In order to understand the role and efficacy of vascularized fibular graft and massive allograft in reconstruction of the knee, we have analyzed and review 25 patients of primary malignant bone tumours within 5 cm around the knee, that were managed primarily by this technique. In 4 patients the distal femur was affected while the proximal tibia was affected in 21 patients. There were 16 male and 9 female with an average age at the time of surgery of 19.7 years (range; 5 to 52), 17 patients (68%) were skeletally immature. The pathology was mostly represented by Osteosarcoma and Ewing sarcoma (15) and 18 patients (72%) received pre-operative chemotherapy. The resection of the tumor was transepiphyseal in 13 patients (52%) and intercalary in 12 patients (48%). The method of reconstruction was mainly concentric (allograft and fibula inside in 22 patients, 88%), while fixation was done principally by diaphyseal plate and metaphyseal screws (14 patients, 56%). Only three flaps failed (12%) detected by postoperative bone scan and confirmed by the clinical follow up. Twelve patients (48%) had 17 local complications (68%). Management of these complications succeeded to control them in nine patients (75%). The average time of union of fibula was 5.6 month (range: 3–10). The average time of union of allograft was 19.6 month (range: 10–34). All allograft united primarily (92%) except two cases; one case required bone graft and re-platting at 13 month postoperative after implant failure to achieve union 2 months later ; the other had infected non-union of allograft and amputation was done. Functional results were evaluated using the modified 30-points Musculoskeletal Tumor Society rating score (MTSRS) at final follow up of average 143 month (range; 28–213): the average total score was 27.4 (range; 18 to 30). All patients had good functional range of motion of the knee with stable knee at final follow up and were able to perform sport. Long term results of this study clearly indicates that allograft and vascularized fibular graft is a useful limb salvage procedure providing a biological long-term solution especially in skeletally immature. This technique provides single stage life long reconstruction. The allograft shell provide early stability and fixation to support a small epiphyseal fragment to preserve the articular surface and the vascularized fibula provides revascularization and osteointgration with the allograft to finally offer a long lasting durable reconstruction with full rang of motion of the knee.

Aims: Collagen implants are used for repair of chondral defects. We investigated the behavior of human chondrocytes of either healthy or osteoarthritic joints and ovine chondrocytes and bone marrow stromal cells seeded in a collagen-GAG copolymer matrix comprising collagen type I, II and III. Methods: Cells were seeded on matrices and cultured for 12 hours, 4 days, 1 week, 2, 3, and 4 weeks. We evaluated morphology and biosynthetic activity of the cells by histological analysis, immunhistochemistry, electron microscopy, biochemical assays for glycosaminoglycans and DNA, and expression of collagens by RT-PCR. Results: From 12 h to 3 weeks the histology showed a increasing number of spherical cells, consistent with chondrocytic morphology except in the osteoarthritic-chondrocyte-seeded scaffolds. GAG analysis showed an increasing amount in all cell-types except osteoarthritic ones. Human chondro-cytes from healthy cartilage increased the amount from 0 μg/mg GAG at 12 hours to 0,9 μg/mg at 2 weeks. Ovine bone marrow stromal cells from 0,5 μg/mg GAG at 12 hours to 2,9 μg/mg at 4 weeks. Conclusions: The collagen trilayer matrix may be of value as a vehicle for chondro-cyte implantation harvested from healthy cartilage. This matrix also supports the expression of chondrocytic proteins in ovine bone marrow stromal cells without use of growth factors. However, chondrocytes from osteoarthritic cartilage revealed low bioactivity and can not be recommended for cell transplantation procedures.

The main weakness of the classical external þxator is the penetration of the bone, this conducting to the entrance of the pathogenic germs by their migration toward the pins.

Despite the fact that the centromedullary synthesis is done after several weeks after the removal of the external þxator the risk of infection after the operation remains signiþcantly high. Considering these theoretical assumptions and experiencing in our current practice such complications we have started to use 3 years ago the pinless external þxator for the stabilization of the tibia fractures.

Between 1999–2002 there were hospitalized and operated 213 patients with open tibia fractures, 28 being treated using the pinless external þxator.

From those cases PEF was used for 9 patients with type II lesions, 8 patients with type IIIA lesions and 3 patients with type IIIB lesions.

After resolving the soft tissue injuries (approx. 2 weeks) the external stabilization was converted to internal centromedullar solid stabilization, without the risks associated with the use of the classical external þxator.

Our conclusion was that the external pinless þxator is less invasive, stable and realize a good adherence to the bone. This guarantees the centromedullary conversion of the osteosynthesis with minimal risks, as it doesnñt expose the medullar cavity of the shaft.

Aims: The technique of microfracture for the arthroscopic treatment of articular cartilage (AC) defects has been shown to result in reparative tissue in the defect, however, retrieved tissues have demonstrated þbrocartilagenous material. The objective of this study was to evaluate the tissue types formed in AC defects in an ovine model treated by microfracture with a collagen- GAG-copolymer trilayer matrix consisting of collagen type I, II and III and autologous cultured cells. Methods: Sixteen adult sheep were used in the study following the protocol accepted by the Animal Care Commitee of the University. Two 4.5-mm diameter defects were produced in the medial condyle of the right knee, all AC was removed without penetrating the subchondral bone. In twelve animals microfracture was performed with a curved pick, in four of them without further treatment, in four the defect was covered by the collagen implant alone, and in four by the cell-seeded implant with cultured autologous chondrocytes from the left knee, 4 defects served as controls. After four months the knees were removed, parafþn sections were stained with H & E, Safranin O/fast green, alcian blue, azan, and antibodies to types I and II collagen. Results: All treatment groups showed better þlling of the defects than untreated knees. Histological analysis revealed the biggest amount of hyaline-like tissue in the cell augmented treatment group. Reparative tissue was predominantly þbrocartilage in the other groups. Conclusions: Collagen implants are able to increase the repair of chondral defects in combination with microfracture.