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PubMed1993

Characteristics of anti-type II collagen antibody binding to articular cartilage.

OBJECTIVE: Previous studies suggested that it was possible to characterize the intact surface of articular cartilage by probing it with antibodies against matrix macromolecules. The present studies were undertaken to investigate type II collagen (CII) epitope availability on the intact surface of articular cartilage. METHODS: Normal bovine, rabbit, and human cartilage specimens were used to measure binding of anti-CII antibodies to the articular and cut surfaces of cartilage. Antisera were raised against the material obtained after brief extraction of the cartilage surface with 4M guanidine solution. RESULTS: Anti-CII did not bind to the intact surface of rabbit articular cartilage when compared with control rat sera, but did bind significantly to the cut surface. With normal human articular cartilage, the cut surfaces bound approximately 4 times as much anti-CII antibody as the intact articular surfaces. These findings suggested that the CII epitopes are normally protected by the superficial cartilage layer. In experiments carried out to characterize this layer, binding of anti-CII antibodies was unchanged after exhaustive washing of bovine or rabbit cartilage with phosphate buffered saline or 1M NaCl solution, whereas it was significantly increased after brief exposure to 4M guanidine solution or after incubation with neutrophil elastase. No restoration of the protection of CII epitopes in guanidine-treated cartilage could be achieved by incubation with undiluted normal bovine synovial fluid; however, 8-day culture of elastase-treated cartilage explants resulted in partial restoration of protection of the CII epitopes. Rat and rabbit antisera raised against the cartilage surface material extracted with 4M guanidine contained antibodies that bound to the cartilage surface. By Western blotting, rat antibodies identified 50-65-kd protein bands present in the guanidine extract, but not present either in the material obtained from brief digestion of cartilage with neutrophil elastase or in synovial fluid. The rabbit antisera identified a broad 70-95-kd band. Exposure of elastase-treated cartilage to the guanidine-extracted material resulted in a partial decrease of anti-CII antibody binding. CONCLUSION: These results suggest that CII on intact cartilage is protected from antibody binding, and that the protective material is at least partly proteinaceous in nature, is unlikely to be derived from synovial fluid, is noncovalently bound to the underlying intercellular matrix, and is synthesized by resident chondrocytes. Further characterization of the protective material may provide important information on the mechanisms of early cartilage damage in inflammatory arthritis.

Animals↗
PubMed1997

Stimulation of proteoglycan synthesis in explants of porcine articular cartilage by recombinant osteogenic protein-1 (bone morphogenetic protein-7).

UNLABELLED: Osteogenic protein-1 (also known as bone morphogenetic protein-7) is a member of the bone morphogenetic protein family. Bone morphogenetic proteins and related members of the TGF-beta (transforming growth factor-beta) superfamily are involved in the development and repair of bone. Recombinant bone morphogenetic proteins induce the formation of new cartilage and bone at heterotopic sites. We investigated the influence of recombinant osteogenic protein-1 (at doses of three, ten, thirty, or 100 nanograms per milliliter) on the synthesis and release of proteoglycans and the maintenance of a steady-state concentration of proteoglycans in explants of porcine articular cartilage that were maintained in chemically defined serum-free medium. We found a dose-dependent stimulation of proteoglycan synthesis and a concurrent decrease in the rate of release of proteoglycans from the explants. The size of the proteoglycan monomers and the composition of the glycosaminoglycan chains in the untreated articular cartilage were similar to those in the articular cartilage treated with osteogenic protein-1. The capacity of the newly synthesized proteoglycan monomers to form aggregates with exogenous hyaluronic acid was found to be similar to that of proteoglycans in bovine nasal cartilage. Our results demonstrated that osteogenic protein-1 stimulated the synthesis of proteoglycans and diminished the release of proteoglycans from explants of porcine articular cartilage. CLINICAL RELEVANCE: The maintenance and repair of articular cartilage is a formidable challenge in clinical orthopaedics. The stimulation of proteoglycan synthesis by osteogenic protein-1 (bone morphogenetic protein-7) in explants of cartilage maintained in chemically defined serum-free medium implies that recombinant osteogenic protein-1 may play a role in the maintenance of a steady-state concentration of proteoglycans in articular cartilage, a desirable prerequisite for optimum repair of cartilage. Osteogenic protein-1 can initiate the formation of cartilage from mesenchymal cells. Once new cartilage has formed at the site of repair, osteogenic protein-1 also may maintain the synthesis of proteoglycans.

Animals↗
PubMed2001

Inactivation of one allele of the type II collagen gene alters the collagen network in murine articular cartilage and makes cartilage softer.

OBJECTIVE: To evaluate the influence of inactivation of one allele ("heterozygous knockout" or "heterozygous inactivation") of the type II procollagen gene (Col2a1) on the biomechanical properties and structure of the articular cartilage and subchondral bone in 15 month old mice. METHODS: Indentation stiffness of the humerus head articular cartilage was measured by a microindentation method. Cartilage and subchondral bone were prepared for digital densitometry of proteoglycans (PGs), polarised light microscopy (PLM) of collagen, and osteoarthrosis (OA) grading. RESULTS: Heterozygous inactivation of the Col2a1 gene softened articular cartilage (p=0.002) as measured by indentation stiffness ((mean (SEM) 0.50 (0.07) MPa v 0.94 (0.13) MPa in controls). Fibrillar collagen network exhibited lower birefringence in the intermediate (p=0.04) and deep zones (p=0.01) of cartilage by PLM, indicating either decreased collagen content or a lower degree of fibril parallelism in the knockout mice. The total and zonal thicknesses of articular cartilage were unchanged. Zonal PG contents did not differ significantly. In knockout mice, the prevalence of superficial fibrillation-that is, a sign of OA, was higher than in controls (73% v 21%, p=0.002). The collagen induced birefringence of the superficial zone was not reduced. The subchondral bone volume fraction was lower in knockout mice than in controls, 31% v 43% (p=0.01), and optical retardation values in PLM of bone collagen were slightly but significantly lower (p=0.01). CONCLUSION: Heterozygous inactivation of the Col2a1 gene made articular cartilage softer, altered the collagenous network, reduced subchondral bone volume, and altered its microstructure. Changes in the cartilage collagen network probably contributed to increased susceptibility to OA.

Animals↗
PubMed2000

Topographical mapping of biochemical properties of articular cartilage in the equine fetlock joint.

The aim of this study was to evaluate topographical differences in the biochemical composition of the extracellular matrix of articular cartilage of the normal equine fetlock joint. Water content, DNA content, glycosaminoglycan (GAG) content and a number of characteristics of the collagen network (total collagen content, levels of hydroxylysine- (Hyl) and the crosslink hydroxylysylpyridinoline, (HP) of articular cartilage in the proximal 1st phalanx (P1), distal 3rd metacarpal bone (MC), and proximal sesamoid bones (PSB) were determined in the left and right fetlock joint of 6 mature horses (age 5-9 years). Twenty-eight sites were sampled per joint, which included the clinically important areas often associated with pathology. Biochemical differences were evaluated between sampling sites and related with the predisposition for osteochondral injury and type of loading. Significant regional differences in the composition of the extracellular matrix existed within the joint. Furthermore, left and right joints exhibited biochemical differences. Typical topographic distribution patterns were observed for each parameter. In P1 the dorsal and palmar articular margin showed a significantly lower GAG content than the more centrally located sites. Collagen content and HP crosslinks were higher at the joint margins than in the central area. Also, in the MC, GAG content was significantly lower at the (dorsal) articular margin compared with the central area. Consistent with findings in P1, collagen and HP crosslinks were significantly lower in the central area compared to the (dorsal) articular margin. Biochemical and biomechanical heterogeneity of articular cartilage is supposed to reflect the different functional demands made at different sites. In the present study, GAG content was highest in the constantly loaded central areas of the joint surfaces. In contrast, collagen content and HP crosslinks were higher in areas intermittently subjected to peak loading which suggests that the response to a certain type of loading of the various components of the extracellular matrix of articular cartilage are different. The differences in biochemical characteristics between the various sites may help to explain the site specificity of osteochondral lesions commonly found in the equine fetlock joint. Finally, these findings emphasise that the choice of sampling sites may profoundly influence the outcome of biochemical studies of articular cartilage.

Amino Acids↗
PubMed1986

Stimulation of proteoglycan biosynthesis by serum and insulin-like growth factor-I in cultured bovine articular cartilage.

The addition of foetal calf serum to explant cultures of adult bovine articular cartilage is known to stimulate proteoglycan synthesis in a dose-dependent manner. We have now shown the activity in serum responsible for this effect to be heat- and acid-stable, to be associated with a high-Mr complex in normal serum but converted to a low-Mr form under acid conditions. The activity has an apparent Mr approximately 10,000 and isoelectric points similar to those reported for insulin-like growth factors (IGFs). Addition of a monoclonal antibody against insulin-like growth factor-I (IGF-I) prevented foetal calf serum from stimulating proteoglycan synthesis. Physiological concentrations of recombinant IGF-I or pharmacological levels of insulin when added to cartilage cultures mimicked the proteoglycan-stimulatory activity of serum. IGF-I appeared to act by increasing the rate of proteoglycan synthesis and did not change the nature of the proteoglycan synthesized nor the rate of proteoglycan catabolism by the tissue, suggesting that IGF-I may be important in the regulation of proteoglycan metabolism in adult articular cartilage. Furthermore, IGF-I can replace foetal calf serum in the culture medium, thereby allowing the use of a fully-defined medium which will maintain the synthesis and tissue levels of proteoglycan in adult articular cartilage explants for up to 5 days.

Animals↗
PubMed1995

A study of the chemical composition of the proximal tibial articular cartilage and growth plate of broiler chickens.

This study was undertaken to analyze the chemical composition of the proximal tibial articular cartilage and growth plate from 1-mo-old broiler chickens. The composition was different between the two types of cartilage (weight-bearing tissue and the tissue of growth center). The dry matter and collagen contents and the ratio of keratan sulfate to sulfated glycosaminoglycan (GAG) were higher, and the total GAG uronic acid, chondroitin sulfate, hyaluronic acid, and sialic acid contents were lower in the articular cartilage hyaluronic acid, and sialic acid contents were lower in the articular cartilage than in the growth plate. Chondroitin sulfate was the major GAG, accounting for an average 96% of total GAG in both tissues. The size of chondroitin sulfate examined by gel chromatography was similar between the two tissues. The articular cartilage contained a small amount of dermatan sulfate (approximately 1% of total GAG) with low iduronic acid content (38% of total uronic acid). There was no appreciable amount of dermatan sulfate found in the growth plate. Proteoglycans were extracted from these tissues with 4 M-guanidine hydrochloride and separated by ion-exchange chromatography and gel chromatography. The uronic acid to protein ratio in the proteoglycan fraction was similar (average 2.6) between the two tissues. However, gel electrophoresis of chondroitinase-ABC digests of proteoglycan fraction showed differences in their composition.

Animals↗
PubMed2001

The role of flow-independent viscoelasticity in the biphasic tensile and compressive responses of articular cartilage.

A long-standing challenge in the biomechanics of connective tissues (e.g., articular cartilage, ligament, tendon) has been the reported disparities between their tensile and compressive properties. In general, the intrinsic tensile properties of the solid matrices of these tissues are dictated by the collagen content and microstructural architecture, and the intrinsic compressive properties are dictated by their proteoglycan content and molecular organization as well as water content. These distinct materials give rise to a pronounced and experimentally well-documented nonlinear tension-compression stress-strain responses, as well as biphasic or intrinsic extracellular matrix viscoelastic responses. While many constitutive models of articular cartilage have captured one or more of these experimental responses, no single constitutive law has successfully described the uniaxial tensile and compressive responses of cartilage within the same framework. The objective of this study was to combine two previously proposed extensions of the biphasic theory of Mow et al. [1980, ASME J. Biomech. Eng., 102, pp. 73-84] to incorporate tension-compression nonlinearity as well as intrinsic viscoelasticity of the solid matrix of cartilage. The biphasic-conewise linear elastic model proposed by Soltz and Ateshian [2000, ASME J. Biomech. Eng., 122, pp. 576-586] and based on the bimodular stress-strain constitutive law introduced by Curnier et al. [1995, J. Elasticity, 37, pp. 1-38], as well as the biphasic poroviscoelastic model of Mak [1986, ASME J. Biomech. Eng., 108, pp. 123-130], which employs the quasi-linear viscoelastic model of Fung [1981, Biomechanics: Mechanical Properties of Living Tissues, Springer-Verlag, New York], were combined in a single model to analyze the response of cartilage to standard testing configurations. Results were compared to experimental data from the literature and it was found that a simultaneous prediction of compression and tension experiments of articular cartilage, under stress-relaxation and dynamic loading, can be achieved when properly taking into account both flow-dependent and flow-independent viscoelasticity effects, as well as tension-compression nonlinearity.

Animals↗
PubMed2003

[The value of autologous osteochondral paste for in-vitro treatment of damage to articular cartilage. Part I. Macroscopic and microscopic assessment of the regenerated articular surface].

The limited ability of articular cartilage to regenerate after trauma has been the main reason for research of new repair techniques. The aim of this paper was to assess in in-vitro conditions the value of autologous osteochondral of pulp--macroscopic analysis of the regenerated articular surface and microscopic assessment of the dominant tissue in the regenerate. The experimental model consisted of a full-depth cartilage defect of the articular surface of the distal femur in rabbits. The animals were subdivided into 3 groups: group A--with defect with osteochondral of pulp, group B--with defects filled with osteochondral of pulp covered by periosteum, group C--defect untreated. After observation periods of 4, 8 and 12 weeks the regenerates were assessed using the Brittberg and O'Driscoll scale. In the overall macroscopic assessment group A prevailed because of the best defect filling. Microscopic assessment showed that in group A the defect had been filled with cartilage very similar to hyaline cartilage (hyaline--like cartilage). Basing on the result of the experiment, we assume that osteochondral of pulp has chondrogenic properties.

Animals↗
PubMed2004

Release of hyaluronan and hyaladherins (aggrecan G1 domain and link proteins) from articular cartilage exposed to ADAMTS-4 (aggrecanase 1) or ADAMTS-5 (aggrecanase 2).

OBJECTIVE: To determine whether aggrecanase (ADAMTS) activities in articular cartilage can directly lead to the release of hyaluronan (HA) and hyaladherins (aggrecan G1 domain and link proteins), as may occur ex vivo during stimulation of cartilage explants with interleukin-1 (IL-1) or retinoic acid or in vivo in synovial joints during aging and joint pathology. METHODS: Bovine articular cartilage discs (live or freeze-killed) were cultured in the presence of IL-1 or were incubated in digestion buffer containing recombinant human ADAMTS-4 (rHuADAMTS-4; aggrecanase 1) or rHuADAMTS-5 (aggrecanase 2). Culture media, digestion supernatants, and tissue extracts were assayed for sulfated glycosaminoglycan (sGAG) content and analyzed by Western blotting to detect aggrecanase-generated G1 domain (using neoepitope monoclonal antibody AGG-C1/anti-NITEGE(373)) and link proteins (using monoclonal antibody 8-A-4), as well as by quantitative enzyme-linked immunosorbent assays to detect aggrecanase-generated G1 domain (G1-NITEGE(373)) and HA. RESULTS: IL-1 treatment of live cartilage explants induced a time-dependent release of sGAG, aggrecanase-generated G1 domain (G1-NITEGE(373)), and HA into the culture media. Exposure of live or freeze-killed articular cartilage discs to rHuADAMTS-4 or rHuADAMTS-5 resulted in a dose- and time-dependent release of sGAG and hyaluronan from the tissue, accompanied by a concomitant release of functionally intact hyaladherins (aggrecan G1-NITEGE(373) and link proteins). CONCLUSION: Coincident with aggrecanolysis, aggrecanase activities in articular cartilage may actuate the release of HA and associated hyaladherins, thereby further compromising the integrity of the cartilage matrix during degenerative joint diseases such as osteoarthritis.

ADAM Proteins↗
PubMed2004

Chondrocyte viability and metabolic activity after treatment of bovine articular cartilage with bipolar radiofrequency: an in vitro study.

PURPOSE: Some controversy exists regarding the effects of radiofrequency (RF) probes on articular cartilage. To further elucidate these effects, we examined the chondrocyte viability and metabolic activity after treatment of fresh bovine articular cartilage with bipolar RF probes. TYPE OF STUDY: In vitro assessment. METHODS: Three fresh bovine knees served as a baseline control for chondrocyte viability, yielding 6 samples (1 from each medial femoral condyle and 1 from each lateral femoral condyle). After the baseline expected chondrocyte viability was determined, 3 additional bovine knees served as the experimental specimens for the study. Under sterile conditions, 2 different bipolar RF probes were used to treat the articular surface in a light contact mode, moving at a linear rate of 3 to 4 mm/s to provide tissue debridement. Full-thickness articular cartilage was then harvested from each of the treatment areas. Six samples per probe were then assessed for chondrocyte viability using fluorescent double-staining followed by confocal microscopy; 6 samples per probe were assessed for metabolic activity using an 35SO4 incorporation assay; and 12 additional untreated samples were obtained to serve as controls for viability (n = 6) and metabolic activity (n = 6). RESULTS: The depth of chondrocyte death (mean +/- standard deviation) was 109.4 +/- 22.1 microm after treatment with the ACD-50 probe, and was 172.3 +/- 34.3 microm after treatment with the 2.5-mm/90 degrees probe. The 35SO4 uptake (mean +/- standard deviation) was 2584 +/- 1388 cpm/mg dry cartilage for the ACD-50 probe and 1995 +/- 852 cpm/mg of dry cartilage for the 2.5-mm/90 degrees probe. The 35SO4 uptake for the control was 2647 +/- 1380 cpm/mg dry cartilage. CONCLUSIONS: The 2 probes tested created a well-controlled debridement with smooth edges and a defined margin of chondrocyte death that extended approximately 100 to 200 microm deep to the treatment area. There does not appear to be a significant effect on the metabolic activity of the chondrocytes adjacent to the treatment zone, but with the small sample size we lacked sufficient statistical power to definitively determine these effects. CLINICAL RELEVANCE: The 2 bipolar radiofrequency probes tested created a well-controlled debridement in normal articular cartilage with smooth edges and a defined margin of chondrocyte death that extended approximately 100 to 200 microm into the treatment area.

Animals↗
PubMed2006

Depth-dependent compressive equilibrium properties of articular cartilage explained by its composition.

For this study, we hypothesized that the depth-dependent compressive equilibrium properties of articular cartilage are the inherent consequence of its depth-dependent composition, and not the result of depth-dependent material properties. To test this hypothesis, our recently developed fibril-reinforced poroviscoelastic swelling model was expanded to include the influence of intra- and extra-fibrillar water content, and the influence of the solid fraction on the compressive properties of the tissue. With this model, the depth-dependent compressive equilibrium properties of articular cartilage were determined, and compared with experimental data from the literature. The typical depth-dependent behavior of articular cartilage was predicted by this model. The effective aggregate modulus was highly strain-dependent. It decreased with increasing strain for low strains, and increases with increasing strain for high strains. This effect was more pronounced with increasing distance from the articular surface. The main insight from this study is that the depth-dependent material behavior of articular cartilage can be obtained from its depth-dependent composition only. This eliminates the need for the assumption that the material properties of the different constituents themselves vary with depth. Such insights are important for understanding cartilage mechanical behavior, cartilage damage mechanisms and tissue engineering studies.

Cartilage, Articular↗
PubMed2002

Mechano-electrochemical properties of articular cartilage: their inhomogeneities and anisotropies.

In this chapter, the recent advances in cartilage biomechanics and electromechanics are reviewed and summarized. Our emphasis is on the new experimental techniques in cartilage mechanical testing, new experimental and theoretical findings in cartilage biomechanics and electromechanics, and emerging theories and computational modeling of articular cartilage. The charged nature and depth-dependent inhomogeneity in mechano-electrochemical properties of articular cartilage are examined, and their importance in the normal and/or pathological structure-function relationships with cartilage is discussed, along with their pathophysiological implications. Developments in theoretical and computational models of articular cartilage are summarized, and their application in cartilage biomechanics and biology is reviewed. Future directions in cartilage biomechanics and mechano-biology research are proposed.

Anisotropy↗
PubMed2005

Tissue engineering of articular cartilage using an allograft of cultured chondrocytes in a membrane-sealed atelocollagen honeycomb-shaped scaffold (ACHMS scaffold).

The aim of this study was to investigate with tissue engineering procedures the possibility of using atelocollagen honeycomb-shaped scaffolds sealed with a membrane (ACHMS scaffold) for the culturing of chondrocytes to repair articular cartilage defects. Chondrocytes from the articular cartilage of Japanese white rabbits were cultured in ACHMS scaffolds to allow a high-density, three-dimensional culturing for up to 21 days. Although the DNA content in the scaffold increased at a lower rate than monolayer culturing, scanning electron microscopy data showed that the scaffold was filled with grown chondrocytes and their produced extracellular matrix after 21 days. In addition, glycosaminoglycan (GAG) accumulation in the scaffold culture was at a higher level than the monolayer culture. Cultured cartilage in vitro for 14 days showed enough elasticity and stiffness to be handled in vivo. An articular cartilage defect was initiated in the patellar groove of the femur of rabbits and was subsequently filled with the chondrocyte-cultured ACHMS scaffold, ACHMS scaffold alone, or non-filled (control). Three months after the operations, histological analysis showed that only defects inserted with chondrocytes being cultured in ACHMS scaffolds were filled with reparative hyaline cartilage, and thereby highly expressing type II collagen. These results indicate that implantation of allogenic chondrocytes cultured in ACHMS scaffolds may be effective in repairing articular cartilage defects.

Animals↗
PubMed1993

[Measurement of collagen content in articular cartilage of normal Chinese].

We determine the collagen contents of fresh articular cartilage from 188 normal Chinese who died in accidents. Among them, the collagen content of femoral head cartilage (104 cases) was 496 +/- 35mg/g, femoral condyle cartilage (62) 456 +/- 38mg/g, and humeral head cartilage 588 +/- 42mg/g. The normal range of collagen contents in Chinese articular cartilage was defined for the pathological studies of collagen metabolic changes in cartilage. The collagen contents of the non-loading areas were evidently higher than those of the loading ones. The more pressure the cartilage beared, the less collagen contents it contained. In our experiment, the disturbances of "free" hydroxyproline were eliminated by analysing hydroxyproline with rehydrolysis after extraction with heated trichloroacetic acid.

Adolescent↗
PubMed2000

Simultaneous changes in the mechanical properties, quantitative collagen organization, and proteoglycan concentration of articular cartilage following canine meniscectomy.

The mechanical properties and microstructure of articular cartilage from the canine tibial plateau were studied 12 weeks after total medial meniscectomy. The organization of the birefringent collagen network was measured with quantitative polarized light microscopy to determine the thickness and the degree of organization of the superficial and deep zones. The zonal concentration of sulfated glycosaminoglycan was quantified with digital densitometry of safranin-O staining. Equilibrium compressive and shear properties, as well as dynamic shear properties, were measured at sites adjacent to those of microstructural analysis. The results evinced significant loss of cartilage function following meniscectomy, with decreases of 20-50% in the compressive and shear moduli. There was no evidence of alterations in the degree of collagen fibrillar organization, although a complete loss of the surface zone was seen in 60% of the samples that underwent meniscectomy. Meniscectomy resulted in a decreased concentration of sulfated glycosaminoglycan, and significant positive correlations were found between the equilibrium compressive modulus and the glycosaminoglycan content. Furthermore, the shear properties of cartilage correlated directly with collagen fibrillar organization measured at the superficial zone of corresponding sites. These findings demonstrate that meniscectomy leads to impaired mechanical function of articular cartilage, with significant evidence of quantitative correlations between cartilage microstructure and mechanics.

Animals↗
PubMed2006

Functional changes in articular cartilage after meniscal allograft transplantation: a quantitative histochemical evaluation in rabbits.

PURPOSE: To evaluate quantitatively functional changes in articular cartilage after immediate and delayed meniscus transplantation in rabbits. TYPE OF STUDY: Experimental study. METHODS: Thirty rabbits were divided into 5 groups: groups A and C were subjected to meniscectomy only, groups B and D underwent meniscal transplantation immediately after meniscectomy, and group E had delayed transplantation 6 weeks after meniscectomy. Six nonoperated knees served as controls. Functional changes in articular cartilage were examined at 6 weeks (groups A, B) and 1 year (groups C, D, E, controls) after surgery by measuring proteoglycan content of the extracellular matrix as a measure of its quality and lactate dehydrogenase (LDH) activity in chondrocytes as a measure of their vitality. RESULTS: At 6-week and 1-year follow-up, no significant differences were found between the immediate transplant group and postmeniscectomy group. The delayed transplant group showed a significantly decreased proteoglycan content compared with the postmeniscectomy group. No significant differences in cellular LDH activity were found between the immediate transplant group and postmeniscectomy group at 6 weeks and 1 year. However, the delayed transplant group showed a significant decrease in LDH activity compared with the postmeniscectomy group. CONCLUSIONS: Immediate meniscal transplantation in rabbits did not significantly reduce degenerative changes of articular cartilage in comparison with meniscectomy on a short-term and long-term basis, whereas delayed transplantation led to more degenerative changes than meniscectomy. CLINICAL RELEVANCE: Before meniscus transplantation can be considered as an alternative to meniscectomy in clinical practice, it has to be determined whether this procedure has any protective effect on articular cartilage on the long term.

Animals↗
PubMed1985

The effect of synovectomy on the articular cartilage of the knee joint in rabbits.

Subtotal synovectomy was performed on the right knee joints of 20 immature and 20 mature rabbits, and articular cartilage from the femoral and tibial condyles and the patellae was examined at 1, 3, 5 and 12 weeks after operation. Specimens from the unoperated left knees provided the controls. Each specimen was examined macroscopically and with histological (H-E stain) and histochemical (safranin-O stain) techniques for abnormalities in structure, cell population, stain intensity and distribution. The femoral articular cartilage was most affected by synovectomy. The tibial articular cartilage was only moderately affected and the patellar articular cartilage was even less affected. The histochemical changes were transient and reversible, being more severe and prolonged in the mature animals. No changes in either group were noted on gross inspection or in the H-E stained sections.

Animals↗
PubMed2003

Articular cartilage restoration with costal cartilage previously fused with bone.

A novel procedure was developed for restoration of an articular cartilage defect using an autologous costal cartilage prepared with iliac bone, and the durability in vivo of this biologic construct was examined. First, an osteochondral complex was prepared (successful preparation, 67 of 80). Cancellous bone blocks isolated from the ilium of male Japanese White rabbits aged 5 months were implanted onto the surface of the costal cartilage before being tied by a pair of 3-0 silk thread sutures that were looped around the costal cartilage from behind. Second, 3 months later, the bone-attached costal cartilage was harvested and implanted into a full-thickness cartilage defect induced in a trochlear groove of the femur. All of the grafts were fixed to the recipient, maintaining its cartilage structure until 6 months (n = 28) and 12 months (n = 12) after implantation. However, when the costal cartilage without any bony portion was implanted into a similarly induced defect, 42% (10 of 24) were detached from the recipient before 12 months after implantation. The nontreated defect did not heal spontaneously to a satisfactory level (n = 12). These findings suggest that an osteochondral fragment, prepared by grafting cancellous bone onto costal cartilage, can be used for articular cartilage restoration.

Animals↗