Modified Mankin Score Research Articles

Protective Effect of Normal Synovium on Damaged Cartilage

Objectives:Traumatic joint injury results in an acute inflammatory response. If uncontrolled, this can progress to chronic inflammation, which can expedite the onset of post-traumatic osteoarthritis (PTOA). Normal synovium plays an important protective role for cartilage, while inflamed synovium can lead to degenerative changes. Previous studies have investigated the cartilage-synovium in limited conditions, but the effect of normal synovium on damaged cartilage remains unknown. The purpose of this study is to investigate the effect of normal synovium on two types of damaged cartilage: IL-1β or impaction-induced.Methods:Fresh human tali and distal femoral condyles were obtained from 7 human donors (mean age; 39 years-old, 4 male and 3 female) with no history of joint disease. Gross morphology was assessed using Collins grading 0-4 and only normal joints of grade 0-1 were used. Two damage models were introduced: 1) treatment with IL-1β (10ng/ml) at 48 hours before co-culture; or 2) controlled mechanical impaction (600 N within 2 ms). Cartilage explants (8mm) and grossly normal synovium (8 mm) from both joints were harvested and randomized to one of six treatment groups (n = 5 in each group): non-treated cartilage without or with synovium (Group 1 or 2), IL-1β-treated cartilage without or with synovium (Group 3 or 4), impacted cartilage without or with synovium (Group 5 or 6). Samples were collected at 0, 2, and 14 days and assessed for the percentage of live cells and histology with Safranin O staining. Cell survival was measured using calcein AM and ethidium bromide homodimer-1. Image analysis was performed on the superficial and middle/deep zone. Live cells were counted using Image J. Histological grading was based on modified Mankin score. The level of significance for all analysis was set at P < .05.Results:The percentage of live cells in Group 1 was mostly unchanged, 79.9 - 87.9% in the superficial layer and >90% in the middle/deep layer with no significant differences between Group 1 and 2 (Figure 1). All damaged cartilage displayed elevated cell death, especially in the superficial layer at all time points (Group 3; 56.4 ± 20.0%, 44.5 ± 11.5%, and 57.6 ± 16.3%, Group 5; 14.8 ± 5.3, 12.8 ± 13.2%, and 20.1 ± 4.1%, respectively). In the presence of synovium, chondrocyte survival significantly increased at 2 and 14 days (Group 4; 75.3 ± 4.7% and 77.8 ± 7.8%, P < 0.01 and 0.02, Group 6; 31.8 ± 13.7% and 33.4 ± 14.3%, P = 0.03 and 0.04, respectively). By contrast, the percentage of cells in the middle/deep layer remained unchanged for both damaged cartilage with or without synovium. For histological analysis, non-treated cartilage (Group 1 and 2) had a normal structure through 14 days. Mankin score progressively increased in damaged cartilage (Group 3; 1.0 ± 1.41, 2.2 ± 1.8, and 3.25 ± 1.64, Group 5; 3.0 ± 1.2, 3.6 ± 1.1, and 4.6 ± 0.5 at 0, 2, and 14 days). In the presence of synovium, Mankin score decreased at 2 and 14 days (Group 4; 0.8 ± 1.3, and 0.8 ± 0.8, P = 0.087 and < 0.01, Group 6; 1.0 ± 0.0 and 1.6 ± 0.5, P =0.02 and < 0.01, respectively).Conclusion:These results demonstrate that healthy synovium is protective of damaged cartilage as evidenced by increased cell viability, especially in the superficial layer. These findings suggested that the inhibition of inflammation by normal synovium may lead to both the recovery of damaged cartilage and prevention of PTOA. In the future, the underlying mechanism responsible for the interaction between the normal synovium and damaged cartilage needs to be addressed.

Establishment of novel meniscal scaffold structures using polyglycolic and poly-l-lactic acids.

The purpose of this study was to evaluate various types of meniscus scaffolds that mimic the meniscus structure, and to establish a novel cell-free meniscus scaffold with polyglycolic acid or poly-l-lactic acid. Four types of scaffolds were implanted into Japanese white rabbits: poly-l-lactic acid sponge poly-l-lactic acid, PGA-coated PLLA sponge, PGA lamination, and film-coated PGA lamination. Samples were harvested at 8 and 12 weeks after implantation, and a compression stress test was performed. The meniscus size and Ishida scores were evaluated for regenerated tissue. Immunohistochemistry was analyzed by anti-type I, II and X collagen antibodies to investigate the structure of the regenerated tissue, and by anti-iNOS antibody to investigate the inflammatory tissue of the meniscus. The cell nuclei of lymphocytes and foreign body multinucleated giant cells were counted in hematoxylin and eosin staining. Modified Mankin scores for cartilage degeneration were used for assessment after Safranin-O/Fast Green staining. The biomechanical test showed that l- and film-coated PGA lamination exhibited greater strength than s- and PGA-coated PLLA sponge. At 12 weeks, the size of meniscus and the Ishida score in implanted film-coated PGA lamination were improved significantly compared with the defect groups. The type II collagen staining intensity in the PGA lamination lamination is significantly higher than the defect at eight weeks. The staining intensity of iNOS and number of lymphocytes significantly increased in sponge poly-l-lactic acid at eight weeks, and increased in p-PLLA at 12 weeks. Foreign body multinucleated giant cells in implantation groups appeared, especially at eight weeks. The Mankin score for film-coated PGA lamination was significantly lower than for the defect at 12 weeks. Novel meniscal scaffolds especially PGA should possess not only biological but also biomechanical functions. In conclusions, film-coated PGA lamination was the beneficial property for meniscus scaffold from the points of better biomechanical function, good regeneration, and less inflammation with chondroprotective effects.

Efficacy of extracorporeal shockwave therapy and low-intensity pulsed ultrasound in a rat knee osteoarthritis model: A randomized controlled trial.

This study aims to assess the efficacy of extracorporeal shockwave therapy (ESWT) and low-intensity pulsed ultrasound (LIPUS) on osteoarthritic rat knees. Twenty-four rats were divided into 3 groups: group 1-control (n=8), group 2-LIPUS (n=8) and group 3-ESWT (n=8). Cartilage degeneration was provided using mono-iodo-asetate (MIA). One milligram of MIA was delivered to the right knees in group 1 and both knees in group 2 and 3. A 0.09% saline solution was delivered to the left knees in group 1 for control. Twenty-four hours after the delivery, ESWT was applied once on the right knees in the group 2 rats to the medial tibia plateu with a 1 Hz frequency and 800 impulses. LIPUS was applied to the right knees in the group 2 rats to the medial tibia plateu with a 3 mHz frequency and 40 mW/cm2 intensity for 20 minutes over a period of 15 days. Pain scores were measured with a knee bend test. Bone mineral density measurements and scintigraphic bone scans were performed. Histopathological examination was done using a modified Mankin scale. There was no difference among the right knee subchondral bone osteoblastic activities (p>0.05). The left knee osteoblastic activities in the LIPUS and extracorporeal shockwave therapy (ESWT) groups were higher than those in the control group (p<0.05), but there was no difference between the LIPUS and ESWT groups. There was no difference among the groups for both knee subchondral bone BMD values (p>0.05). The modified Mankin scores of both the right and left knees of the ESWT and LIPUS groups were lower than those of the control group (p<0.05), but there was no difference between the ESWT and LIPUS groups. The pain scores of both knees of the ESWT and LIPUS groups at day 7 were higher than those of the control group (p<0.05), but there was no difference between the ESWT and LIPUS groups. There was no difference among the pain scores of the right knees at day 14 (p<0.05). ESWT and LIPUS have systemic proliferative and regenerative effects on cartilage and tissue.

Expression of Notch signaling pathway during osteoarthritis in the temporomandibular joint

PurposeOur study aim was to characterize the expression of Notch molecules during temporomandibular joint osteoarthritis (TMJOA), thus exploring the mechanism and roles that Notch signaling possibly plays in the initiation and progression of TMJOA. Materials and methodsA total of 126 mice were divided randomly into experimental groups, a sham-surgery group and a normal control group. In the experimental group, total discectomy was performed in the right temporomandibular joint (TMJ) to induce TMJOA; the sham-operation group underwent the same procedure without disc removal, and the normal control group was left undisturbed. Fourteen mice in each group were sacrificed in batches respectively at 1, 2, and 4 weeks postoperatively. Histology was performed to examine TMJOA in eight condyles each group, and a modified Mankin scoring system was used for evaluation. Immunohistochemistry was carried out to characterize the expression of the Notch markers Notch1, Jagged1, Hes1, and Hes5. Real-time polymerase chain reaction (RT-PCR) was performed for further detection and analysis of Notch markers in six condyles in each group. ResultsNotch1, Jagged1, and Hes5 were activated in the experimental group, with expression levels that increased dramatically over time, whereas the control group showed no fluctuation. Hes1 expression was suppressed at the beginning but was up-regulated afterward. ConclusionsOur data suggest that Notch signaling is activated in TMJOA with a much more abundant expression in osteoarthritis cartilage.

Changes of articular cartilage and subchondral bone after extracorporeal shockwave therapy in osteoarthritis of the knee.

We assessed the pathological changes of articular cartilage and subchondral bone on different locations of the knee after extracorporeal shockwave therapy (ESWT) in early osteoarthritis (OA). Rat knees under OA model by anterior cruciate ligament transaction (ACLT) and medial meniscectomy (MM) to induce OA changes. Among ESWT groups, ESWT were applied to medial (M) femur (F) and tibia (T) condyles was better than medial tibia condyle, medial femur condyle as well as medial and lateral (L) tibia condyles in gross osteoarthritic areas (p<0.05), osteophyte formation and subchondral sclerotic bone (p<0.05). Using sectional cartilage area, modified Mankin scoring system as well as thickness of calcified and un-calcified cartilage analysis, the results showed that articular cartilage damage was ameliorated and T+F(M) group had the most protection as compared with other locations (p<0.05). Detectable cartilage surface damage and proteoglycan loss were measured and T+F(M) group showed the smallest lesion score among other groups (p<0.05). Micro-CT revealed significantly improved in subchondral bone repair in all ESWT groups compared to OA group (p<0.05). There were no significantly differences in bone remodeling after ESWT groups except F(M) group. In the immunohistochemical analysis, T+F(M) group significant reduced TUNEL activity, promoted cartilage proliferation by observation of PCNA marker and reduced vascular invasion through observation of CD31 marker for angiogenesis compared to OA group (P<0.001). Overall the data suggested that the order of the effective site of ESWT was T+F(M) ≧ T(M) > T(M+L) > F(M) in OA rat knees.

Adelmidrol, in combination with hyaluronic acid, displays increased anti-inflammatory and analgesic effects against monosodium iodoacetate-induced osteoarthritis in rats.

BackgroundOsteoarthritis (OA) is a degenerative joint disease produced by a cascade of events that can ultimately lead to joint damage. The aim of this study was to evaluate the effect of adelmidrol, a synthetic palmitoylethanolamide analogue, combined with hyaluronic acid on pain severity and modulation of the inflammatory response in a rat model of monosodium iodoacetate (MIA)-induced osteoarthritis.MethodsOA was induced by intra-articular injection of MIA in the knee joint. On day 21 post-MIA administration, the knee joint was analyzed. Rats subjected to OA were treated by intra-articular injection of adelmidrol in combination with sodium hyaluronate at different doses and time points after MIA induction. Limb nociception was assessed by the paw withdrawal latency and threshold measurement. Samples were examined macroscopically, histologically, and by immunohistochemistry.ResultsAt day 21 post-MIA injection, the MIA + solvent and MIA + 1.0% sodium hyaluronate groups showed irregularities and fibrillation in the surface layer, a decrease in blood cells and multilayering in transition and radial zones, no pannus formation, and modified Mankin scores significantly higher than sham knees. The combination of hyaluronic acid and adelmidrol dose-dependently (adelmidrol 0.6% + 1.0% sodium hyaluronate and adelmidrol 2% + 1.0% sodium hyaluronate) reduced the histological alterations induced by MIA. Moreover, degeneration of articular cartilage, mast cell infiltration, and pro-inflammatory cytokine and chemokine plasma levels were significantly downregulated by treatment with a combination of hyaluronic acid and adelmidrol at the above doses.ConclusionsOur results clearly demonstrate that the combination of hyaluronic acid and adelmidrol improves the signs of OA induced by MIA.

Resurfacing full thickness defects of focal cartilage in the knee with titanium alloy implant with ceramic coating: an experimental Study in sheep

Objective To investigate the efficacy of resurfacing full thickness defects of focal knee cartilage with a titanium alloy implant with ceramic surface coating in sheep. Methods Twelve male sheep were used in this experiment. Standardized defects of focal knee cartilage(7 mm in diameter and 2 mm in depth)were created in the medial femoral condyle at both knees in 9 sheep which were randomly assigned into 3 groups(n=6). In group A, titanium alloy implants with ceramic surface coating were inserted into the defects. In group B, the defects were treated with titanium alloy implants. In group C, the defects were left untreated. The 6 untreated knee joints in another 3 sheep served as a control group(group D). The animals were sacrificed at 6 months. X-ray examinations were performed immediately after operation and at 6 months. Surface roughness of the implants was measured before implantation and at 6 months. The knee joints were evaluated according to O ’ Driscoll score. The damage to opposing cartilage was evaluated according to Outer-bridge score and modified Mankin score. Micro-CT analysis and histological observation were used to assess stability of the implants and the cartilage surrounding the implants. Results At 6 months, the surface roughness value in group B(0. 178 ±0. 063)was significantly higher than in group A(0. 034 ±0. 006)(P 0. 05). Micro-CT scan and histological observation showed that all the implants were mechanically stable and new-born cartilage covered the surface of implants well in groups A and B. Conclusion Titanium alloy implants with ceramic surface coating may favor resurfacing full thickness defects of focal knee cartilage in sheep. Key words: Knee joint; Cartilage, articular; Prosthesis and implants; Titanium; Wounds and injuries

Electroacupuncture protects against articular cartilage erosion by inhibiting mitogen-activated protein kinases in a rat model of osteoarthritis.

The therapeutic effects of electroacupuncture (EA) on osteoarthritis (OA) are well documented; however, the precise mechanisms of action have not yet been fully elucidated. The present study aimed to investigate the effect of EA on cartilage in an experimental animal model of OA induced by anterior cruciate ligament transection (ACLT) and to examine for concomitant changes in the expression of mitogen-activated protein kinases (MAPKs) in the articular cartilage. Thirty-three-month-old male Sprague Dawley rats were randomly divided into the following three groups (n=10 each): sham operated group (Control group), ACLT without treatment (ACLT group), and ACLT with EA treatment (ACLT+EA group). One week after ACLT, rats in the ACLT+EA group received 12 weeks of EA treatment. Histological analysis and quantitative real-time PCR were used to investigate the effects of EA on cartilage morphology (quantified using modified Mankin scores) and expression of MAPKs (p38, c-Jun N-terminal kinase (c-Jun), and extracellular signal-regulated kinase (ERK)1), respectively. ACLT produced coarse cartilage surfaces, fibrous degeneration, and fissuring, all of which were suppressed by EA treatment. Although Mankin scores in the ACLT+EA group were significantly higher compared to the Control group (p<0.01), they were significantly lower than the (untreated) ACLT group (p<0.01). The increase in mRNA expression of p38, c-Jun, ERK1, and matrix metalloproteinase (MMP)-13 observed in cartilage after ACLT was significantly inhibited by EA. EA appears to prevent the degeneration of articular cartilage, at least partly through regulation of MMP-13 and inhibition of MAPKs in the cartilage of rats with ACLT-induced OA.

Case Series With Histopathologic and Radiographic Analyses Following Failure of Fresh Osteochondral Allografts of the Talus.

Fresh osteochondral allografting of the talus is one treatment option for large chondral defects. Following positive early term results, failure rates of up to 35% have been reported. A retrieval study was performed to characterize failed talar allografts. Failed fresh osteochondral allografts of the talus were retrieved on revision. Cases of deep infection were excluded. After tissue fixation, samples were decalcified, embedded, and stained with Safranin-O/Fast Green, osteocalcin, tumor necrosis factor alpha (TNF-α), CD4, CD8, and CD68. Slides were graded according to the modified Mankin scoring system or severity scale. Medical record review was performed. Eight allografts (7 patients) were retrieved from patients, following an average term of implantation of 31 months (range, 12-58). There were 3 types of allografts in this series (hemidome, n=5; segmental, n=2; bipolar, n=1). Reasons for transplantation were post-traumatic arthritis or osteonecrosis; reasons for revision were graft failure/collapse, nonunion, progressive arthritis, and/or pain. Prior to revision, all grafts exhibited collapse and subchondral lucencies. At the graft host interface, Safranin-O staining demonstrated substantial loss of sulfated glycosaminoglycans, Osteocalcin immunostaning was nearly absent, CD68 (indicating osteoclast activity) was predominantly exhibited, and CD4+ helper T cells as well as CD8+ cytotoxic T cells and NK cells-cell types commonly implicated in allogeneic organ transplant rejection-were found in high concentrations. TNF-α was present throughout the graft. A histopathologic analysis of 8 retrieved, failed talar allografts was performed. Graft failure appeared to be primarily biologic, with an extensive loss of viable cartilaginous and osseous tissue at the graft-host interface. This study provides the first evidence of a potential CD4+ and CD8+ lymphocyte-mediated failure mechanism in fresh osteochondral allografts that were revised following collapse. Level IV, case series.

Articulation of Native Cartilage Against Different Femoral Component Materials. Oxidized Zirconium Damages Cartilage Less Than Cobalt-Chrome

BackgroundOxidized zirconium (OxZr) is produced by thermally driven oxidization creating an oxidized surface with the properties of a ceramic at the top of the Zr metal substrate. OxZr is much harder and has a lower coefficient of friction than cobalt-chrome (CoCr), both leading to better wear characteristics. We evaluated and compared damage to the cartilage of porcine patella plugs, articulating against OxZr vs CoCr. Our hypothesis was that, owing to its better wear properties, OxZr would damage cartilage less than CoCr. If this is true, OxZr might be a better material for the femoral component during total knee arthroplasty if the patella is not resurfaced. MethodsTwenty-one plugs from porcine patellae were prepared and tested in a reciprocating pin-on-disk machine while lubricated with bovine serum and under a constant load. Three different configurations were tested: cartilage-cartilage as the control group, cartilage-OxZr, and cartilage-CoCr. Macroscopic appearance, cartilage thickness, and the modified Mankin score were evaluated after 400,000 wear cycles. ResultsThe control group showed statistically significant less damage than plugs articulating against both other materials. Cartilage plugs articulating against OxZr were statistically significantly less damaged than those articulating against CoCr. ConclusionAlthough replacing cartilage by an implant always leads to deterioration of the cartilage counterface, OxZr results in less damage than CoCr. The use of OxZr might thus be preferable to CoCr in case of total knee arthroplasty without patella resurfacing.

Effect of Glucosamine Sulfate on Osteoarthritis in the Cruciate-Deficient Canine Model of Osteoarthritis.

Objective Osteoarthritis (OA) is a major cause of musculoskeletal pain and disability worldwide. The investigation of disease-modifying treatment options for OA has become an important aspect of orthopedic care. To assess the effect of intra-articular and oral glucosamine sulfate (GS) versus placebo on osteoarthritis in a canine model. Materials In this randomized, placebo-controlled, double-blinded study, OA was induced by anterior cruciate ligament transection (ACLT) according to the Pond-Nuki model in 32 canines. All canines were allocated into 4 treatment subgroups with treatment administered for 8 weeks: GS (400 mg) intra-articular, placebo intra-articular, GS (200 mg/kg body weight) oral, and placebo oral. The contralateral nonoperated stifle (knee) served as control. After 8 weeks, the medial and lateral femoral condyles, the medial and lateral tibial plateau and patella were histologically examined and anatomic changes quantified by light microscopy using the modified Mankin score. Results After 8 weeks, mean Mankin score values significantly ( P < 0.002) decreased in the intra-articular GS group (8.1; range 7.9-8.8) compared with the intra-articular placebo group (13.9; range 11.6-15.9) and again significantly ( P < 0.002) in the oral GS group (12.1; range 9.9-12.7) compared with the oral placebo group (15.1; range 12.5-17.0). Mean Mankin score values were significantly ( P < 0.002) lower in the intra-articular GS group compared with the oral GS group. Conclusion Both, intra-articular and oral administered GS significantly reduced histological signs of OA in the Pond-Nuki model, with the intra-articular application being more effective compared to oral administration.

Genome-Wide DNA Methylation Study Identifies Significant Epigenomic Changes in Osteoarthritic Subchondral Bone and Similarity to Overlying Cartilage.

To perform a genome-wide DNA methylation study to identify differential DNA methylation patterns in subchondral bone underlying eroded and intact cartilage from patients with hip osteoarthritis (OA) and to compare these with DNA methylation patterns in overlying cartilage. Genome-wide DNA methylation profiling using Illumina HumanMethylation 450 arrays was performed on eroded and intact cartilage and subchondral bone from within the same joint of 12 patients undergoing hip arthroplasty. Genes with differentially methylated CpG sites were analyzed to identify shared pathways, upstream regulators, and overrepresented gene ontologies, and these patterns were compared with those of the overlying cartilage. Histopathology was graded by modified Mankin score and assessed for correlation with DNA methylation. We identified 7,316 differentially methylated CpG sites in subchondral bone underlying eroded cartilage, most of which (∼75%) were hypomethylated, and 1,397 sites in overlying eroded cartilage, 126 of which were shared. Samples clustered into 3 groups with distinct histopathologic scores. We observed differential DNA methylation of genes including the RNA interference-processing gene AGO2, the growth factor TGFB3, the OA suppressor NFATC1, and the epigenetic effector HDAC4. Among known susceptibility genes in OA, 32 were differentially methylated in subchondral bone, 8 were differentially methylated in cartilage, and 5 were shared. Upstream regulator analysis using differentially methylated genes in OA subchondral bone showed a strong transforming growth factor β1 signature (P = 1 × 10(-40) ) and a tumor necrosis factor family signature (P = 3.2 × 10(-28) ), among others. Our data suggest the presence of an epigenetic phenotype associated with eroded OA subchondral bone that is similar to that of overlying eroded OA cartilage.

Malocclusion model of temporomandibular joint osteoarthritis in mice with and without receptor for advanced glycation end products

ObjectiveThis study has two aims: 1. Validate a non-invasive malocclusion model of mouse temporomandibular joint (TMJ) osteoarthritis (OA) that we developed and 2. Confirm role of inflammation in TMJ OA by comparing the disease in the presence and absence of the receptor for advanced glycation end products (RAGE). DesignThe malocclusion procedure was performed on eight week old mice, either wild type (WT) or without RAGE. ResultsWe observed TMJ OA at two weeks post-misalignment/malocclusion. The modified Mankin score used for the semi-quantitative assessment of OA showed an overall significantly higher score in mice with malocclusion compared to control mice at all times points (2, 4, 6 and 8 weeks). Mice with malocclusion showed a decrease in body weight by the first week after misalignment but returned to normal weight for their ages during the following weeks. The RAGE knock out (KO) mice had statistically lower modified Mankin scores compared to WT mice of the same age. The RAGE KO mice had statistically lower levels of Mmp-13 and HtrA1 but higher Tgf-β1, as measured by immunohistochemistry, compared to WT mice at eight weeks post malocclusion. ConclusionsWe demonstrate an inexpensive, efficient, highly reproducible and non-invasive model of mouse TMJ OA. The mechanical nature of the malocclusion resembles the natural development of TMJ OA in humans, making this an ideal model in future studies that aim to elucidate the pathogenesis of the disease leading to the discovery of a treatment. The RAGE plays a role in mouse TMJ OA.

Drying of open animal joints in vivo subsequently causes cartilage degeneration.

ObjectivesDuring open orthopaedic surgery, joints may be exposed to air, potentially leading to cartilage drying and chondrocyte death, however, the long-term effects of joint drying in vivo are poorly understood. We used an animal model to investigate the subsequent effects of joint drying on cartilage and chondrocytes.MethodsThe patellar groove of anaesthetised rats was exposed (sham-operated), or exposed and then subjected to laminar airflow (0.25m/s; 60 minutes) before wounds were sutured and animals recovered. Animals were monitored for up to eight weeks and then sacrificed. Cartilage and chondrocyte properties were studied by histology and confocal microscopy, respectively.ResultsJoint drying caused extensive chondrocyte death within the superficial regions of cartilage. Histology of dried cartilage demonstrated a loss of surface integrity at four weeks, fibrillations at eight weeks, and an increased modified Mankin score (p < 0.001). Cartilage thickness increased (p < 0.001), whereas chondrocyte density decreased at four weeks (p < 0.001), but then increased towards sham-operated levels (p < 0.01) at eight weeks. By week eight, chondrocyte pairing/clustering and cell volume increased (p < 0.05; p < 0.001, respectively).ConclusionsThese in vivo results demonstrated for the first time that as a result of laminar airflow, cartilage degeneration occurred which has characteristics similar to those seen in early osteoarthritis. Maintenance of adequate cartilage hydration during open orthopaedic surgery is therefore of paramount importance.Cite this article: Dr A. Hall. Drying of open animal joints in vivo subsequently causes cartilage degeneration. Bone Joint Res 2016;5:137–144. DOI: 10.1302/2046-3758.54.2000594.

The role of TGF-ß1 in osteoarthritis of the temporomandibular joint in two genetic mouse models

ObjectiveThe objective of this study is to elucidate osteoarthritis (OA) progression in the temporomandibular joint (TMJ) in two genetic mouse models by assessing the expression of an identified inflammatory marker associated with OA, viz., Tgf-ß1. This study provides mechanistic insight into disease progression based on the temporal expression of Tgf-ß1 in the TMJ. DesignThe two models included the heterozygous chondrodysplasia mutation (cho/+), a Coll11a1 mutation, and the autosomal semidominant disproportionate micromelia mutation (Dmm/+), a Col2a1 mutation. To determine OA status histologically, TMJs from each mutant were fixed, sectioned and stained with Safranin O to identify proteoglycans in condylar cartilage and counterstained with Fast Green. The extent of staining and onset of OA-like changes were quantified using the Modified Mankin scoring system. Using immunofluorescence, selected tissue sections of each genotype were stained for the presence of Tgf-ß1, HtrA1, and p-Smad2. ResultsThe results revealed Mankin scores of the condylar cartilage of both mutants that are consistent with established histopathological changes of OA. Immunofluorescence indicated increased expression of all three molecular markers and their co-localization within condylar chondrocytes of both mutants. ConclusionsElevated Tgf-ß1 expression in mutant condylar cartilage supports the hypothesis that this inflammatory mediator is mechanistically involved in the pathogenesis of TMJ OA. Compared to basal expression in control TMJs, the positive co-localized staining for Tgf-ß1, HtrA1, and p-Smad2 in both mutants demonstrates involvement of these molecules in the degradative pathway of OA. Tgf-ß1 therefore is a potential target for further study for the diagnosis and treatment of TMJ OA.

Co-Expression and Co-Localization of Cartilage Glycoproteins CHI3L1 and Lubricin in Osteoarthritic Cartilage: Morphological, Immunohistochemical and Gene Expression Profiles.

Osteoarthritis is the most common human arthritis characterized by degeneration of articular cartilage. Several studies reported that levels of human cartilage glycoprotein chitinase 3-like-1 (CHI3L1) are known as a potential marker for the activation of chondrocytes and the progression of Osteoarthritis (OA), whereas lubricin appears to be chondroprotective. The aim of this study was to investigate the co-expression and co-localization of CHI3L1 and lubricin in normal and osteoarthritic rat articular cartilage to correlate their modified expression to a specific grade of OA. Samples of normal and osteoarthritic rat articular cartilage were analyzed by the Kellgren–Lawrence OA severity scores, the Kraus’ modified Mankin score and the Histopathology Osteoarthritis Research Society International (OARSI) system for histomorphometric evaluations, and through CHI3L1 and lubricin gene expression, immunohistochemistry and double immuno-staining analysis. The immunoexpression and the mRNA levels of lubricin increased in normal cartilage and decreased in OA cartilage (normal vs. OA, p < 0.01). By contrast, the immunoexpression and the mRNA levels of CHI3L1 increased in OA cartilage and decreased in normal cartilage (normal vs. OA, p < 0.01). Our findings are consistent with reports suggesting that these two glycoproteins are functionally associated with the development of OA and in particular with grade 2/3 of OA, suggesting that in the future they could be helpful to stage the severity and progression of the disease.

Low Levels of Vitamin D have a Deleterious Effect on the Articular Cartilage in a Rat Model.

Vitamin D appears to play an important role in bone and cartilage metabolism since its receptors are widely found in human articular chondrocytes. Thus, effects of variation of vitamin D may directly impact cartilage and bone biology. The aims of this study are to compare (1) articular cartilage structure and composition and (2) trabecular and cortical bone microstructure in rats with normal versus insufficient vitamin D levels. Twenty-five mature, male Sprague-Dawley rats were allocated to two groups: (1) control arm (vitamin D replete-12 rats) and (2) an experimental arm (vitamin D deficient-13 rats). Vitamin D deficiency was induced using a vitamin D-deficient diet and UV light restriction. Rats were sacrificed after 4 weeks vitamin D deficiency was confirmed. The right knee was harvested for analysis of both the medial (MFC) and lateral femoral condyles (LFC). A region of interest was established on both condyles to correlate subchondral bone architecture and the overlying cartilage. Histological analysis was performed and graded using the modified Mankin score. Subchondral and cortical bony architecture was evaluated with micro-CT. After 4 weeks, the vitamin D-deficient group had statistically significant changes in cartilage structure in both the MFC and LFC [1.55 ± 0.6 vs. 4.23 ± 4.1 (p = 0.035) and 1.55 ± 0.6 vs. 3.53 ± 2.4 (p = 0.009), respectively]. Micro-CT analysis revealed no correlation between subchondral bone values and the overlying cartilage Mankin score (p = 0.460). No significant difference was evident between the subchondral bone of the control and study group. Low levels of vitamin D have a deleterious effect on the cartilage. Given the high prevalence of vitamin D deficiency in the general population, these findings raise important questions about the potential role of vitamin D in articular cartilage health.

Association between Wnt inhibitory factor-1 expression levels in articular cartilage and the disease severity of patients with osteoarthritis of the knee.

Wnt inhibitory factor (WIF)-1 is a potent extracellular Wnt antagonist which may be used as a potential molecular therapy for the treatment of inflammatory and autoimmune diseases. Although previous studies have demonstrated that WIF-1 has a protective role in experimental studies of arthritis, its role in the various disease grades of osteoarthritis (OA) remains unclear. A total of 40 patients with various stages of primary OA of the knee and 10 control subjects were enrolled in the present study. Articular cartilage specimens were harvested from subjects following total knee arthroplasty or knee above amputation. Disease severity was determined according to Modified Mankin score and cartilage tissues were ascribed to four groups: Normal, mild, moderate and severe lesions. WIF-1 expression levels in articular cartilage were measured using immunohistochemical techniques. WIF-1 expression levels were detected in all cartilage tissues. As compared with the controls, patients with OA exhibited significantly decreased WIF-1 expression levels in the articular cartilage (0.19±0.05 vs. 0.26±0.04; P<0.01). Furthermore, articular cartilage WIF-1 expression levels in the moderate and severe lesion groups were significantly reduced, as compared with the controls (P<0.01) and mild lesion group (P<0.05). Subsequent analysis demonstrated that articular cartilage WIF-1 expression levels were negatively correlated with the severity of disease (r=-0.896, P<0.001). In conclusion, the results of the present study suggested that WIF-1 expression levels in articular cartilage may be negatively associated with progressive joint damage in patients with OA of the knee; therefore, WIF-1 expression may be a potential indictor for monitoring OA disease severity.

CHI3L1 and lubricin expression in osteoarthritic cartilage

Osteoarthritis (OA) is the most common human arthritis characterized by degeneration of articular cartilage. Several studies reported that levels of human cartilage glycoprotein 39 (GP-39) are known as a potential marker for the activation of chondrocytes and the progression of OA, whereas lubricin appears to be chondroprotective. The aim of this study was to investigate the co-expression and co-localization of CHI3L1 and lubricin in normal and osteoarthritic rat articular cartilage to correlate their modified expression to a specific grade of OA. Samples of normal and osteoarthritic rat articular cartilage were analyzed by the Kellgren-Lawrence OA severity scores, the Kraus’ modified Mankin score and the Histopathology OARSI system for histomorphometric evaluations, and through CHI3L1 and lubricin gene expression, immunohistochemistry and double immuno-staining analysis. The immunoexpression and the mRNA levels of lubricin increased in normal cartilage and decreased in OA cartilage. By contrast, the immunoexpression and the mRNA levels of CHI3L1 increased in OA cartilage and decreased in normal cartilage. Our findings are consistent with reports suggesting that these two glycoproteins are functionally associated with the development of OA and in particular with grade 2/3 of OA evidenced in histomorphometric analysis of our samples, so that they could have a role in the daily clinical practice in staging the severity and progression of the disease.This work was supported by by a Grant-in-Aid provided by FIR 2014-2016, (cod. 314509), University of Catania, Italy.

Decreased Synovial Fluid α-Melanocyte-Stimulating-Hormone (α-MSH) Levels Reflect Disease Severity in Patients with Posttraumatic Ankle Osteoarthritis.

α-Melanocyte-stimulating hormone (α-MSH), an endogenous melanocortin peptide, has been demonstrated to have anti-inflammation effects and protect against cartilage damage. Objective In this study, we aimed to investigate whether α-MSH in ankle joint synovial fluid is associated with the disease severity of posttraumatic ankle osteoarthritis (PTAOA). 66 PTAOA patients undergoing ankle arthroscopical debridement or ankle joint replacement were enrolled in the study. Synovial fluid α-MSH concentrations were explored by a special radioimmunoassay method. Cartilage degradation biomarkers such as collagen type II (CTX-II), aggrecan-1 (AGG-1), as well as inflammatory markers, interleukin-6 (IL-6) and matrix metalloproteinases-3 (MMP-3) in the synovial fluid were determined by enzyme-linked immunosorbent assay (ELISA). The symptomatic and functional severity was evaluated using Teeny-Wiss scoring and AOFAS ankle-hindfoot rating scale. The radiographic progression of PTAOA was identified according to the modified ankle osteoarthritis Kellgren-Lawrence (KL) grading system. The modified Mankin score was used for assessing the histopathological severity for cartilage lesions. Receiver operating characteristic (ROC) curve was conducted and the area under curve (AUC) was used to the evaluate the diagnostic value of α-MSH levels for the prediction of the modified K-L grading by comparing with other biomarkers examined. α-MSH levels in synovial fluid showed a negative correlation with, modified ankle K-L grading, Mankin scores, and degradation biomarkers CTX-II and AGG-1, as well as inflammation markers IL-6 and MMP-3. In addition, α-MSH levels were also positively associated with Teeny-Wiss scoring and AOFAS ankle-hindfoot scores. The AUC area of α-MSH was similar to CTX-II, AGG-1, IL-6, and MMP-3. Synovial fluid α-MSH levels showed an independent and negative correlation with disease severity in patients with PTAOA. Application of α-MSH locally may serve as a potential adjuvant therapy for delaying the process of PTAOA.