Biomedical subjects

G Zatti

Publications and source records attributed to G Zatti.

27 records · Page 2Linked to original sources

PubMed1989

An analysis of the changes in the surfaces of metallic femoral components in hip prostheses. A study of 60 prostheses removed after 1-20 years.

A study of 60 femoral prosthetic components removed after 1-20 years allowed us to study the behaviour of the metallic surface in real life conditions. Changes were observed exclusively in cemented prostheses. They consisted of corrosion phenomena characteristic of the components of steel EN 58 J and 316 S, and wear phenomena secondary to mobilisation. The latter were observed in steel components as well as in those in Co-Cr alloy. The areas of corrosion in the steel prostheses were characteristically distributed, indicating a combination of causal factors, including an insufficient capacity of passivation of the metal and the particular situation of the cement-to-metal interface.

Chromium Alloys↗

PubMed1988

The role of mineralization in experimental models of osteogenetic induction with decalcified bone matrix.

The role of mineralization was studied in an experimental model of osteoinduction consisting of the implant of decalcified bone matrix in the rat muscle. After vascular connective tissue invasion of the matrix, the first phenomena is the appearance of hydroxyapatite crystals in the area of chondroid metaplasia from where the deposit of calcium-phosphate is extended to the surrounding decalcified matrix. The recalcified areas act as a substratum for the neo-osteogenesis. The appearances observed reproduced those of enchondral ossification, where the first osteoblasts differentiated on the calcified cartilaginous matrix and began to supply new bone matrix. Non-decalcified bone matrix implants were surrounded by a connective tissue capsule with features identical to those of a foreign body reaction and with total absence of vascular invasion. The absence of induction in this type of implant may be related either to masking of the osteoinducing protein in the calcified matrix, or to the absence of cells with osteogenic differentiation potential due to the lack of cellular invasion of the implant.

Animals↗

PubMed1988

Isoelastic shoulder prostheses. Considerations on use and results.

The principles underlying the use of isoelastic shoulder prostheses are discussed and the results obtained in 8 patients are reported. Two operations were for pseudarthrosis of the humeral neck and 6 for osteolytic neoplasms. The results were assessed after an average follow-up of 4 years. Full movement was never recovered; there was partial recovery in 6 cases, and no significant recovery in 2. The extent of the surgical resection was determined by the type of lesion; in more conservative resections which allowed for the reconstruction of tendinous insertions, the functional results were better than in wide resections. The difficulty of recovering good movement was related to the limited possibilities of reconstructing the insertions of the external rotator muscles.

Adult↗

PubMedDate not supplied

Complex fractures of the femur: treatment with a long gamma nail: short- and medium-term experience.

The introduction of the gamma nail and of the long gamma nail, associating the principle of intramedullary nailing and of the sliding screw-plate, has led to good results in the treatment of complex fractures such as per-sub-trochanteric fractures and associated fractures of the femoral neck-diaphysis. In this study, our experience with the long gamma nail (Long Gamma Nail Howmedica) is presented. Of the 43 patients treated between 1993 and 1998, 21 (49%) with a mean follow-up of 2.5 years (1-5 years) were reviewed. Clinical and a radiographic evaluations were obtained for each of the patients. This study showed that there was a high incidence of poor consolidation (dysmetria in 10 patients, torsion deficit in 7, consolidation in varus of the femoral neck in 1 patient) particularly in associated fractures of the femoral neck and diaphysis, accompanied, however, by good functional recovery (only 3 patients with modification in the angle of progression of the foot) and by the satisfaction of the patients questioned. Thus, indications for the use of this device in proximal fractures of the femur, particularly in elderly patients and in high-energy traumas, are demonstrated.

Adult↗

PubMedDate not supplied

The surgical treatment of fractures of the proximal end of the tibia: a review of cases as related to prognostic factors.

It is the purpose of this retrospective study to analyze factors capable of influencing clinical-functional and radiographic results, such as type of fracture, age of the patients, type of trauma, delay in treatment, associated lesions. A total of 33 fractures treated by open reduction and internal stabilization for fractures of the proximal tibia classified according to the AO were re-evaluated. Clinical and radiographic evaluation were obtained by assessing arthrosis, axis, and sinking of the tibial plateau. The clinical and functional results were satisfactory in 72.2% of cases, and radiographic ones were satisfactory in 63.6% for gonarthrosis, in 81.6% for axis, and in 84.8% for sinking. In conclusion, factors capable of influencing the results, such as type of fracture, age of the patient, and type of trauma, in addition to variables that the surgeon must monitor, such as reconstruction of the joint, alignment, synthesis, treatment of meniscal lesions, were observed.

Adolescent↗

PubMedDate not supplied

The surgical treatment of supracondylar fractures of the humerus in children by percutaneous fixation using Kirschner wires: analysis of residual deformities.

The authors report the results of the surgical treatment of supracondylar fractures of the humerus during childhood by closed reduction and percutaneous synthesis using Kirschner wires. A total of 16 patients were considered, who were re-examined at a mean follow-up of 57.9 months (24-84). The fractures were evaluated according to the Gartland classification modified by Wilkins. The results were classified based on Flynn criteria, and the duration of hospitalization and early and late complications such as neurovascular deficit and residual deformities were also taken into consideration. Final results were satisfactory in 94% of cases with no septic, vascular, or nervous complications. We observed remodeling of three fractures with defect in reduction of the distal fragment on a sagittal plane, and the absence of correction in a case of deficit in reduction on the frontal plane. Deformity persisted with no secondary displacement in 5 cases with correct postoperative reduction.

Adolescent↗

PubMedDate not supplied

Peritalar release in the treatment of congenital talipes equinovarus clubfoot.

It is the purpose of this retrospective study to evaluate the results of the surgical treatment of congenital talipes equinovarus clubfoot. Seven patients affected with congenital talipes equinovarus clubfoot, 2 of which bilateral, treated surgically using peritalar release according to Simons were re-examined. The long-term follow-up results obtained after an average of 4 years were evaluated from clinical, morphofunctional, and radiographic points of view, and with the help of a photopodogram and computed baropodometry. The subjective satisfaction of the patients was also evaluated. Results were considered to be good in all of the cases. In conclusion, surgery involving peritalar release allows for correction of abduction of the forefoot, and restores physiological calcaneal valgus, re-balancing standing on the plantar surface; the persistence of an area of hypostanding in the forefoot operated on and of mild, residual cavus of the plantar arch do not, thus, seem to influence the good results obtained.

Child, Preschool↗

PubMedDate not supplied

Stem revision: special implant versus primary device.

The purpose of hip revision surgery is to relieve pain and restore hip function, while improving hip biomechanics and bone stock. The entity of bone stock impairment due to lysis indicates to the surgeon which revision stem he would preferably choose. Modern literature has described several options for stem revision, ranging from primary cemented/less implants in the case of limited proximal bone defects, to special revision stems where a massive femoral bone stock impairment is present. There are many classifications of the femoral bone-stock loss in the literature but most authors seem to agree that the treatment of minimal proximal defects should be performed with primary implant stems. The need to bridge a bigger bony gap makes distal fixation a good deal. Two options are described for this purpose: the Wagner stem and modular stems. Wagner's concept consists of a distal fixation based on the interference of the straight tapered titanium alloy stem at the level of the femoral isthmus, while longitudinal fins provide rotational stability. A wide variety of modular stems was lately developed to prevent major complication associated to the Wagner's stem, but some new problems arose from proximal overfill of the canal, difficult in assembly and fretting corrosion. Early experience with the new ZMR taper (Zimmer, Warsaw, IN, USA) modular revision stem is reported.

Adult↗

PubMedDate not supplied

Two-stage revision surgery to treat an infected hip implant. A comparison between a custom-made spacer and a pre-formed one.

A retrospective study was conducted to evaluate the results of two-stage surgical treatment for infected hip implant using two different spacers in antibiotic-impregnated cement, one custom-made and one pre-formed. Out of a total of 20 patients treated between 1995 and 2003, the temporary implant of one custom-made spacer was carried out in 8 cases, while in the remaining 12 cases we resorted to using a pre-formed spacer (Spacer G). In both groups we observed one recurrence of infection, for an overall 90% success rate in terms of eradication of the infection. Custom-made spacers had a greater incidence of local complications (1 breakage, 1 dislocation, 1 sinking of the revision stem) as compared to pre-formed ones (1 dislocation). The clinical results evaluated using the Harris Hip Score showed a statistically significant difference (p < 0.05) in both groups as compared to the preoperative score. The use of a pre-formed spacer, although more costly as compared to that custom-made one, was advantageous in some ways, for example in terms of standardization of the implant method, the lower incidence of mechanical complications and the better functional results.

Aged↗