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Biomedical subjects

A Giunti

Publications and source records attributed to A Giunti.

At least 19 recordsLinked to original sources

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

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

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

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

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

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

Sarcoma in Paget's disease (11 cases).

Eleven cases of sarcoma in Paget's disease of bone are presented, together with an extensive review of the literature. These neoplasms are rare but not exceptional, and mostly affect male subjects in the seventh decade of life. The sites most frequently affected are the pelvis, femur and humerus. In 30 per cent of cases these neoplasms are multifocal. Radiographically the lesions are nearly always osteolytic. The radiographic diagnosis may, however, be quite difficult, especially in the presence of the severe (but benign) osteolyic lesions that sometimes occur in Paget's disease. Morphologically these tumours are mostly highly polymorphic sarcomas. The cases in this series were diagnosed histologically as osteosarcoma, grade 3 fibrosarcoma, and malignant fibrous histiocytoma; but there are no prognostic differences between the various histological types. The prognosis is very serious, only about 3 per cent of patients surviving for five years from the time of diagnosis. Therapy, unfortunately nearly always palliative, is based on amputation or disarticulation after sections biopsy in cases where the disease is localised to the limbs, and on radiotherapy in cases not amenable to surgery.

Adult

Epiphyseal chondroblastoma (a study of 39 cases).

A fully documented series of thirty nine cases of epiphyseal chondroblastoma is described. This is a remarkable series because of the rarity of this tumour. There is a slight predilection for the male sex. The age most affected is ten to twenty years. The tumour progresses slowly and joint involvement and pain are slight. The commonest site is the proximal epiphysis of the humerus, followed by the epiphyses of the knee. The classical appearances are of a clearly defined area of osteolysis, central or eccentric, with foci of calcification, in the epiphyseal or apophyseal regions, and often transgressing the epiphyseal cartilage. We have never observed involvement of the opposite bone in the affected joint. In four of our thirty nine cases the neoplasm invaded the point and/or soft tissues. The differential diagnosis, especially in localisations at the knee, is with giant cell tumour. The tumour is slow growing and the prognosis is always good. We have never seen malignant transformations or so-called "benign" pulmonary metastases. The few recurrences in this series (five out of thirty nine) were all cured by a second operation. Curettage and grafting is the operation of choice.

Adolescent

Periosteal osteosarcoma. Review of 41 cases, 22 with long-term follow-up.

This study is based on 41 cases of parostesl (or juxta cortical) osteogenic sarcoma, which the authors prefer to define as periosteal osteosarcoma. The clinical features, radiological and histological characteristics are analysed. Treatment and prognosis are discussed. The treatment usually indicated is amputation, but in selected cases radical segmental resection is appropriate. The prognosis is comparatively favourable if the correct surgical treatment is carried out without delay.

Adolescent