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Biomedical subjects

G Zatti

Publications and source records attributed to G Zatti.

At least 19 recordsLinked to original sources
PubMed2007

Popliteal artery pseudoaneurysm after a revision of total knee arthroplasty: endovascular treatment with a stent graft.

Injury to the popliteal artery during total knee arthroplasty is a very rare but dangerous complication. Several mechanisms are capable of generating a direct trauma to the vessel, like posterior retractor and oscillating saw. We report a case of popliteal artery pseudoaneurysm in a 52-year-old woman that occurred during revision of total knee arthroplasty, requiring emergency repair by means of percutaneous endovascular covered stenting.

Aneurysm, False↗
PubMed1998

The relevance of hydroxyapatite and spongious titanium coatings in fixation of cementless stems. An experimental comparative study in rat femur employing histological and microangiographic techniques.

Pure titanium rods plasma-spray coated with hydroxyapatite (HA) or porous titanium (Ti) of controlled roughness were implanted bilaterally in the distal femur of Sprague-Dawley rats to compare the extent of bone growth on the two types of coating. The relevance of other factors, like mechanical stability and biological adaptation of the bone to the insertion of a foreign body implant, were investigated in femora which were over-reamed (absence of primary fit) or reamed without insertion of the rod. Continuous tetracycline labeling for the first 30 days and for the last 2 weeks in the 90-day group was performed; histological/histometric, fluorescence and microangiographic studies were carried out on serial sections of the implanted and control femora. In the group of stable implants, HA-coated rods showed 90% integration versus 53% with Ti-coated implants (P < 0.001); in over-reamed implants neither surface bone growth nor endosteal fixation occurred, and both types of rods were surrounded by a thick layer of connective tissue. The study documented early adhesion of osteoblasts and direct deposition of bone matrix on the substrate, while on spongious titanium osteogenesis was observed only in proximity to the surface. Remodeling of the reactive, primary bone to mature, lamellar bone took the form of a capsule surrounding the implants and radial bridges connecting the latter to the endosteal surface. The number, height and thickness of these bridges appeared to be the factors determining implant stability, rather than the extent of the bony capsule on the perimeter of the implant. Integration was a function not only of mechanical conditions and surface geometry, but also of the biological response of the whole bone to changes in the vascularization pattern. The reported phenomena can be seen more easily in experimental models involving small rodents because of their fast bone turnover and revascularization, but it is expected that they take place, even at a lower speed, in clinical situations like cementless stems of total hip replacement.

Angiography↗
PubMed1998

Treatment of closed humeral shaft fractures with intramedullary elastic nails.

PURPOSE: Our purpose is a retrospective study of the results of diaphyseal humeral fracture treatment by elastic intramedullary nailing in comparison with plate osteosynthesis. METHODS: Thirty cases were reviewed, with an average follow-up of 2 years. In 14 cases, flexible nails were used, and in the remaining 16 cases, A-O plates were used. We considered patients' sex and age, fracture type according to the A-O classification, type of treatment, consolidation defects, additional therapeutic procedures, healing time, and functional recovery. The surgical technique of elastic nailing appeared very simple, safe, and rather atraumatic because the nail is introduced in a retrograde manner and does not need proximal interlocking. RESULTS: The results of elastic nailing, in terms of fracture healing time and functional recovery, appeared comparable with the results of plating, and complications appeared milder. CONCLUSION: We conclude that intramedullary elastic nailing is valid for routine use in appropriately selected humeral shaft fractures.

Adolescent↗
PubMed1994

Histology of the metal-bone interface: interpretation of plastic embedded slides.

The interference of processing and preparation of histological slides for the study of morphology and morphometry of bone-implant interfaces was investigated in an experimental model, in which a titanium plate was inserted through the cortical bone into the medullary cavity of rat tibiae. The thickness of the sections, burr and notching of the cut border, and staining properties of the embedding resin were found to significantly influence the appearance of the bone-implant interface and, when morphometry was applied, the extent of direct bone-metal contact. The model of the interface resulting from this study is that of some bony processes abutting on the metal surface, while most of the contact is between metal and connective tissue or vascular spaces.

Animals↗
PubMed1994

Reversibility of the inhibitory effect of salmon calcitonin on bone resorption in rats.

Inhibition of osteoclastic bone resorption has been induced in growing rats with high doses of salmon calcitonin. This effect was evaluated by measuring the perichondrial ring height of the proximal tibial metaphysis. The aim was to assess whether osteoclastic activity resumed after a period of inhibition with high doses of calcitonin. 20 male Sprague-Dawley rats were treated for 21 days with 100 units/kg/day of salmon calcitonin subcutaneously and killed after 0-60 days, together with non-treated controls at 0 and 60 days. Arrest of metaphyseal modeling and increased height of the perichondrial ring at the end of the period of therapy (P 0.002 versus controls) were observed. Recovery of bone resorption was evident 20 and 40 days after withdrawal of calcitonin.

Animals↗
PubMed1993

Experimental model in vivo for quantitative assessment of bone resorption inhibition.

Quantitative assessment of bone resorption inhibition in vivo is not easily accomplished; methods relying on a count of osteoclasts are questionable, and histomorphometric evaluation of the bone mass presents several technical problems as well. The authors developed a simple method to measure the inhibition of bone resorption by study of the proximal tibial metaphysis of growing rats: the height of the perichondrial bone ring was taken as an index of the balance between osteoblastic and osteoclastic activity because any agent that inhibits osteoclasts (without interference with osteoblasts) produces an increase in the height of this anatomical structure. Since the ring is well demarcated by surrounding tissues, its height can be measured with accuracy and used for quantitative assessment of bone resorption inhibition. This model was tested with salmon calcitonin, and it provides evidence in vivo that this hormone inhibits osteoclastic bone resorption.

Animals↗
PubMed1993

Inhibitory effect of salmon calcitonin on bone resorption: morphological study of the tibial growth plate in rats.

Salmon calcitonin (sCT) at doses of 100 and 50 UI given subcutaneously to growing rats produced in vivo evidence of osteoclastic activity inhibition. Histological assessment was carried out by measuring the perichondrial ring of Lacroix height, and a dose-correlated effect was found. These aspects were coupled with an increase in the osteoclast number and suggested that in studies with bone resorption inhibitors, morphological evaluation based on osteoclasts count is not reliable. The changes of the metaphysis suggested also that sCT affects the activity of hypertrophic chondrocytes of the growth plate. Plasma calcium levels did not differ significantly between treated rats and controls; an increased phosphatemia was observed in sCT-treated animals.

Animals↗
PubMed1993

Chronic intoxication by ethane-1-hydroxy-1,1-diphosphonate (EHDP) in a child with myositis ossificans progressiva.

A child with myositis ossificans progressiva was treated for 8 years with ethane-1-hydroxy-1,1-diphosphonate (EHDP) 30-40 mg/kg per day. Latterly he complained of severe, progressive bone and joint pain which made standing and walking almost impossible. A radiographic skeletal survey showed diffuse ricket-like lesions. Withdrawal of EHDP therapy produced substantial improvement in his general condition as well as in the radiographic appearance of the bones. Multiple exostoses were observed in this case and, particularly those around the knees, presented a peculiar morphology. This supports the theory that exostoses originate from a defect of metaphyseal modelling.

Adolescent↗
PubMed1993

Evaluation of hollow and full stems implanted in the rabbit tibia: preliminary results.

Full and hollow stems were implanted in the right and left tibiae of five rabbits to study the effects of the implant shape on revascularization and remodelling of the bone after 6 months. No significant difference of periosteal and endosteal circumference was observed when the left and right tibiae of each group were compared. Medullary area was, not surprisingly, significantly smaller in the full stem implanted tibiae. The cortical bone area result was significantly higher in the hollow stem group. In hollow stems, vessels were present both inside and outside the implant with connections through the holes of the implant. The observed differences of cortical bone area can be explained in terms of increased vascular spaces inside the cortical bone of full stem implanted tibiae. This supports the hypothesis that hollow implants provide more space for medullary revascularization and are consequently capable of inducing less endosteal remodelling. Cementless prostheses rely for mechanical fixation on a large interface of the implant with bone. Two factors, i.e. revascularization of the medullary canal and stiffness of the stem, can have a relevant effect on the quality of interface. This non-weight-bearing model suggests the relevance of vascular factors.

Animals↗
PubMed1992

Treatment of slipped capital femoral epiphysis: evaluation of the results of extracapsular epiphysiodesis and open reduction-epiphysiodesis.

The authors review 26 patients who underwent either "in situ" extracapsular epiphysiodesis or intracapsular reduction followed by epiphysiodesis for slipped capital femoral epiphysis (SCFE). A total of 32 operations were performed. In the first group (chronic grade II SCFE), no complications occurred in the 16 operations and the results were excellent in all cases. In the second group (chronic grade II and III SCFE and acute-on-chronic SCFE), in 16 operations we observed four cases of avascular necrosis, two of which accompanied by chondrolysis. Three of these were in cases of acute-on-chronic SCFE. The results confirm that the cases of acute-on-chronic SCFE have the worst prognosis and a much higher risk of avascular necrosis and/or chondrolysis than purely chronic SCFE. Early diagnosis of ischemic complications make it possible to maintain the spherical shape of the femoral head and good joint function. The results are considerably better than in untreated cases.

Adolescent↗
PubMed1992

Bone changes of mucolipidosis II at different ages. Postmortem study of three cases.

Bone changes are a constant feature of mucolipidosis II, with striking differences between newborns and older children. Intracellular, membrane-bound vacuoles were found in the chondrocytes, osteoblasts, osteocytes, and stromal fibroblasts of three affected children. Osteoclasts and marrow cells were unaffected. Ricketslike lesions were present at birth in the two younger cases, whereas signs of high bone turnover and defective calcification were no longer present in the older child. Severe abnormalities of the metaphyseal plate with the loss of normal cartilage architecture and the absence of endochondral ossification were the major changes in this age group.

Age Factors↗
PubMed1991

Fracture with loss of the proximal femur in a child. A case report.

An 8 year old child was involved in a road accident and sustained a large wound in the left groin; radiographs showed a fracture with loss of the proximal femur. After skeletal traction for 80 days, there was bony regeneration of the proximal femur. At 8 months she was able to walk without support and her left leg was 2 cm only shorter than the right.

Bone Regeneration↗
PubMed1990

Experimental osteoporosis in the rat induced by a hypocalcic diet.

The administration of a diet deficient in calcium in the rat quickly produces a reduction in the skeletal mass, with narrowing of the diaphyseal cortex, and less density of the metaphysis. The bone mineral content, determined by a double ray photonic mineralometer, is significantly lower as compared to controls, while histological examination does not reveal defects in calcification. The pathogenetic mechanism is characterised by stimulation of the parathyroid glands in response to a decrease in plasma calcium determined by the insufficient diet. We observed a bone response in two phases: the first, with elevated velocity of remodelling and prevalence of osteoclastic resorption despite the presence of intense osteoblastic activity; the second, with reduced bone remodelling (except for the metaphyseal area). Although these observations do not imply that human osteoporosis involves the same pathogenetic mechanism, it appears possible to use this experimental model to study the effects of endocrine and pharmacological factors on the activity of bone remodelling, which also in human osteoporosis is characterised by the prevalence of osteoclastic resorption.

Animals↗
PubMed1989

Study of the osteoconductive properties of bioactive glass fibers.

Bioactive glass fibers have been prepared and implanted in cortical defect and in muscle. The fibers can act as a substrate for bone apposition, when implanted in a cortical defect, and become incorporated in the new bone matrix. The same results were obtained when fibers were implanted in a muscle pouch together with bone marrow cells. An intense inflammatory reaction was observed when bioactive glass fibers were implanted in muscle; the reaction was milder when fibers were implanted in bone or in muscle together with bone marrow cells. This fact supports the hypothesis that osteogenic cells adhere in an early phase to the substrate and prevent recognition of the foreign material by inflammatory cells. This appears to be a fundamental condition for direct bone matrix apposition on the surface of fibers.

Animals↗
PubMed1989

Neonatal mucolipidosis 2. The spontaneous evolution of early bone lesions and the effect of vitamin D treatment. Report of two cases.

Evolution of the early bone lesions in two children with mucolipidosis 2 was followed from birth. The progression of the bone changes did not differ from healing of rickets. Low levels of 1,25-(OH)2-D3 were found in one child and he was treated with vitamin D; resolution of the rachitic changes was more rapid than in the untreated child. It is suggested that in mucolipidosis 2 bone reacts to two independent factors, one controlling calcium metabolism, the other depending on the primary lysosomal enzyme defect. Since ricket-like features are not present in the other mucolipidoses or mucopolysaccharidoses, the defect of calcium metabolism seems to be related to the specific enzyme defect of mucolipidosis 2.

Aging↗
PubMed1989

Ossification of a perineal haematoma consequent to dislocation of the symphysis pubis.

The authors discuss an unusual complication of dislocation of the symphysis pubis in a female aged 11 years, consisting of an ossified perineal haematoma on one side of the vagina and in the corresponding labrum minore. The most probable pathogenetic hypothesis is that fragments of the periosteum of the pubis remained included in the haematoma, and this was followed by gravitation towards the more dependent tissues.

Child↗