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PubMed1995

Differences in fatty acid composition of immature and mature articular cartilage in humans and sheep.

Chondrocytes are imbedded in an avascular, highly charged extracellular matrix which could form a barrier to the transfer of dietary essential fatty acids (EFA) to chondrocytes. A study was designed to assess the composition of immature and mature joint cartilage with respect to essential and nonessential fatty acids relevant to EFA deficiency. Cartilage and muscle samples were obtained from human fetus, infant and adult cadavers, and from fetal and mature sheep. Lipid extracts were prepared and the fatty acid composition determined. In human and sheep joint cartilage, linoleic acid (LA; 18:2n-6) content was lower, and n-9 eicosatrienoic acid (ETrA; 20:3n-9) and arachidonic acid (AA; 20:4n-6) were higher in fetuses compared to mature subjects. An intermediate pattern was seen in infant cartilage. n-3 Fatty acids tended to be higher in fetal than in mature cartilage in humans and in sheep. In human muscle (and in other noncartilaginous comparison tissues), similar differences between fetuses and adults were seen in LA and AA, but not in ETrA. In fetal sheep muscle, very low LA, reduced AA and raised ETrA levels compared to mature sheep muscle were seen. However, although the pattern is characteristic of EFA deficiency, the abundance of n-6 EFA in liver and spleen of human fetuses and of n-3 EFA in liver and spleen of fetal sheep suggests that placental transfer of EFA is not likely to be limiting. During fetal development, the metabolism of fatty acids is distinctive and differs between the species. ETrA appears to be a readily measurable component of some tissues at certain stages of development when its presence in tissues does not indicate EFA deficiency.

8,11,14-Eicosatrienoic Acid↗
PubMed1999

[Transplantation of chondrogenic tissue in the treatment of lesions of of the articular cartilage].

The problem in the treatment of deep hyalin cartilage defects is due to the minimal regeneration potential of this specific tissue. Several attempts were made to solve this difficulties experimentally and clinically. The proliferative potential of autogenous perichondrium/periost is well-known for decades. Perichondrium can be harvested from the lower ribs near to the sternum and periost from the adjacent bone (mostly proximal tibia). Experimentally and clinically, it has been shown that both types of tissue bear the potential to form hyalin-like cartilage under in vitro and in vivo conditions. Furthermore, regarding the biomechanical data (shear modulus) and the biochemical data (content of type II collagen) the newly grown tissue resembles normal hyalin cartilage. In addition, it has been shown that the transplant fixation with fibrin glue is sufficient in order to allow early postoperative treatment with continuous passive motion which is known to stimulate cartilaginuous regeneration. Despite the satisfying experimental and clinical results further examinations are needed in order to evaluate the optimal surgical technique and postoperative regimen regarding the CPM-criteria. In addition, application of growth-factor might further improve this biological kind of treatment which has to be analysed.

Animals↗
PubMed2004

Ultrasonography and articular cartilage defects in the knee: an in vitro evaluation of the accuracy of cartilage thickness and defect size assessment.

The purpose of this cadaver study was to test the accuracy of ultrasonography in measuring cartilage thickness, and the extent and depth of induced cartilage defects on the medial and lateral femoral condyles of the knee in a clinically relevant setting. With the knees maximally flexed, cartilage thickness was measured at 24 marked sites in four knees with a 10 MHz probe. The areas of measurement were then excised and the thickness measured with a calliper gauge. In another seven cadaver knees, 21 cartilage defects were produced. The defect diameter varied from 4 to 8 mm. The depths of the defects were either a partial cartilage defect (grade 2), a defect to intact subchondral bone (grade 3), or a defect involving subchondral bone (grade 4) (classification by ICRS). The limits of agreement between ultrasonography and calliper gauge measurement for cartilage thickness were chi(diff)+/-2SD(diff)=0.0+/-0.4 mm. For cartilage defect diameter, the limits of agreement between ultrasonography and the slide ruler measurement were chi(diff)+/-2SD(diff)=-0.2+/-1.0 mm. For the depths of the lesions there was a 100% agreement between radiologist and actual lesion depth for the classification into International Cartilage Repair Society (ICRS) grades 2, 3, and 4. Our conclusion is that ultrasonography is capable of measuring accurately both cartilage thickness and the extent and depth of induced cartilage defects in a cadaver model.

Aged↗
PubMed1996

MR imaging of articular cartilage in the ankle: comparison of available imaging sequences and methods of measurement in cadavers.

OBJECTIVE: To assess hyaline cartilage of cadaveric ankles using different magnetic resonance (MR) imaging techniques and various methods of measurement. DESIGN AND PATIENTS: Cartilage thicknesses of the talus and tibia were measured in ten cadaveric ankles by naked eye and by digitized image analysis from MR images of fat-suppressed T1-weighted gradient recalled (FS-SPGR), sequences and pulsed transfer saturation sequences with (FS-STS) and without fat-suppression (STS); these measurements were compared with those derived from direct inspection of cadaveric sections. The accuracy and precision errors were evaluated statistically for each imaging technique as well as measuring method. Contrast-to-noise ratios of cartilage versus joint fluid and marrow were compared for each of the imaging sequences. RESULTS: Statistically, measurements from FS-SPGR images were associated with the smallest estimation error. Precision error of measurements derived from digitized image analysis was found to be smaller than that derived from naked eye measurements. Cartilage thickness measurements in images from STS and FS-STS sequences revealed larger errors in both accuracy and precision. Inter-observer variance was larger in naked eye assessment of the cartilage. Contrast-to-noise ratio of cartilage versus joint fluid and marrow was higher with FS-SPGR than with FS-STS or STS sequences. CONCLUSION: Of the sequences and measurement techniques studied, the FS-SPGR sequence combined with the use of digitized image analysis provides the most accurate method for the assessment of ankle hyaline cartilage.

Aged↗
PubMed1996

Progressive degeneration of articular cartilage and intervertebral discs. An experimental study in transgenic mice bearing a type IX collagen mutation.

Transgenic mice expressing mutant alpha 1(IX) collagen were produced and found to develop progressive joint degeneration with age, as well as accelerated intervertebral disc degeneration. Radiological and histological studies showed that cervical and lumbar disc degeneration was more advanced in the transgenic mice than in control litter-mates. The changes included shrinkage or disappearance of the nucleus pulposus, and fissures in the annulus fibrosus which sometimes lead to herniation of disc material and slight osteophyte formation. These findings suggest that mutations of the type IX collagen may cause certain forms of degenerative disease in the spine as well as in joints.

Animals↗
PubMed2003

Ultrastructural MR imaging techniques of the knee articular cartilage: problems for routine clinical application.

The high incidence of cartilage lesions together with new surgical treatment techniques have necessitated the development of noninvasive cartilage evaluation techniques. Although arthroscopy has been the standard for cartilage evaluation, MR imaging has emerged as the imaging method of choice, allowing morphological evaluation of cartilage and cartilage repair tissue, as well as evaluation of its biochemical content. This article deals with current ultrastructural MR imaging techniques for cartilage evaluation, indicating the advantages as well as the drawbacks for routine clinical application.

Anisotropy↗
PubMed2000

Short-TE projection reconstruction MR microscopy in the evaluation of articular cartilage thickness.

The aim of this study was to assess the potential of projection-reconstruction (PR) MR microscopy in the accurate measurement of cartilage thickness. Short-TE PR microimages were acquired at 7.05 T on bone-cartilage cylindrical plugs excised from four regions of two disarticulated femoral heads (i. e. superior, inferior, posterior and anterior), using an NMR instrument equipped with a microimaging accessory. The PR microimages were then correlated with conventional spin-echo (SE) microimages and with histology. On PR microimages, acquired with an echo time of 3.2 ms, the cartilage signal was increased, allowing an accurate delineation of the cartilage from the tidemark/cortical bone region. As a consequence, by the PR method a more precise measurement of cartilage thickness compared with that performed by the conventional SE approach was feasible. An excellent correlation between PR microimages and histology was also obtained (r = 0.90). By the proposed method it is possible to accurately determine the cartilage thickness better than with the conventional SE sequences.

Aged↗
PubMed2001

Magnetic resonance imaging of articular cartilage.

Recent advances in treatments of the cartilage abnormalities require more information on the extent and shape of cartilage abnormalities and need for early detection of the lesions. In this article we review MR appearance of the cartilage correlated with histology, MR-related artifacts for cartilage imaging, conventional and dedicated MR techniques suitable for the cartilage, and their clinical utilization.

Cartilage, Articular↗
PubMed1999

The effects of NSAID on the matrix of human articular cartilages.

The present paper presents data obtained over a 12 year period, on the matrix synthesis and turnover in some 650 arthritic and 180 non-arthritic (N) human cartilages using a standardised in vitro method. When the relative metabolic (synthetic/repair activity) of these human cartilages was compared, it was demonstrated that in osteoarthritis (OA) and rheumatoid arthritis (RA) cartilages synthetic activity was diminished by approximately 50% as compared with N cartilages. However, the turnover rate of matrix was not significantly different between Non-arthritic and OA, but was very substantially increased in RA cartilages compatible with the activity of inflammatory cells and proteolytic enzymes released from pannus. The action of 13 NSAIDs was compared in terms of their effect on cartilage GAG synthesis. 3 of these NSAIDs were also studied in terms of their effect on cartilage collagen synthesis. Consideration of the results in this study and from published material, led to the suggestion that NSAIDs may be divided into 3 categories in respect of their in vitro action on the extracellular matrix of human arthritic cartilages: 1. Those such as Aceclofenac, Tenidap and Tolmetin which can stimulate matrix synthesis 2. Those such as Piroxicam, Tiaprofenic Acid and Aspirin which appear to be without significant effect on matrix synthesis and, 3. Those like Naproxen, Ibuprofen, Indomethacin, Nimezulide which significantly inhibit matrix synthesis. It is suggested that the stimulatory action of group 1 NSAID is due to inhibition of locally produced IL1 and consequent expression of growth factor activity. Other NSAIDs may also inhibit IL1 synthesis or release, but probably do not have a beneficial effect on chondrocyte synthetic activity as they have toxic effects on cartilage metabolism. These experiments led to the suggestion that NSAIDs such as Aceclofenac would be appropriate for long-term treatment of arthritic conditions provided that one is prepared to extrapolate between in vitro experiments on human cartilage and what may be happening in vivo.

Adult↗
PubMed2006

Repair of articular cartilage lesions in aged chickens by allogeneic transplantation of fresh embryonic epiphyses.

INTRODUCTION: The potential of fresh whole chick epiphyses of embryonic origin to serve as implant material for cartilage defects of aged chicken was tested. MATERIALS AND METHODS: Fresh epiphyses of 11-day-old embryos were collected from 24 animals and transplanted into defects created in the weight-bearing areas of tibiotarsal joint cartilage of 2-year-old chicks. Upon sacrifice, samples were examined macroscopically and microsections were prepared for histology. RESULTS: Macroscopically, control defects remained empty at all the time intervals. Defects of the experimental group were, on the other hand, filled with cartilaginous tissue as early as 2 weeks posttransplantation, although individual epiphyses could still be noted in the implant tissue. At 4 weeks and later, defects were filled with cartilaginous material indistinguishable from hyaline cartilage. Histologically, all grafts remained within the defect's pits, showing mitotic and metabolic activity typical to proliferating hyaline cartilage. The engrafted epiphyses showed a partial incorporation and integration with the surrounding host tissues already at 2 weeks. At 4 weeks and later, the integration was complete. CONCLUSIONS: It is concluded that a chick embryonic epiphyseal cartilage is suitable as a graft source for articular cartilage transplantation. The embryonic epiphyses provide immediate inherent stability to the graft and supply a good mix of mesenchymal progenitor cells responsible for the high rate of cell proliferation and adhesion to the differentiated committed chondrocytes of the host that create the typical favorable chondrogenic milieu. Based on the present findings, it is postulated that human embryonic epiphyses may, in the future, represent an alternative source to the commonly used techniques of hyaline cartilage repair.

Animals↗
PubMed2001

Determination of optimal transport conditions for biopsies of human articular cartilage as well as for suspensions of cultured chondrocytes used in autologous transplantation.

Autologous transplantation of chondrocytes is currently being promoted as a novel approach for the treatment of deep cartilage lesions. Briefly, the method involves enzyme-mediated release of chondrocytes from cartilage biopsies, the expansion of cells by in vitro cultivation and their re-implantation into the defect. The success of this technique depends on many factors including transport conditions for both, cartilage biopsies from the operating hall to the laboratory and the return transport of final suspension of cultured chondrocytes. To determine the extent of cellular damage in biopsies, chondrocytes were enzymatically isolated following a few days of tissue preservation in different tissue culture media. The proportion of dead cells was assessed by Trypan blue staining and counting. The viability was not dependant of the type of the medium used and remained approximately 50% in all samples, even after 72 h. To develop optimal conditions for transport of final chondrocyte suspension, isolated cells were firstly grown in monolayer cultures. Cell suspensions in media with different additives were injected into special glass containers used for the transport and left at 4 degrees C or 25 degrees C for up to 3 days. During this period every 24 h the samples were taken and viability as well as apoptosis levels were assessed. Viability of cells in suspensions at 25 degrees C decreased significantly and became inadequate already after 48 h. In contrast to that, the proportion of viable cells at 4 degrees C remained above 80% even after 48 h. In the majority of the samples, culture medium containing serum and vitamin C provided the best conditions for long-term preservation of chondrocytes.

Apoptosis↗