Alloys of titanium, aluminium, vanadium, iron and other metals are traditional materials used in bone tissue surgery. The anchorage of the metallic materials into the surrounding tissue depends of their mechanical and other physical and chemical properties. The integration of metallic material with the surrounding tissue can be markedly improved by appropriate physicochemical surface properties of the material, such as roughness, topography, wettability or presence of certain chemical functional groups. In the present study the first step the surface roughness of samples of pure Ti or Ti6Al4V alloy. In order to influence the adhesion, growth and presence of bone differentiation markers in human osteoblast-like MG 63 cells, we modified as machining or subsequent polishing by diamond paste was performed. In addition, we investigated the interaction of these cells with a newly developed material for construction of bone-anchoring parts of bone implants. These tested materials were treated either with electro-erosion or plasma-spraying with Ti. After the cells seeding (MG63, human osteoblast-like cells of the line MG 63, derived from osteosarcoma of a 13-year-old boy, on different surfaces, the basic parametrs of adhesion and the viability of bone cells were detected, the cell were analysed and cultered for 1–8 days, during 3 different time intervals(expl.1. 4. and 7 day). Cells number, were detected and analyzed in a ViCell XR analyzer. The concentration of molecules participating in cell adhesion, osteoblastic differentiation, was determined semi-quantitatively by the enzyme-linked immunosorbent assay (ELISA) in cell. In addition we performed a reconstruction curve of population density of human osteoblast-like MG 63 cells on day 1, 4 and 8. including calculation of doubling time(DT)in human osteoblast-like MG 63 cells grown on metallic materials with different surface treatments. From the tested surfaces Ti Alloys electroerosion surfaces seem promising materials. They show the best osteointegration parameters in vitro. Nevertheles further in vivo experiments must be performed prior to clinical use.

The authors offer their personal experience with long term results on 71 patients (72 allografts) operated between 1961 and 1990. 23 were large osteoarticular grafts, 28 intercalary grafts and 20 fibular grafts. We used one composite hip endoprosthesis in 1988 after 16cm proximal femur resection due to Ewing sarcoma in a 10 year old girl. From the 23 osteoarticular grafts 14 (60%) are long term survivals including one after fracture salvage. Six had to be removed due to infection. From the 28 intercalary grafts 16 (57%) are surviving over 15 years. Infection occurred in 6 patients with chemotherapy. Two of them had intra-arterial CDDP and one additional radiation. All of the proximal humerus allograft had complete resorption of the proximal head within 3 years. The diaphyseal reconstructions with additional cancellous autografts incorporated within 3 years. The patient with the composite stem had two cup revisions, but the stem is doing well and we observed only a mild osteolysis at the proximal part of the graft between the 2nd and 5th year that remains stable. Fractures of the graft can be salvaged in most cases.

Infection leads to the removal of the graft in almost all cases. Factors influencing the survival, remodeling and complications of the grafts are discussed. The regime of cryopreservation, fixation and loading of the graft influence these factors together with the use of autologous bone chips around the allograft-host junction as well as the application of chemotherapy or radiation. Fracture of the graft can be salvaged in most cases in contrary to infection that remains the most severe complication that can occur at any time period. Even with the improvement of tumor endoprostheses the use of allografts remains an optional solution especially in young patients.

Aims: To evaluate the outcome of surgical treatment of benign and aggressive chondroblastoma in the Prague bone tumours register. Methods: Between 1969–2001 57 patients (38 men and 19 women) with chondroblastoma have been registered. The age ranged from 7 to 52 years – in average 19 years. The most frequent localizations were epiphyses of long bones (13 proximal humerus, 10 proximal femur, distal femur and proximal tibia each 11). We also observed atypical localizations (3 patella, 2 pelvis and 1 each in, fibula, talus, 5th metatarsal). All patients had available x-rays for evaluation and some arteriography or CT. All had histological verification. The treatment of choice was intralesional curetting and filling with auto or allografts. The femoral head lesions were treated through an original femoral neck approach to prevent hip luxation. We registered 5 aggressive variants with a different clinical course. They recur after intralesional surgery, are purely osteolytic and richly vascularized. One patient even developed lung metastasis. Results: In the usual type of benign chondroblastoma all patients were healed after intralesional surgery and graft filling with well-preserved function. In the aggressive form we performed a limb saving reconstructive surgery (knee arthrodesis, total knee or hip endoprosthesis). Conclusions: For benign chondroblastoma intra-lesional surgery brings excellent results. The aggressive form should be differentiated and resected at least marginally without delay to prevent larger skeletal defects.