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Biomedical subjects

G Masetti

Publications and source records attributed to G Masetti.

17 recordsLinked to original sources
PubMed1999

New composites of hydroxyapatite and bioresorbable macromolecular material.

Composite materials were prepared by mixing in different proportions of hydroxyapatite (HA) and poly(epsilon-caprolactone-oxyethylene-epsilon-caprolactone) block copolymer (PCL-POE-PCL) to produce a new resorbable material for biomedical applications. This material has proved to be very interesting for production of periodontal membranes. Mechanical properties are linearly proportional to the amount of HA introduced. Fourier transform infrared (FTIR) investigations have pointed out that HA is able to influence some close epsilon-caprolactone molecules to start its homopolymerization giving PCL with an end chain ionic bonding. HA grains are therefore surrounded by a film of PCL which grants close connection of HA grains within copolymeric matrix. This interface bond with PCL is, however, an interesting occurrence for preparations of HA/PCL composites.

Journal Article↗
PubMed1978

Interilioabdominal amputation.

Thirty two consecutive cases of interilioabdominal amputation are reported. They were performed for malignant tumours of the hip and the proximal end of the femur and thigh. This operation is rather more frequently indicated than disarticulation of the hip and involves less trauma.

Amputation, Surgical↗
PubMedDate not supplied

Considerations on ceramic prosthesis explants.

The authors report data obtained for 11 cases of explants of prostheses having ceramic joint surfaces. The wear phenomena observed in 9 prostheses, including 1 case with breakage of the ceramic head, was moderate: 20-22,000 debris per mu 2. In 2 cases the wear was massive, with a concentration of debris in the peri-implant tissues 5-10 times greater (100,000-218,000 debris per mu 2). An explanation for the trigger mechanism of wear phenomena is proposed: the cases of massive wear are related to loosening of the acetabulum. A histological examination of the bone tissue surrounding a stem covered with alumina (Al2O3) carried out in three cases allowed us to observe an area of demineralization measuring approximately 500 mu of tissue in contact with the ceramic coating. The osteomalacia could be caused by the diffusion of alumina ions.

Bone Cements↗
PubMedDate not supplied

Osteosynthesis in fractures of the femoral neck in the young adult.

The authors report 21 cases of fracture of the femoral neck in the young adult followed-up after a minimum of 2 years, which is a sufficient amount of time to be able to evaluate cephalic necrosis. The results obtained with the various methods of osteosynthesis were: excellent: 38%; good: 33.5%; fair: 9.5%; poor: 19%. Emphasis is made on the effectiveness of the Garden classification system for prognosis and treatment, and several aspects of the method used are discussed.

Adolescent↗
PubMedDate not supplied

The Ilizarov method for the treatment of non-union in the humerus.

The authors report 7 cases of septic and aseptic pseudoarthrosis in the humerus, with or without tissue loss, treated with the Ilizarov apparatus. The method proved to be therapeutically effective, guaranteeing a short amount of time required for consolidation, with bone callus of the periosteal type which was abundant and mechanically effective, immediate functional recovery, and no important complications.

Biomechanical Phenomena↗
PubMedDate not supplied

Indications and limits of acetabular reimplantations using screwed prostheses.

The clinical and radiographic results of 95 acetabular reimplantations performed between 1984 and 1992 are presented. A screwed acetabular prosthesis was used in 56 patients, the acetabulum was cemented in 15, and a press-fit acetabulum stabilized by screws (1 case without screws) was used in 24. Mean clinical follow-up was 35.6 +/- 24 months, ranging from 7 to 94 months. Clinical results were good and excellent (> or = 5 points according to Merle D'Aubigné) in 77% of the cases for pain, in 70% for walking, and in 71% for joint movement. Forty months after surgery 48% of the screwed acetabula and 44% of the cemented ones were osteointegrated. The incidence of loosening for the screwed acetabula was 24%. The preliminary results 24 months after the press-fit acetabula with screws had been inserted showed 100% osteointegration. Radiographic results of the screwed acetabula were satisfactory (92% osteointegration) only in reimplantations performed in patients with minimum acetabular osteolytic injury (Paprosky types I and IIA). The use of homoplastic bone grafts did not improve the radiographic results of the screwed acetabula in the cases with severe osteolysis: 57% of the acetabula screwed on grafts distributed throughout the acetabulum were, in fact, loosened.

Acetabulum↗