[Thoracolumbar fractures]. / Fractures du rachis thoracolombaire.

Thoracolumbar fractures are frequent and the functional outcomes are sometimes severe. This multicentric study, including five medical centers, was performed to evaluate the long-term outcomes of the patients. One hundred and thirty six patients with thoracolumbar fracture (T11 to L2) was evaluated with a minimal follow-up of two years. Every one had a clinical exam with a score of Oswestry and an X-Ray study (before and after treatment and at revision). Most of them presented compression fractures, the most often at L1 level. On X-rays, a gain was noted on the vertebral kyphosis immediately after surgery, but there is a loss of correction over time whatever the treatment. The clinical outcomes for the patients were great, with an Oswestry average score of 6,4. A correlation was noted between this functional score and vertebral kyphosis. So, an anterior column strengthening (isolated or performed during the surgery) could improve these functional outcomes. Moreover, the Thoraco Lumbar Injury Severity Score (TLISS) seems to be a simple organigram to determine the most appropriate treatment of these fractures, with particular attention to the distraction mechanism or posterior ligamentous complex lesions. However, RMI before surgery is necessary to evaluate these lesions.

[Tibial valgus osteotomy]. / Ostéotomie tibiale de valgisation.

The tibial valgus osteotomy whatever its technique has a survival rate of about 85 % to 10 years, if we consider the reoperation as a criterion of failure, with a confidence index at 78%. The age, weight, sex and functional signs have no impact on the outcome. We have found no evidence in the preoperative radiographic assessment, neither the medial pinch, or varus epiphyseal neither varisant gap, which could be a failure and a reoperation before the tenth year. Good results were observed significantly when there is an over-valgus at least 3 degrees of global axis of the lower limb. This corresponds to a valgus epiphyseal by more than 2 degrees . The substantial reduction in the gap varisant that lowers the overall time varisant below 200 kg cm provides the same positive results. The outcome will depend directly on the accuracy of the calculation of the preoperative correction performed and the quality of surgical achievement. Because of the need for precision, navigation technique appears as reliable, simple which makes it also possible to monitor the front slope and tibial rotation induced. The osteosynthesis must be stable and rigid to avoid postoperative loss of correction.

[What's new in fundamental research: osteogenesis and stem cells]. / Quoi de neuf en recherche fondamental? Ostéogenèse et cellules souches.

Mesenchymal stem cells (MSC) are progenitors of osteoblasts, chondrocytes and adipocytes. They are in the bone marrow at the concentration of 1 to 104 at 105 mononucleated cells. There is not specific marker to select them. They can be cultured and differentiated in osteoblats or chondrocytes. They induced osteoformation in autologous bone graft. Therapeutic application includes concentrate of bone marrow or MSC expanded by culture, implanted with or without biomaterials. The implantation of MSC cultured on biomaterial has not been yet published in human. The aim of these technics is to reduce the use of bone graft. The first indications for these technics will be pseudarthrosis and bone defect.

[Pertrochanteric fractures in elderly subjects aged over 75]. / Les fractures du massif trochantérien chez les sujets âgés de plus de 75 ans.

Pertrochanteric fractures constitute a major public health concern. This retrospective multicentric study evaluated outcome after treatment in patients aged over 75 years hospitalized for pertrochanteric fractures over a one year period (May 2004-May 2005). Five University Hospitals in the cities of Angers, Brest, Rennes, Tours, Nantes participated in this evaluation. The quality of the reduction and the position of the osteosynthesis were the two main criteria for good outcome. The type of material implanted had little effect on outcome. The results emphasized the importance of preventing osteoporosis. Fracture prevention and treatment of osteoporosis are crucial, even after fracture.

[Surgery and percutaneous injection of acrylic cement in bone metastases]. / Chirurgie et cimentoplastie dans la prise en charge des métastases osseuses.

The first step for treatment of bone metastases is to confirm the diagnosis, particularly if there is only one localisation, so as to exclude a primary bone tumour. Surgery and percutaneous injection of acrylic cement are both efficient to relieve pain. Their indications and timing have to be discussed in pluridisciplinary staff. Long bones metastases have to be nailed before pathologic fracture. If there is suspicion of hypervascularisation, the lesion has to be embolized before any procedure. Treatment of spinal metastases with neurological impairment is an emergency. Paraplegia may be a consequence within a few hours. They have to be treated in an orthopedic or neurosurgery department with the experience of posterior and anterior approach of the spine. Surveillance may be useful to diagnose these metastases before neurological impairment. Depending from the type of cancer, the chemo- and radiotherapy sensibility, the number of metastases, the condition of the posterior wall of the vertebra and the general condition of the patient, different surgical treatments may be possible going from complete resection of the lesion to percutaneous injection of acrylic cement. Conventional radiotherapy is associated to surgery. Satisfactory results of such treatments justify greater involvement of orthopaedic surgery team in multidisciplinary staff.

Enhanced tumor regression and tissue repair when zoledronic acid is combined with ifosfamide in rat osteosarcoma.

The efficacy of zoledronic acid (ZOL), with or without the anticancer drug ifosfamide (IFO), was tested on primary bone tumor growth using a rat-transplantable model of osteosarcoma. The effects on bone remodeling and tumor growth were analyzed by radiography, micro-computed tomography (micro-CT), and histological staining. The in vitro effects of ZOL were studied by proliferation, apoptosis, and cell cycle analyses on the osteosarcoma cells OSRGA compared to rat primary osteoblasts. Treatment with ZOL was effective in preventing the formation of osteolytic lesions that developed in bone sites and in reducing the local tumor growth, as compared to the untreated rats. The combination of ZOL and IFO was more effective than each agent alone in preventing tumor recurrence, improving tissue repair, and increasing bone formation as revealed by the analysis of trabecular architecture. In vitro studies demonstrated that ZOL was more potent against the OSRGA cell line than osteoblasts (with a half-maximal inhibitory effect on proliferation seen at 0.2 and 20 microM, respectively), the ZOL-induced inhibition of OSRGA proliferation being due to cell cycle arrest in S-phase. No effect on OSRGA apoptosis could be observed in vitro, as assessed by Hoechst staining and caspase-1 and -3 activation. In situ cell death was determined by TUNEL staining on tumor tissue sections. No significant difference in TUNEL-positive cells could be observed between ZOL-treated and -untreated rats. This is the first report of the anti-bone resorption and antitumoral activities of zoledronic acid in a rat model of osteosarcoma, and its beneficial association with an antitumoral chemotherapeutic drug in preventing tumor recurrence.

[Assay of IgE specific to dog epithelia by the Pharmacia CAP RAST technique: comparison of the two CAP RAST e2 and e5]. / Dosage des IgE spécifiques aux épithélia de chien par technique CAP Rast Pharmacia: comparaison des deux Cap Rast e2 et e5.

We present a comparative study of measurement of dog-epithelium-specific IgE by two Pharmacia CAP Rast techniques e2 and e5. For both measurements the technique is identical, but the allergen extracts are different: e2 = dachshund extract whilst e5 = a mixture of squames of german shepherd and poodle. We show that the e5-specific IgE seems to be more sensitive than the e2-specific IgE.