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Biomedical subjects

A Giunti

Publications and source records attributed to A Giunti.

At least 55 records · Page 3Linked to original sources
PubMed1992

Microradiographic and histochemical evaluation of mineralization inhibition at the bone-alumina interface.

Microradiographic and histochemical tests were used to examine the behaviour of the bone tissue close to the alumina coating in cementless hip prostheses which were radiologically stable and explanted because of pain. The presence was detected of a decalcification stripe of the bone tissue with a thickness of about 300 microns, parallel to the prosthesis profile and in appearance not influenced by the roughness of the surface. This phenomenon was attributed to the presence of aluminium ions similarly to what happens in osteomalacic osteodystrophy in nephropathic dialysed patients. It was concluded that the phenomenon must be carefully considered because, in the long term, it could cause failure in the alumina coating.

Aluminum↗
PubMed1990

Arthroprosthetic reimplantation with bioceramics.

The study analyzes the results obtained in 50 cases of arthroprosthetic substitution surgery performed as a result of "aseptic detachment of the implant"; it involves a consecutive series of operations performed between 1979 and 1983. In all of the cases ceramic-ceramic cemented prostheses were implanted. The results, which were generally satisfactory, confirmed the excellent properties of alumina (low wear, elevated tolerance).

Adult↗
PubMed1989

Neoadjuvant chemotherapy for localized Ewing's sarcoma of the extremities: preliminary results of a protocol which uses surgery (alone or followed by radiotherapy) for local control.

From June 1983 to December 1985, thirty-eight patients with localized Ewing's sarcoma of the extremities were treated with a protocol that consisted of an initial nine week period of polychemotherapy (vincristine, adriamycin and cyclophosphamide) followed by local therapy and additional chemotherapy (vincristine, adriamycin, cyclophosphamide and dactinomycin) for one year. As local treatment all patients were offered surgery; thirty-two accepted and six refused. These six patients were locally treated with radiotherapy alone (50 Gy). In the remaining patients an amputation was performed in one case and a resection in thirty-one. In resected patients when a wide margin was achieved (24 cases) no further local treatment was performed; when it was marginal (5 cases) or intralesional (2 cases) radiotherapy at lower doses (40 Gy) followed. At mean follow-up of thirty-seven months the percentage of continuously disease-free patients was 50% for those treated with radiotherapy, 76% with surgery, and 85% with surgery and radiotherapy. Eight patients developed metastatic disease and two patients had local recurrence and metastases. The local recurrences were seen in one patient locally treated with surgery and in one locally treated with radiotherapy. Nine major local complications were observed: three in patients treated with radiotherapy, five in patients treated with surgery, and one in a patient treated with surgery and radiotherapy. These results indicate that after induction chemotherapy conservative surgery is possible in almost all cases of Ewing's sarcoma of the extremities and that such treatment is better than radiotherapy alone as local therapy.

Adolescent↗
PubMed1988

Resection of the proximal humerus and I.O.R. modular prosthesis in the treatment of metastatic lesions.

The authors report a series of 20 patients affected with metastatic lesions of the proximal humerus (19 cases) or scapula (one case) treated by intra-or extra-articular resection of the humerus and successive reconstruction with an I.O.R. type shoulder modular prosthesis. This method is indicated for the treatment of patients with extensive destruction of the epiphysis and cortical bone and limited invasion of the surrounding soft tissues. Prosthetic implant does not contraindicate the use of postoperative radiotherapy, and the cement used to anchor the endomedullary shaft contributes to the sterilization of any metastatic microfoces present by means of an intense esothermic polymerization reaction. The results obtained were satisfactory, with regression of pain and good functional recovery of the limb. There were no postoperative complications.

Adult↗
PubMed1988

Neoadjuvant chemotherapy in the treatment of osteosarcoma of the extremities: preliminary results in 131 cases treated preoperatively with methotrexate and cisdiamminoplatinum.

The results of 131 cases of classic non-metastatic osteosarcoma of the extremities treated with preoperative chemotherapy, surgery and postoperative chemotherapy are reported. Preoperatively, the patients were given Methotrexate (MTX) intravenously (high and average doses) and Cisplatinum (CDP) intraarterially. For postoperative chemotherapy, the drugs and treatment protocols were based on the degree of necrosis observed (good, fair, poor). Conservative surgery was performed in 73% of the cases and amputation in 27%. At an average 30 month follow-up (9-48 months) 59.5% of the patients had remained disease-free, 37.5% had developed metastases, and 3% had developed local recurrence. The percentage of disease-free patients was higher for those treated with high doses of MTX (68% vs. 51%) and for those in whom preoperative chemotherapy had induced good necrosis (75% vs. 44%). Neither the age or sex of the patients, nor the site of the tumor or type of surgery performed influenced prognosis.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

Dedifferentiated chondrosarcoma.

The cases of forty-six patients who had dedifferentiated chondrosarcoma were reviewed. Two groups were identified: one in which a low-grade malignant chondrosarcoma was the precursor lesion and one in which a moderate to high-grade malignant chondrosarcoma was the precursor lesion. The radiographic features of these lesions ranged from that of a cartilaginous lesion that appeared to be benign to that of a destructive osteolytic tumor in which the cartilaginous component was overshadowed by the dedifferentiated component. Only three of the forty-six patients survived for more than two years. Resection alone, even when it was wide or radical, was not successful in controlling this lethal sarcoma.

Adult↗
PubMed1987

A study of the bone-cement interface in upper limb prostheses not subjected to loading.

The appearance of a radiolucent band at the cement-bone interface is a frequent finding in lower limb prostheses. This is still a controversial subject, but almost certainly has a multifactorial basis. Stress related to loading may be one of the causal factors. The authors therefore studied the evolution and behaviour of this radiolucent line at the bone-cement interface in 31 upper limb prostheses not subjected to significant loading or stress. These were special prostheses designed to replace the upper humerus after the radical excision of bone tumours. The development of a radiolucent band was not significantly different from the usual conditions in which loading is present but in our cases it was nonprogressive and there was never any evidence of loosening of the prosthesis.

Adult↗
PubMed1986

[Radiographic aspects of metastasis to the foot].

The authors present the radiographical features in 8 cases with metastatic tumors to the foot bones. Seven of them have been histologically confirmed. In 4 cases the tumor was monostotic and mainly osteolytic. In the other 4 the neoplasia, having osteolytic or osteoblastic appearance, involved multiple contiguous bones.

Aged↗
PubMed1985

Juxtaepiphyseal aneurysmal bone cyst.

Nine cases of aneurysmal bone cyst arising in juxtaepiphyseal locations with gross invasion of the adjacent growth plate are reported. In five of these patients an abnormality of growth, due to premature fusion of the affected growth plate, ultimately developed. Treatment of these lesions should attempt to avoid this complication, which appears to be more common than has been appreciated in the past. These nine cases represent 23% of 39 cases of aneurysmal bone cyst occurring in a long bone adjacent to an open epiphyseal plate. This series was extrapolated from a total of 198 cases of aneurysmal bone cyst in the files of the Istituto Ortopedico Rizzoli, Bologna, Italy.

Adolescent↗
PubMed1985

The importance of the angle of anteversion in the development of arthritis of the hip.

The angle of anteversion, assessed by the Dunlap technique, was determined in 30 patients suffering from primary osteoarthritis of the hip. This was compared with the same angle in 10 normal subjects. The patients with arthritis showed a statistically significant increase in the angle. This is considered by the authors to play a significant part in the pathogenesis of primary osteoarthritis of the hip.

Adult↗
PubMed1984

Domed (cupola) tibial osteotomy in the treatment of decompensated arthrosis secondary to genu varum.

Decompensated arthrosis secondary to genu varum is always a severely disabling condition. In English speaking countries there is an increasing trend towards prosthetic replacement surgery, but the present paper aims to show that valgising tibial osteotomy is still a valid form of treatment. The authors also discuss the various techniques that have been used and describe the advantages and results of their own preferred technique of "domed" osteotomy.

Arthritis↗
PubMed1984

Arthroprosthesis in old unreduced congenital dislocation of the hip, using the "false" acetabulum. A study of 34 cases.

In adult patients with considerable loss of function due to an unreduced congenital dislocation of the hip with a false acetabulum, the authors posed the question "Is it feasible, with a reasonable chance of success, to perform an arthroprosthesis in the "pathological" position, using the false acetabulum as a seating for the cup?" The aim of this study was to assess, in particular, the holding properties of the cup which has to be fitted after appropriate reaming, into this rather precarious false acetabulum. They define the indications for this procedure and describe their technique. The results of 34 operations, followed up for an average of 5 years, confirm the validity of this procedure.

Acetabulum↗
PubMed1984

Intertrochanteric osteotomy in the treatment of idiopathic osteonecrosis of the head of the femur in adults. A study of 76 cases with a follow-up of 3-16 years.

This study is an evaluation of intertrochanteric osteotomy in cases of idiopathic osteonecrosis of the femoral head (I.O.F.H.) in patients too young to be suitable for prosthetic replacement. The variety of material, the length of follow-up, and the detailed evaluation on a points system, are sufficient for valid comparison with more recently introduced methods of treatment.

Adult↗
PubMed1983

Composite acrylic cement with added hydroxyapatite: a study of the polymerization temperature.

Varying percentages (0 to 50%) of crystalline hydroxyapatite (HA) in powder form were added to ordinary acrylic cement (PMMA). The exothermic peak of the polymerization reaction and the setting time of this compound cement were investigated. Its mechanical properties are far superior to those of ordinary cement. The addition of small percentages of HA to acrylic cement produces a sharp fall in the exothermic polymerization peak; it also increases the setting time, although this remains within time limits that are only slightly greater than those for ordinary cement.

Bone Cements↗