Aim. Ceramic-ceramic coupling is currently used in Orthopaedics in younger patients with longer life expectance, for the high biocompatibility of these materials. More recently new ceramic materials have been developed with better mechanical properties in comparison to Alumina, as the Alumina Matrix Composites by Transformation Toughened and in situ Plateled Reinforcement (ZPTA). The aim of the study was to analyze the biological properties of this material in comparison to Alumina and Zirconia. Materials and methods. Cylinders of different ceramic materials were inserted into surgical created defect of proximal metaepiphysis of New Zealand White adult rabbits to analyze the bone response to ceramics. Percentage of bone ceramic contact was measured. Massive inflammatory response was analyzed by intraarticullar injection of powders of different materials; while chronic low grade response as the one observed in long term well functioning implants was tested by implantation of low cohesive ceramic pellets under patellar tendons of rabbits: thank to leg movements few particles were released in time. Systemic host response was tested analyzing peripheral organs of animals. Results. Connective tissue was present at bone ceramic interface whatever materials used: no statically differences were observed in term of bone ceramic contact among Alumina, Zirconia and ZPTA. Inflammatory response with new vessels was observed around powders, especially with small diameter; while low cohesive pellets did not elicited inflammatory response neither systemic toxicity. Discussion and conclusion. Our results confirm that Alumina Matrix Composites by Transformation Toughened and in situ Plateled Reinforcement, as well as Alumina and Zirconia ceramics, induces a low inflammatory reaction in periprosthetic tissues without any systemic toxicity, due to massive or chronic release. So thank to its higher mechanical properties than Alumina and Zirconia, it should be indicated for ceramic to ceramic coupling in Orthopaedic Surgery.

Aims: PMMA is currently used as grouting agent of arthroprostheses and for filling of bone cavities after bone curettage. It is moreover used as a carrier of antibiotics in the local treatment of bone infections and it has been proposed as a carrier of antiblastic drugs in the local treatment of bone metastases. The aim of this study is to analyse the biological properties and compressive strenght of PMMA-Methotrexate mixture to be used for the local treatment of bone metastases.

Methods: Cylinders of PMMA containing Methotrexate in different concentrations were manufactured according to ASTM F-451. Cylinders of PMMA were used as control. The porosity of the cylinders was characterised by SEM. Drug elution rate in saline solution was measured by HPLC. The biological activity of Methotrexate was analysed on human breast cancer cells using MTT test at different time (from 5 minutes to 30 days). Compressive tests was performed in conformity to ASTM F-451 on PMMA- Methotrexate samples and control as-made and after 30 days of aging in saline

Results: SEM analysis showed the presence of granules of Methotrexate on the surface of as-made cylinders that can be readily released from PMMA cylinders. The release occurred in large amount within 24 hours after immersion. We observed a relative release rate is more sustained in samples containing the drug in lower concentration. Also the biological activity was time dependent: cell death decreased progressively from 60% at 24 hours to 10% at 30 days.

Compressive tests showed no statistical differences between PMMA cylinders containing Methotrexate and controls before and after aging in saline.

Conclusions: The results show that PMMA-Metho-trexate may be considered an interesting option in the treatment of bone metastases because cement allows mechanical resistance after bone curettage or resection and Methotrexate improves locally anticancer activity.

In primary malignant bone tumours, the “en – block” excision with the sacrifice of soft tissues causes a functional deficit of the interested limb. There are many possibilities for reconstruction after a wide resection of the proximal humerus. The Authors report their experience using megaprostheses, focusing to soft tissue reconstruction, in order to obtain a good and fast functional recovery of the involved limb. 13 megaprostheses of the proximal humerus were employed. All patients were affected of primary malignant bone tumors with different histology. The tumor was staged according to Enneking’s system. 8 cases were classified as IIB and the remaining as IIA. All the tumors were treated with an intrarticular resection. Soft tissues reconstruction was performed, in 8 cases, using a mesh (Trevira tube), dressed all along the prosthesis, with a high resistance to traction. Radio and/or chemotherapy were employed referring to the histology.

At a medium follow – up of two years, for the surviving patients, we have obtained excellent functional results in 1 case, good in seven cases, fair in three cases and poor in two cases. The size of the resection is a main factor in order to obtain a good functional recovery of the joint motion. A wide excision (below deltoid insertion) with the sacrifice of large muscular masses and of the osteoarticular structures can represent a functional amputation causing the loss of muscles that are important to have an acceptable joint movement.

In our experience we retain that the use of modular prostheses in reconstructive orthopaedic surgery is advantageous because of its versatility and of its quick implantation, despite of other reconstructive systems. Moreover the use of a device, as that described, for an easy anchorage of the myotendinous structures, allows a quick functional recovery offering the patients considerable advantages for their social life.