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Influence of the patellar button thickness on the knee flexion after total knee arthroplasty

Rosso I., Surface C., Antonaci P., Surface F. M., Negretto R. J.

Acta of Bioengineering and Biomechanics

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2018

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Vol. 20, no. 4

121-134

EN

One of the main problems of knee replacement is the limit of knee flexion. This study focuses on the knee implant and the patellar component currently in use in total knee arthroplasty, analyzing the influence of patellar thickness on the degree of knee flexion following surgery. Methods: A kinematics study was performed to evaluate whether an optimal patellar thickness can be identified, which enables the maximum flexion angle to be achieved. Using TC images, a healthy model was built. On this basis, a model of a knee joint which had undergone total knee arthroplasty using a Legion PS prosthesis was constructed. Initially, the standard thickness of patellar implant (9 mm) was used to build the model; then several different patellar implant thicknesses (in the range of 5–15 mm) were analyzed. Results: The results show a non-linear trend: a button thickness of less than 9 mm does not change the flexion angle, whereas a button thickness of over 9 mm results in a loss of flexion. The flexion loss is significant in the first two additions of thicknesses but negligible in the last ones. Conclusions: In the case studied, flexion reduction is not linearly proportional to the patellar thickness. The outcome of total knee arthroplasty is considered to be satisfactory with the standard patellar button. The results of this study could be used to compare the kinematics with other total prosthesis and patellar implants, and should enable the optimization of the patellar residue bone thickness to obtain deep flexion.

2

Excessive tensile strain induced the change in chondrocyte phenot

Zhong D., Chen X., Luo Z.-P.

Acta of Bioengineering and Biomechanics

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2018

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Vol. 20, no. 2

3--10

EN

Chondrocyte extracellular matrix type II collagen and proteoglycans ensure an important compression-bearing structure in synovial joint. However, much more type I collagen is generated in osteoarthritis, which implies the presence of abnormal tensile strain in cartilage. We hypothesize that tensile stress influences chondrocyte phenotype at the cellular level, leading to potential osteoarthritis. Methods: Chondrocytes were stimulated with cyclic excessive tensile (10%) or mild tensile or compressive strain (5%) at 0.5 Hz, 3 h per day for 3 days. Chondrocyte morphology and matrix proteoglycans level was separately determined by Rhodamine phalloidin and toluidine blue staining. The expression of cartilage marker molecules was measured using quantitative reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assays. Results: Chondrocytes demonstrated significant fibroblastic morphology, reduced proliferation and increased apoptosis following exposure to 10% tensile strain. The 10% tensile strain group induced the lowest matrix proteoglycans level. It observably reduced the expression of COL2A1, Acan and SOX9, and increased COL1A1 expression level. The 5% tensile (5% compression) group, maintained the chondrocyte phenotype. Conclusions: The findings identified the effects of different magnitudes of tensile stress on chondrocyte phenotype compared to compressive strain. Further studies on cartilage biomechanical micro-environment might benefit from this study.

3

Analiza zmian struktury i gęstości kości gąbczastej w nasadzie bliższej kości udowej zmienionej zwyrodnieniowo

Burzyńska K., Nikodem A., Słowiński J., Filipiak J.

Aktualne Problemy Biomechaniki

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2015

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z. 9

25--30

PL

Zmiany geometrii kości spowodowane rozwojem osteoartrozy (OA) dotyczą coraz szerszej populacji. Skomplikowany przebieg choroby wymaga prowadzenia dokładniejszych badań mechanizmów powstawania choroby. W pracy przeprowadzono analizę numeryczną przebudowy tkanki gąbczastej kości udowej według dwóch modeli przebudowy (model Tsuboty oraz model Cartera) w zależności od stadium rozwoju choroby zwyrodnieniowej. Pokazano wpływ zmian geometrii nasady na rozkład beleczek kostnych w chorobie zwyrodnieniowej.

EN

Changes in bone geometry caused by development of osteoarthritis (OA) affect more and more people. The complicated course of the disease necessitates a closer studies of mechanisms of the disease. In the paper numerical analysis of remodeling of femur spongy tissue was carried out. Two models of reconstruction were used (Tsubota model and Carter model) depending on the stage of development of osteoarthritis. Impact of changes in geometry of epiphysis on the distribution of trabecular bone in osteoarthritis were analyzed.

4

Badania właściwości stukturalnych i mechanicznych tkanki kostnej zmienionej zwyrodnieniowo

Tomanik M., Nikodem A.

Aktualne Problemy Biomechaniki

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2013

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z. 7

163--168

PL

Celem badań było określenie właściwości mechanicznych oraz strukturalnych tkanki kostnej gąbczastej pochodzącej z nasad bliższych kości udowych. Materiał badawczy pochodził od pacjentów z chorobą zwyrodnieniową o zróżnicowanym stopniu zaawansowania. Porównując wyniki właściwości strukturalnych i mechanicznych próbek pochodzących z różnych regionów nasady bliższej można stwierdzić większe zmiany modułu Younga, DMA, BV/TV, Tb.Th, Tb.N oraz DA w rejonie tkanki kostnej, która znajduje się bezpośrednio pod degradującą się stawową warstwą tkanki chrzęstnej.

EN

It is common known that the cancellous bone is able to change its structure under the influence of acting forces. The Osteoarthritis (OA), is degenerative joint disease, caused by the breakdown of cartilage and is most common in hips. As OA is progressing the mechanical stress on joint increase, causing a degeneration and deformation of a femur head. Due to changes of mechanical conditions in the joint the structure of bone adapts to new loading forces. The purpose of the study is to determine the mechanical and structural properties of human femoral bone tissue in different stages of OA.

5

Hydrolizat kolagenu - nowoczesny suplement diety

Świderski F., Czerwonka M., Waszkiewicz-Robak B.

Przemysł Spożywczy

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2009

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T. 63, nr 4

42-44

PL

Kolagen stanowi ok. 30% wszystkich białek występujących w organizmie człowieka. Po dwudziestym piątym roku życia, w wyniku procesu starzenia, poziom kolagenu jest coraz mniejszy, co może powodować wiele schorzeń kości i stawów. Suplementy diety zawierające hydrolizat kolagenu stymulują syntezę kolagenu w stawach i kościach. Badania wykazały, że suplement ten jest pomocny w leczeniu osteoartrozy i osteoporozy.

EN

Collagen accounts for about 30% of human body's total protein and is essential for the healthy growth and development of muscles, tendons and bones. From the age of 25 our collagen levels is subject to reduction as a part of ageing process, what could contribute to many bone and joint diseases. Nutritional supplements containing hydrolyzed collagen could stimulate collagen synthesis in joints and bones. The conducted tudies showed that this supplement was helpful in prevention and treating osteoarthritis and osteoporosis.