains a table of IP networks or 'prefixes' which designate network reachability among autonomous systems (AS). Point of concern in BGP is its lack of effective security measures which makes Internet vulnerable to different forms of attacks. Many solutions have been proposed till date to combat BGP security issues but not a single one is deployable in practical scenario. Any security proposal with optimal solution should offer adequate security functions, performance overhead and deployment cost. This paper critically analyzes the deployment issues of best three proposals considering trade-off between security functions and performance overhead.

2,691 citations

Journal ArticleDOI
01 Jul 2018-Medicine
TL;DR: CEUS can help RMI to make a more effective differential diagnosis of the adnexal mass and further validation by additional multicenter prospective trials is required.

2,549 citations

Journal ArticleDOI
TL;DR: The objectives of this study are to review the long-term consequences of injuries to the anterior cruciate ligament and menisci, the pathogenic mechanisms, and the causes of the considerable variability in outcome, and to strive toward a comparable level of quality of evidence in surgical treatment of knee injuries.
Abstract: The objectives of this study are to review the long-term consequences of injuries to the anterior cruciate ligament and menisci, the pathogenic mechanisms, and the causes of the considerable variability in outcome. Injuries of the anterior cruciate ligament and menisci are common in both athletes and the general population. At 10 to 20 years after the diagnosis, on average, 50% of those with a diagnosed anterior cruciate ligament or meniscus tear have osteoarthritis with associated pain and functional impairment: the young patient with an old knee. These individuals make up a substantial proportion of the overall osteoarthritis population. There is a lack of evidence to support a protective role of repair or reconstructive surgery of the anterior cruciate ligament or meniscus against osteoarthritis development. A consistent finding in a review of the literature is the often poor reporting of critical study variables, precluding data pooling or a meta-analysis. Osteoarthritis development in the injured joints is caused by intra-articular pathogenic processes initiated at the time of injury, combined with long-term changes in dynamic joint loading. Variation in outcome is reinforced by additional variables associated with the individual such as age, sex, genetics, obesity, muscle strength, activity, and reinjury. A better understanding of these variables may improve future prevention and treatment strategies. In evaluating medical treatment, we now expect large randomized clinical trials complemented by postmarketing monitoring. We should strive toward a comparable level of quality of evidence in surgical treatment of knee injuries. In instances in which a randomized clinical trial is not feasible, natural history and other observational cohort studies need to be as carefully designed and reported as the classic randomized clinical trial, to yield useful information.

2,014 citations

Journal ArticleDOI
TL;DR: The unique and complex structure of articular cartilage makes treatment and repair or restoration of the defects challenging for the patient, the surgeon, and the physical therapist.
Abstract: Articular cartilage is the highly specialized connective tissue of diarthrodial joints. Its principal function is to provide a smooth, lubricated surface for articulation and to facilitate the transmission of loads with a low frictional coefficient (Figure 1). Articular cartilage is devoid of blood vessels, lymphatics, and nerves and is subject to a harsh biomechanical environment. Most important, articular cartilage has a limited capacity for intrinsic healing and repair. In this regard, the preservation and health of articular cartilage are paramount to joint health. Figure 1. Gross photograph of healthy articular cartilage in an adult human knee. Injury to articular cartilage is recognized as a cause of significant musculoskeletal morbidity. The unique and complex structure of articular cartilage makes treatment and repair or restoration of the defects challenging for the patient, the surgeon, and the physical therapist. The preservation of articular cartilage is highly dependent on maintaining its organized architecture.

1,835 citations