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Aim. To determine whether viscosupplementation with intra-articular (i.a.) low- or high-molecular-weight hyaluronate (HA) injections influenced both chondral and synovial lesions in rats with surgically-induced OA knee. Methods. On D0, rats underwent anterior cruciate ligament transection (ACLX) and were divided in 4 groups: sham group, ACLX-saline control group, ACLX-hyaluronate group, ACLX-hylan group. IA injections were performed on D7, D14 and D21. Histological grading of chondral and synovial lesions were performed on D28. Concomitant immunostainings of Caspase3a and Hsp70 were also performed. Results. Articular damages were significantly reduced in both HAs-treated knee joints. In contrast, a significant increase of histological score of synovial inflammation was noted in both ACLX + HAs groups. Apoptotic events significantly decreased as anti-apoptotic Hsp70 expression increased significantly in both HAs groups. Conclusion. HAs may exert, independently of its molecular weight, ambivalent properties on articular structures, simultaneously exerting chondroprotective properties and promoting long-term subacute synovitis. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cells (MSCs) are regarded as a potential autologous source for cartilage repair, because they can differentiate into chondrocytes by transforming growth factor-beta (TGF-β) treatment under the 3-dimensional (3-D) culture condition. In addition to these molecular and biochemical methods, the mechanical regulation of differentiation and matrix formation by MSCs is only starting to be considered. Recently, mechanical loading has been shown to induce chondrogenesis of MSCs in vitro. In this study, we investigated the effects of a calibrated agitation on the chondrogenesis of human bone MSCs (MSCs) in a 3-D alginate culture (day 28) and on the maintenance of chondrogenic phenotypes. Biomechanical stimulation of MSCs increased: (i) types 1 and 2 collagen formation; (ii) the expression of chondrogenic markers such as COMP and SOX9; and (iii) the capacity to maintain the chondrogenic phenotypes. Notably, these effects were shown without TGF-β treatment. These results suggest that a mechanical stimulation could be an efficient method to induce chondrogenic differentiation of MSCs in vitro for cartilage tissue engineering in a 3-D environment. Additionally, it appears that MSCs and chondrocyte responses to mechanical stimulation are not identical. [ABSTRACT FROM AUTHOR]

Both chondrocytes and mensenchymal stem cells (MSCs) are the most used cell sources for cartilage tissue engineering. However, monolayer expansion to obtain sufficient cells leads to a rapid chondrocyte dedifferentiation and a subsequent ancillary reduced ability of MSCs to differentiate into chondrocytes, thus limiting their application in cartilage repair. The aim of this study was to investigate the influence of the monolayer expansion on the immunophenotype and the gene expression profile of both cell types, and to find the appropriate compromise between monolayer expansion and the remaining chondrogenic characteristics. To this end, human chondrocytes, isolated enzymatically from femoral head slice, and human MSCs, derived from bone marrow, were maintained in monolayer culture up to passage 5. The respective expressions of cell surface markers (CD34, CD45, CD73, CD90, CD105, CD166) and several chondrogenic-related genes for each passage (P0–P5) of those cells were then analyzed using flow cytometry and quantitative real-time PCR, respectively. Flow cytometry analyses showed that, during the monolayer expansion, some qualitative and quantitative regulations occur for the expression of cell surface markers. A rapid increase in mRNA expression of type 1 collagen occurs whereas a significant decrease of type 2 collagen and Sox 9 was observed in chondrocytes through the successive passages. On the other hand, the expansion did not induced obvious change in MSCs gene expression. In conclusion, our results suggest that passage 1 might be the up-limit for chondrocytes in order to achieve their subsequent redifferentiation in 3D scaffold. Nevertheless, MSCs could be expanded in monolayer until passage 5 without loosing their undifferentiated phenotypes. [ABSTRACT FROM AUTHOR]

The article discusses the results of a study of the extent of chondrocyte apoptosis using concomitantly TUNEL method and caspase 3 immunostaining. It also investigates the severity of chondrial lesions in articular cartilage determined at key points from rat knees with mono-iodo acetate and surgical-induced osteoarthritis. The relationship between the TUNEL method and caspase 3 immunostaining is also examined.

Introduction: Desmoplastic fibroblastoma is a rare, slow-growing benign soft tissue tumor. It has a wide anatomical distribution and mainly affects adult males. Fourteen percent of cases occur in the ankle or foot., Case Report: In this study, we report a rare location of desmoplastic fibroblastoma on the ankle of a 76-year-old female, discovered as a slowly growing mass., Discussion: Desmoplastic fibroblastoma is an anatomical and clinical entity. It appears macroscopically as a pseudocartilaginous structure and histologically as a stellate or spindle-shaped fibroblastic proliferation in a collagenous stroma., Conclusion: Desmoplastic fibroblastoma has anatomical specificities and should still be clearly distinguished from certain malignant tumors., Competing Interests: Conflict of Interest: Nil, (Copyright: © Indian Orthopaedic Research Group.)

Joint cartilage has a poor intrinsic ability to heal. Common surgical treatments for traumatic lesions, after debridement of the chondral defect, include stimulation of subchondral bone (microfracture), perichondrial or periosteal grafting, and mosaicplasty (osteochondral cylinder transplantation). Autologous chondrocyte transplantation (ACT) was the first application of cell therapy to orthopaedic surgery. Despite promising results, several groups have tested tissue engineering protocols based on ex vivo colonization of biodegradable polymer matrices that are subsequently transplanted to the target site. Tissue engineering as a treatment for osteoarthritis is even more challenging. Transplantation of genetically modified cells is an interesting concept, based on the production of therapeutic proteins directly at the target site.

Many properties of porous calcium phosphate ceramics have been described, but how pore size influences bony integration of various porous ceramics remains unclear. This study was performed to quantify the bony ingrowth and biodegradability of two porous calcium phosphate ceramics with four different pore size ranges (45-80 microm, 80-140 microm, 140-200 microm, and 200-250 microm). Hydroxyapatite (HA) and beta-tricalcium phosphate (TCP) cylinders were implanted into the femoral condyles of rabbits and were left in situ for up to 12 months. The percentage of bone ingrowth and the depth of ingrowth within the pores were determined. Biodegradability of the implants was also evaluated. Bone ingrowth occurred at a higher rate into the TCP than into the HA ceramics with the same pore size ranges. The amount of newly formed bone was statistically smaller (p < 0.05) into ceramics with 45-80 microm pore size than with larger pore size, whatever the implantation time for HA and until four months for TCP. No statistical difference was noted between the three highest pore size ranges. No implant degradation was noted up to four months. Our results suggest that a pore size above 80 microm improves bony ingrowth in both HA and TCP ceramics. Bone formation was higher in the TCP than in the HA implants.

Unstable pelvic ring injuries are severe injuries, with high morbidity and mortality rates. Since 1994, the authors have been using external fixation to treat these injuries. They present the results achieved in a series of 22 cases of unstable pelvic ring injuries admitted to their institution between 1994 and 2001. External fixation was performed in all cases with pins inserted between the anterior superior and the anterior inferior iliac spine. Posterior injuries were treated operatively in four cases and non-operatively in others. The average age of the patients was 32 years (range: 22 to 56 years). According to Tile's classification, there were 10 type B and 12 type C injuries. Functional evaluation using Majeed's score at the time of review showed a mean score of 75.6 (range: 12-100). The pain score was 22.7/30. Radiological results were good in horizontal injuries, with satisfactory reduction of the symphyseal disruption. In vertical shear injuries however, skeletal traction alone did not achieve accurate posterior reduction in four cases, in which internal fixation was required. Anteroinferior placement of external fixation pins appears as a safe technique with a potential for increased stability of fixation. Associated posterior injuries must be treated with direct internal fixation in cases with vertical instability in which heavy skeletal traction has failed to achieve reduction.