Bone allografts can be used in any kind of surgery involving bone from minor defects to major bone loss after tumour resection. This review describes the various types of bone grafts and the current knowledge on bone allografts, from procurement and preparation to implantation. The surgical conditions for optimising the incorporation of bone are outlined, and surgeon expectations from a bone allograft discussed.
Adiponectin (ApN) is an adipocytokine that plays a fundamental role in energy homeostasis and counteracting inflammation. We examined whether ApN could be induced in a nonadipose tissue, the skeletal muscle, in vivo, and in cultured myotubes in response to lipopolysaccharides or proinflammatory cytokines. We next explored the underlying mechanisms. In vivo, injection of lipopolysaccharides to mice caused, after 24 h, an approximately 10-fold rise in ApN mRNA abundance and a concomitant 70% increase in ApN levels in tibialis anterior muscle. This ApN induction was reproduced in C2C12 myotubes cultured for 48 h with a proinflammatory cytokine combination, interferon-gamma + TNFalpha. This effect occurred in a time- and dose-dependent manner. Several pieces of evidence suggest that nitric oxide (NO) mediates this up-regulation by cytokines in myotubes or muscle. First, ApN was induced in vitro exclusively in the experimental conditions that stimulated NO production. Second, inducible NO synthase mRNA induction or NO production clearly preceded ApN mRNA induction. Third, preventing NO production by inhibitors of the NO synthases, nitro-L-arginine methyl ester or NG-methyl-L-arginine, suppressed the inductive effect of the cytokines in vitro and in vivo. Finally, ApN mRNA induction by cytokines was reproduced in cultured human myotubes. In conclusion, our data provide evidence that adiponectin is up-regulated in vivo and in vitro in human and rodent myotubes in response to inflammatory stimuli. The underlying mechanisms seem to involve a NO-dependent pathway. This overexpression may be viewed as a local antiinflammatory protection and a way to deliver extra energy supplies during inflammation.
Background: Reconstruction of the pelvic arch after resection of a malignant pelvic tumor remains a major surgical challenge because of the high rate of associated complications. The purpose of this investigation was to assess the functional outcome and complication rate following treatment with a bone allograft to reconstruct the pelvis. Methods: Twenty-four consecutive patients underwent excision of a malignant pelvic bone tumor and reconstruction with a pelvic bone allograft. The living patients were followed for a minimum of twenty-four months. There were nineteen primary malignant bone tumors, sixteen of which were high-grade sarcomas, and there were five isolated metastases. Patients were examined clinically and radiographically and were assessed functionally with the Musculoskeletal Tumor Society score. Results: The mean age of the patients at the time of the index surgery was thirty-four years, and the mean duration of follow-up was forty-one months. Eighteen of the twenty-four resections involved the periacetabular area and were followed by reconstruction either with a hip prosthesis (thirteen) or with an osteochondral allograft alone (five). The six other resections involved the iliac bone. All patients received a massive bone allograft that had been sterilely procured without secondary irradiation. At the time of our last evaluation, eight patients were alive and free of disease. Seven patients had a local recurrence. Neurological deficits were present in six patients, and three had a deep infection. Nonunion of three of the sixteen allografts that could be evaluated was observed. Neither graft fracture nor lysis was observed. Eleven patients underwent surgical revision, with nine of these revisions related to the reconstruction. The average Musculoskeletal Tumor Society score at the time of the latest follow-up was 73% of the maximal possible score. The average score was 82% for the eleven patients with an age of less than twenty years at the time of the index procedure and 65% for the thirteen older patients. Ten patients walked without any assistive device, and five of them had normal function with no or only a slight limp. Conclusions: Pelvic reconstruction after a limb-sparing resection is associated with a high risk of surgical complications and usually should be reserved for patients with a primary bone sarcoma. A pelvic allograft can restore the anatomy and provide good functional results, especially in young patients. Nonunion was the most common allograft-related complication. Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.