The choice to use alumina in the manufacture of a low-wear THR bearing made by Boutin and its co-workers has proven its effectiveness in almost 35 years of clinical use. A continuous development process aimed to improve mechanical properties led to today’s materials that exhibit extreme high reliability.

The recent introduction in clinical use of alumina matrix composites represents the latest evolution of alumina that thanks to high hardness, toughness, and bending strength allow to manufacture new design of ceramic components. Composites obtained introducing zirconia in the alumina matrix, known as Zirconia Toughened Alumina (ZTA) are candidate for use in THA bearings from a long time. A real breakthrough was represented by alumina ceramics toughened both by zirconia both by platelets nucleated in-situ during sintering (Zirconia-Platelet Toughened Alumina - ZPTA).

The chemical composition and the microstructure of ZPTA were optimised to achieve a ceramic material joining strength of more than 1200MPa, Vickers hardness 1975, fracture toughness of 6,5 MPa m-1/2, andextremely low wear also in the most severe simulator tests performed in microseparation mode The paper reviews the improvements introduced in the technology of ceramic for arthoplasty, and their effects on the microstructural properties and on the performances of the past and actual generation of ceramic for THR bearings, and summarise the results obtained in the development of alumina matrix composites.

Primitive malignant neoplasms affecting the distal third of the tibia are altogether rare. The authors describe the diagnostic procedure and surgical strategy of limb salvage in a case of malignant fibrous histiocytoma in this region, in a 50-year-old male. In this anatomic region, considering the limb salvage surgery, there are different reconstructive possibilities, as ankle prosthesis and arthrodesis with or without vascolarized fibula. The Authors underline the infective and mechanic problems of these surgical solutions, proposing a different arthrodesis. The surgical treatment consisted in resection of the distal third of the tibia and fibula. The restoration of the skeletal continuity has been obtained by a locked nail. The mechanical resistance of the system has been obtained by acrylic cement. A vascularized myocutaneous flap allowed the cover of the resection area. About 28 months after surgical intervention, the patient is now able to walk without the aid of the knee stabilizer nor the sticks; without signs of local recurrence of the disease, metastases, with no implant failure, nor of the cement. The very favourable outcome of the clinical case previously described should make this method be looked at as one of the available surgical options in treating these lesions.

It is well known that wide resection and reconstruction with modular or composite prostheses is the treatment of choice in high chondrosarcoma of metasepiphyseal bone. Nevertheless there is a debate concerning the treatment of low grade chondrosarcoma, a locally aggressive tumour, similar also histologically to benign lesion. Two different therapeutic options are reported in these lesions: wide resection and intralesion curettage. Between 1995 and 2003 the Authors analysed a series of 37 cases of low grade chondrosarcoma of long bone treated with curettage and local adjuvant, like liquid nitrogen and acrylic cement, if necessary associated with synthesis. The least follow-up was two years. The authors observed 3 local recurrences within the first 12 months from the surgical treatment; and, in every case, an increased grade of malignity was observed at histology. The Authors confirmed that the aggressive intralesional treatment with the use of the local adjuvant like liquid nitrogen and cement, is a valid therapeutic possibility in these lesions, but they confirm that it’s necessary an accurate preoperative diagnosis with also open biopsy for an efficacy treatment.

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.

Pain is the main symptom of acetabular osteolysis and is frequently associated with pathologic fractures. Surgical procedures requiring an aggressive approach, and as a consequence high morbidity, are rarely indicated. The minimally invasive approach may be effective in treating tumours and is capable of reducing the mechanical pain. PMMA has been widely used in neoplastic and spinal surgery as a bone filler because of its mechanical and biologic behaviours. Recently percutaneous injection of PMMA was proposed for the treatment of neoplastic acetabular osteolysis.

The technique was tested in four patients affected by secondary ostheolytic lesions. The patients were evaluated clinically (HHS, Womac, SF-12) and radiographically (X-ray and CT) at 18 months.

All the patients demonstrated a durable and significant improvement in terms of pain and restoration of function. The radiographic examinations (X-ray and CT) confirm these results. Complications (temporary increase in pain and fever) were only observed in one patient.

The preliminary results demonstrate the reliability and effectiveness of this procedure. Clinical results showed a significant reduction in pain and the capability of restoring function. The indications can be extended also to the acetabular lesion at a distance from the weight-bearing zone, reducing pain and the risk of pathologic fractures.

The technique was demonstrated to be effective and showed only minor and self-resolving complications. It is useful in patients in whom major surgery is contraindicated and clinical improvement is necessary to improve the quality of life.

Aims: Yttria-stabilised Zirconia (Y-TZP) ball heads were introduced into the market in 1985. Since then these components have had wide diffusion in hip replacements, due to their good mechanical performance and reliability. Namely, only a few papers were published up to now reporting failures of Y-TZP ball heads. The worldwide recall in August 2001 of some Y-TZP batches changed this situation. The recall was due to an high number of fractures, that were somehow linked to the spontaneous phase transition in Y-TZP. The revision surgery of a zirconia head belonging to the batches in above that fractured 34 months after implant gave us the opportunity to retrieve the fragments for analysis, and to draw some conclusions about the cascade of events that led to the ball head fracture.

Methods: The retrieved specimens were submitted to visual inspection by optical microscopy to analyze the fracture pattern, then selected samples were cut and analysed by FEG-SEM equipped with backscattered CEN-TAURUSA8 detector. Specimen were analysed without any coating. Grain size were measured by SEM-coupled computerized image analysis on thermally etched samples. Phase composition was investigated by XRD. Density was determined by the Archimedes’ method. Periprosthetic tissue membrane collected at revision surgery was observed by light and Scanning Electron Microscopy coupled with EDAX.

Results: XRD showed that maximum of about 60% monoclinic phase was present in the inner cone near the chamfer, while in the outer polished surface only 3% monoclinic phase was present. SEM demonstrated that the zone near to the surface of the taper, in the core of the ball head, consisted of an inhomogeneous structure formed by dense agglomerates of Y-TZP grains, about 10 mm in diameter, within a matrix of lower density. A crack network originated from the above mentioned inhomogeneous zone, and extended through the outer part of the sample which consists of well densified material. Histologic sections showed the presence of many metal particles in a poor in vessels stroma; ceramic appeared as polygonal shape granules of different dimension, ranging from 2 to 10 B5m.

Conclusions: The Authors demonstrated that the likely initiator of the failure is to be sought in subcritical crack growth of the defects due the uncontrolled densification during sintering, enhanced by the wet environment and by cyclic loading. The hydrothermal stability of the material had only a secondary role in the fracture.

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.

We studied factors contributing to the initiation of fracture and failure of a zirconia ceramic femoral head. The materials retrieved during a revision total hip replacement were submitted to either visual, stereomicroscopic and scanning electron microscopy (SEM) or SEM and energy-dispersive x-ray analysis. X-ray diffraction was performed in order to investigate the extent of tetragonal to monoclinic phase transition. Histological examination was performed on the periprosthetic tissues.

The results showed that failure was due to the propagation during clinical use of defects which may have been introduced into the material during the processing of the ceramic, rather than those intrinsic to zirconia. The literature relating to previous failures of zirconia components is reviewed.

Aims: Primary non-Hodgkin lymphoma of bone account for 5% of extra nodal lymphomas. The Authors report their experience referring to the results obtained with a multidisciplinary approach.

Materials: 18 cases of lymphoma of bone were included. Medium age was 63 yrs. All cases have been classified according to the REAL classification system. Patients have been staged with: total body CT scan, bone marrow aspirate, bone marrow biopsy, LDH serum level, skeletal survey and MRI of the skeletal segments involved. We treated 10 cases with solitary localization and 8 with multiple ones. Three patients presented with a pathologic fracture at diagnosis.

Chemotherapy protocols were:

MACOP-B < 60 yrs.

VNCOP-B > 60 yrs.

Seven patients received the PROMACE-CYTABOM protocol.

13 patients received EBRT (40 Gy). Ten patients received a surgical treatment: internal fixation in 7 cases and of spine stabilization in 3 cases

Results: At a medium follow-up of 40 months overall survival was 34,6 months and 14,5 months respectively for solitary or multiple localizations. Surgical treatment has been useful in improving performance status and in some cases to obtain a better control of the disease.

Discussion: In our experience bone lymphomas have always a high grade histology. Chemotherapy constitutes the treatment of choice. Surgical treatment have to be considered as a support treatment. Prognosis is worse in multiple localizations

An increased long-term survival of patients with malignant tumours also increases the possibility of the development of skeletal metastases and pathological fractures. The management of bone metastases includes the removal of gross disease and the administration of local adjuvants. We have investigated the possibility of adding antiblastic drugs to acrylic cement.

Cylinders of acrylic cement were manufactured containing three different antiblastic drugs, methotrexate, cisplatin and doxorubicin.

We performed in vitro analysis on MCF-7 human breast cancer cells in order to evaluate the biological effect of the mixtures and surface analysis of the acrylic cement-cisplatin cylinders using energy-dispersive x-ray analysis (EDAX). All drugs were released in an active form from the cement. Each drug had a different effect on cell viability. Doxorubicin had the greatest effect on breast cancer cells. Surface analysis showed that antiblastic drugs were present in the form of granules.

These results confirm the potential of antiblastic-loaded cement as a possible adjuvant in the local treatment of bone metastases.

Further studies should be undertaken to determine whether the release of antiblastic drugs from cement is elution or if they are only released from the surface.