Introduction: Recently, tissue engineering based on stem cells has emerged as a new discipline that amalgamates aspects from biology, engineering, material science and surgery and that has as goal the fabrication of functional new tissue to replace damage tissue. The aim of our study was to verify if the pluripotent cells derived from inner mass cell (ICM, Inner Cell Mass) of embryos at the first stages of development (blastocysts), seeded on Tissucol., maintaining them properties, and grow and form cartilage in chondral defects, when used for repair the lesion.

Methods: An osteochondral full thickness lesion was produced in the medial femoral condyles of twelve sheeps. The pluripotent cells were then isolated from feeder layer and seeded on fibrin glue before the transfer. We proceded with aspiration of ES cells in fibrinogen and successively addition of trombin at time to transplantation. The creation of full-thickness defects was performed in such a manner as to render it impermeable to blood-borne cells and signaling substances emanating from the subchondral bone-tissue spaces. After this, into the left knee 170 μl of Tissucol were inserted whether on right knee170 μl of Tissucol with 120.000 ES cells into the hole. The number of stems cells obtained initially correspond to the maximum quantity avalaible before the last differentiation of them.

The new tissue obtained was tested using the ICRS classification, and analysed biomechanically by the Artscan 200 series. We performed besides immunohistochemical evaluation of cartilage to check collagen type I.

Results: The compressive stiffness of the reparative tissue was higher in the treated group (Es cells + Tissucol) mean = 1.02 N than in the control group (Tissucol) mean = 0.68 N).

Four weeks after transplantation immunohistological analysis show in the treatment group cartilaginous tissue; The cells in the repair cartilage were round and arranged in numerous small clumps; the matrix showed strong metacromasia, indicating that this was hyaline cartilage. eight weeks after transplantation, the cells were largely distributed on the area and the repair tissue still resembled hyaline cartilage. After eight weeks the repair tissue implanted was fibrous with prevalence in extracellular matrix of Type II collagen.

Conclusion: Passage in fibrinogen and the addition of thrombin doesn’t alter the properties of the cells; Tissucol mimics embryonic environment and appears to be quite suitable and appropriately flexible delivery vehicle. This repair tissue manifests neither a arcade-like organization of its fibers nor a well-define zonal stratification of its chondrocytes but detection of Type I collagen rendering the pluripotent-cells-fibrin glue complex a possible candidate for the repair of cartilage lesions.

Metallosis is a combined chemical and toxic reaction which, if the wear of a metal implant is large, may cause extensive reaction of synovial membrane and thus triggering the loosening.

We present a case of a 72 year-old man, who underwent to a cemented unicompartimental porous metal coated knee implant because affected by rheumatoid arthritis complicated by osteonecrosis of medial femoral condyle of the knee. Four years after replacement, the patient presented symptoms included moderate swelling, pain, synovitis inability to bear full weight as well as grinding; plain radiographs shows well fixed implant and not finding of loosening of prosthesis; arthroscopy revealed the diagnosis of metallosis. The specimens of synovial tissue were prepared to observation to light and electron microscopy. Total synovialectomy and revison with total knee replacement were successful in relieving the symptoms.

Arthroscopy examination revealed a posterior break of tibial component, source of the release of multiple metal beads; we observe alsogray black discoloration of hypertofic and hyperplastic synovium pannus like; metal beads were detected in the joint space soft tissue and were also embedded in the articulating surface of the tibia component. Microscopic examination shows metal debris as black aggregates and a diffuse sheet like proliferation inside histiocytes of villous membrane. Ultrastructural study demonstrate that the presence of metallic fragments, measuring less than 0.3 micron in diameter is predominantly concentrated inside the macrophage’s phagolisosomes.

Delivery of large number of metal beads from implant and the release of smallest size metal debris play a pivotal role in the development of a foreign body granulomatous reaction. The failure of unicompartimental prosthesis has been accellerated by unperformed sinoviectomy during the first implant; the cells of synovial membrane are continuosly activated, by wear of implant material, to phagocitate and to secrete inflammatory response.

The different spatial sideway of geodes in the same femoral head, their number, dimensions, origin, suggested to us the present document. Before now, it has already been analysed cystic hollows in primary arthrosis. Actually on our study, we relate the outcomes regarding the same phenomenon in rheumatoid arthritis.

Materials and methods. We choose femoral head previously scheduled, considering the same pre-operatory radiographic weightiness diagrams. These were undergone to a parallel and vertical planes cut among them. On three millimetres thickness slices, thanks to constant radiographic enlargement by semiautomatic images analyzator, we detected the number, site and dimensions of geodes. The data obtained, formed into a groups for quadrant (limited by two orthogonal planes crossing the centre of rotation), has been treated by statistical analysis (Anova and t-test).

Results and conclusions. According to preliminary results, it would turn out just one difference between the geodes observed in primary arthrosis and in hip arthrosis secondary to rheumatoid arthritis. This difference it consists in the dimension of cystic hollows that are bigger in rheumatoid arthritis according to the phisiopathology and anatomopathologic particularities.

Introduction: Trabecular metal associated with monob-lock elliptical design represents a valid surgical solution for orthopaedic acetabular reconstructive procedures and second surgery.

Materials and methods: From 1999 to 2004, 61 patients between 45 and 81 years with osteoathritis underwent total hip primary arthroplasties with porous tantalum elliptical cup. We performed clinical evaluation through Harris Hip Score test. Bone-implant interface was studied through radiography with reference to the three Charnley’s areas. Follow-up were performed preoperatively at six months and yearly thereafter.

Results: Clinical results showed high improvement of Harris Hip Score (average preoperatively score was 46, postoperatively 90). Radiographic evaluation revealed a bone apposition to the porous tantalum without radiolucent lines around the acetabular interface. No local (osteolysis) or general (DVT) complication was seen.

Conclusions: Tantalum monoblock elliptical acetabular cup with high volumetric porosity, flexibility and high biocompatibility associated with particular microstructure permits direct apposition of bone, more extensive osseointegration with the maximum bone contact. The trabecular metal cup increases the initial stability helping in the prevention of osteolysis and loosening in a five years follow up.

Introduction: Embryonic stem cells are pluripotent cells derived from internal mass cell (ICM, Internal Cell Mass) of embryon to the first stages of development (blastocisti. The present study has two goals: 1) to isolate, to cultivate, and to characterize embryonic stem cells derived from blastocisti of sheep produced in vitro. 2) to repair the articular cartilage using stem like cells veicolated on fibrin glue.

Materials and Method: In six sheep in correspondence of medialis femoral condilo, at first, it has been produced an osteochondral full thickness lesion and subsequently it is proceeded to the implant of stem like cells, previously isolated by immunosurgey technique and seeded on the fibrin glue. The new tissue obtained, it has been estimated using the ICRS classification, and undergone to a biomechanical analysis by the Artscan 200 series.

Conclusions: It is possible to obtain stem like cells from sheep embryo’s, produced in vitro with elevated differentiative capacity. The passage in the fibrinogeno and then the added of trombina it doesn’t alter the property of cells, rendering therefore the complex stem cellsfibrin glue, a possible candidate for the repair of cartilage lesions.

It is well known that articular cartilage in adults has a limited capacity for self-repair. Numerous methods have been devised to augument its natural healing response, but these methods generally lead to filling of the defect with fibrous tissue or fibrocartilage, which lacks the mechanical characteristics of articular cartilage and fails with time. Tissue engineering combines aspects of cell biology, engineering, material science and surgery to generate new functional tissue and provides an important approach to the repair of articular cartilage lesions and, ultimately, functional success. The purpose of our study was to perform experimental resurfacing of articular cartilage in 18 sheep using different techniques: before implantation in all sheep a full-thickness chondral lesion of medial femoral condyle was created; subsequently, autologous chondrocytes seeded into the matrix were implantd into five sheep; a periosteum flap was implanted in five sheep; and, as source of growth factors, adipocytes by vascular peduncle of Hoffa tissue were implanted in five sheep. The reparative tissue of the chondral lesion was compared with uninjured contralateral knee. The results present the bonding between implantation tissue and host tissue, preservation of phenotypic stability of chondrocytes culture, standard dosage of growth factor secreted by adipocytes and characterisation of the histological properties of reparative tissue, comparing different surgical techniques.

This study was conducted to evaluate the clinical and radiographic results on titanium stems that were similar in design but differed with regard to proximal grit-blasted surface texture with and without a hydroxy-apatite (HA) coating. We evaluated 40 patients who had undergone primary total hip replacement by a postero-lateral approach. The stems, all made of titanium alloy, tapered, grit-blasted, collarless, with anterior-posterior fins, did present some differences: in a group of 20 stems a proximal hydroxyapatite coating (thickness: 50 μm) was implanted; in another group of 20 stems the proximal surface was without HA coating. Clinical and radiographic evaluations were performed pre-operatively at 3, 6 and 12 mounths during the first year; than once for the following years.The mean duration of follow-up was 6 years.

At the final follow-up examination the Harris hip scores in the HA-coated group (mean, 96 points) and non-HA coated group (mean, 94 points) were similar. Bone-remodelling patterns were similar in the groups and the fast bone integration of the HA coated group. In both groups only two cases of aseptic loosening of the stems were found.

After 6 years of follow-up, the clinical and radiographic results among grit-blasted titanium tapered stems with or without Ha coating were perfectly similar. The optimum final bone integration was due just to the singular shape of femur (type B Dorr’s) with an excellent proximal bone stock. The micromotion of implants reduced the bony-anchored stems in two cases.

With the plasma–spray technique of applying a hydrox-ylapatite (HA) coating bone ingrowth can be enhanced and early migration of hip prostheses reduced. The significance of coating resorption is controversial. In this study the bone growth and the degradation of the HA coatings were evaluated and compared by SEM.

Premature loosening was identified in four cups with an Ha coating over a porous-coated surface 3 years post-operatively.The Ha coating has a thickness of up to 50 μm. The cup specimens were soaked in 6% sodium hypochlorite to render them anorganic, dehydrated, and sputter-coated with gold-palladium. Secondary electron images of all specimens were obtained by field emission SEM (Zeiss:DSM.962).

Ultrastructural analysis showed that all porous-coated Ha-coated cups had bridges of lamellar bone in direct contact with the implant surface (30% bone in-on growth). Different types of coating degradation were observed. Delamination between the coating and implant surface releases numerous particles or fragments; the resorption by osteoclasts of the amorphous phase was shown to expose the crystalline phase of the coating grains.

This study suggests that resorption disintegrates the Ha coating and reduces the bonding strength between implant and bone and the strength of the coating-implant interface, which might lead to implant loosening,coating delamination and acceleration of third-body wear processes.

Arthoscopic biopsy provides adequate tissue for most diagnostic requirements. Examination of endoarticular tissue can assist in the diagnosis of some joint infections; sometimes cultures of synovial tissue may be positive even when blood and synovial fluid cultures have been negative. In chronic infections such as tuberculosis and fungal disease, and characteristic synovial lesions, such as granuloma, it may be advised. Both gout and pseudo-gout can demonstrate tophus-like deposits in synovial tissue. Synovial biopsy can have a major role in the diagnosis of synthetic arthritis after ACL reconstruction with synthetic ligaments to identify a foreign body granulomatous reaction to particulate material implant or to verify the arthroplasty effect after loosening of a knee prosthesis.

There is a lack of association between arthroscopic findings and clinical laboratory and radiological features of arthritis. The general diagnosis of rheumatoid arthritis (RA) is usually based on characteristic clinical, radiological and serological manifestations. Synovial biopsy in RA is not normally required for diagnosis because the appearance is not specific, but it may provide important prognostic information. Synovial chondromatosis and pigmented villonodular synovitis are tumours of the synovial membrane that require biopsy for diagnosis. The biopsy of articular cartilage is useful to evaluate the capacity of chondrocytes to proliferate and to test the regeneration of cartilage after resurfacing by autologous chondrocytes implantation or other techniques. Histological confirmation could improve the prognosis of the knee during arthrofibrosis (percentage of elastic fibres), fibrosis of Hoffa disease and cyclop lesion. Another application is study of ligamentisation phenomena after anterior cruciate reconstruction and the presence in osteoarthritic knees with degenerative changes in posterior cruciate ligament.

The compressive stiffness of cartilage is primarlly determined by proteoglycan, whereas the tensile properties are determined by collagen fibres. The first alteration in cartilage structure during cartilage degeneration is the decrease in proteoglycan content and increase in interstitial water; consequently, cartilage becomes softer and cartilage stiffness decreases. The pupose of our study was to evaluate arthroscopically the compressive stiffness of cartilage in different areas of living human knee joints. Detection of softening is revealed in vivo by using an indentation instrument (artscan 200). The instrument is composed of a measurement rod joined to the handle; in the distal end of the rod, there is an inclined flat surface with a separate plane –ended cylindrical indenter. During measurement the distal end of the instrument is pressed against the articular surface while the indenter imposes constant deformation on the cartilage. The maximal indenter force, by which the tissue resists the constant deformation, is measured with strain gauge transducers. We performed indenter tests in knees joints in which cartilage was diagnosed as normal; stiffness of articular cartilage was also measured during arthroscopy in knees before ACL reconstruction, in knees with closed chondromalacia (ICRS grade 0–1) and in osteochondral lesions (ICRS OCD grade 1) and the data compared with areas of normal cartilage.

Aims: Hydroxylapatite (HA) coating is able to enhance bone ingrowth and to reduce early migration of hip prostheses. The optimum coating quality and surface texture is still a matter of debate. Moreover, the signiþ-cance of coating resorption is controversial. In this study the degradation of the coatings HA was evaluated and comparate by SEM. Materials and methods: Four cups with HA coating over a porous-coated surface was iden-tiþed with premature loosening at 2–3 years post-operatively. The HA coating has a thickness of up to 50 μ. The cup was stored in formalin before the SEM analysis. The cup specimens was soaked in 6% sodium hypochlorite to render them anorganic, dehydrated, sputter Ð coated with gold-palladium. Secondary electron images of all specimens were obtained by þeld-emission SEM (Zeiss: DSM.962). Results: Ultrastructural analysis showed that all porous-coated HA coated cups had bridges of bone in direct contact with the implant surface (30% bone on-growth). Different types of coating degradation were observed. Delamination between the coating and implant surface; release of numerous particles or fragments ranging from a few to several dozens of microns. Under high magniþcation resorption of the amorphous phase is shown to be exposing the crystalline phase of the coating grains so that the grain boundaries become fragile and easily to be phagocytosed by osteoclasts. Conclusions: This study suggested that resorption disintegrates the HA Ð coating and reduces the bonding strength between implant and bone and the strength of the coatingÐimplant interface, which might lead to implant loosening, coating delamination and acceleration of third body wear processes.