Autologous bone marrow derived mononuclear cells combined with ß-tricalcium phosphate and absorbable atelocollagen for a treatment of aneurysmal bone cyst of the humerus in child.

Aneurysmal bone cyst is a benign, locally destructive lesion of bone. Based on progressive cortical thinning pathological fractures are common, and are often the presenting feature. Despite the long experience of orthopaedists, radiologists and pathologists with aneurysmal bone cyst there is limited knowledge regarding the cause of the lesion and optimal treatment. Common methods of treatment vary considerably in the literature, particularly in children. A large variety of bone substitutes have been used to fill the cystic lesions. To date there has been no graft material which can be regarded as completely satisfactory. Our experience with freshly isolated autologous bone marrow derived mononuclear cells combined with ß-tricalcium phosphate and absorbable atelocollagen for bone formation is presented. The concept of this treatment is based on stimulation of natural events continuously present in living bone appear to be a reasonable and beneficial alternative to promote healing of bone cysts and offering both osteoinduction and osteoconductive features.

Treatment of tibial bone defect with rotational vascular periosteal graft in rabbits.

It is well known that the periosteum is capable of bone formation. In the present study, the value of the vascularized periosteal graft in healing the long-bone defect filled with the allogenous bone graft was studied. The aim of the study was to verify the efficiency of the rotational vascularized periosteal graft as a optional surgical method as well as to prove its advantages in comparison with the nonvascularized periosteal graft. The study was undertaken on 40 rabbits. Four rabbits served as allogenous bone graft donors, while the remaining 36 were divided into two equal groups. In the control group, the experimentally created bone defect on the junction of the tibial proximal and median thirds was filled with allogenous bone graft and then covered with avascular periosteal graft. In the experimental group, the allogenous bone graft filled defect was covered with the rotational vascular periosteal graft. Groups of 6 rabbits from each group were sacrificed after 2, 5 and 12 weeks following surgery. The results were evaluated with radiographical, histological and morphometric methods. The results obtained 2 and 5 weeks after surgery demonstrated better tibial bone defect healing in the experimental group. The defect was bridged in both analysed groups after 5 weeks and was completed after 12 weeks with no difference between the control and the experimental groups. The obtained results have confirmed the efficiency of the method using the rotational vascularized periosteal graft in the treatment of tibial bone defect in rabbits. The advantage of the vascularized periosteal graft as compared to the avascular one has been proved by better quality of bone healing in the early stage.

Intra-articular calcaneal fracture in a 14-year-old competing skier: case report.

Intra-articular calcaneal fracture as a skiing injury in children is extremely rare. We report on what we believe is a unique and previously unreported mechanism of a skiing injury, which caused intra-articular calcaneal fracture in a young competing skier, a member of the Croatian national ski team. This 14-year-old boy sustained a heel injury while training for giant slalom. There was no fall on the heel or obvious axial force that could have caused this type of calcaneal fracture. The skier had sophisticated equipment and used carving skies. We speculated that, when the skier tried to establish the lost balance during the fall, a violent contraction of triceps muscle occurred. Instead of an injury of a well-protected tuber or Achilles tendon, the strong pulling force of the Achilles tendon was transmitted more distally and anteriorly, generating axial compression force, which caused an intra-articular fracture of the calcaneus bone. Obviously, the existing ski boot did not sufficiently protect the calcaneus bone. We postulate that the calcaneal tuber and Achilles tendon were protected on the expense of the intra-articular calcaneal fracture. Our case warns of the possibility of a serious foot injury in young top skiers in spite of extensive improvement in the ski equipment. Sophisticated carving skis could be a contributing factor to an injury.

Systemic and local expression of perforin in lymphocyte subsets in acute and chronic rheumatoid arthritis.

OBJECTIVE: To investigate the role of the cytolytic action mediated by perforin in the course of rheumatoid arthritis (RA), we studied the immunophenotypic characteristics of lymphocytes containing perforin in peripheral blood (systemic level), in synovial fluid (SF), and in the synovial membrane (local level) in patients during the acute or chronic phase of RA. Cells from patients with osteoarthritis were used as controls. METHODS: Flow cytometry was used for simultaneous detection of intracellular (perforin) and cell surface antigens. Mean fluorescence intensity (MFI) was a measure of the mean perforin content per cell. Immunocytochemical staining was used to visualize perforin in the cytoplasmic compartment of cells. RESULTS: In acute RA highly significant changes in perforin expression were found in all compartments (peripheral blood, SF, and synovial membrane): (1) increase of percentage of total perforin positive cells; (2) increase of both subsets of cytolytic cells, T (CD8+P+) and NK (CD56+P+) cells; (3) increase in the frequency of perforin positive cells in CD8+ and CD56+ cell populations; and (4) the highest content of perforin/cell (MFI values) in all compartments, except in the synovial membrane. CONCLUSION: Perforin positive cells may participate in the acute phase of RA by maintaining and perpetuating inflammation and contributing to tissue destruction.