抄録
Masquelet technique has been widely used in bone repair, especially in large-sized bone defects because the two-stage surgery can induce a membrane around the defect, which can not only protect and support the defective tissues, but also secret growth factors required for healing. As mentioned above, a typical Masquelet technique consists of two stages. First, bone cement, mainly composed of polymethyl methacrylate, is implanted into the bone defect site to induce a tissue membrane around the material. Next, the bone cement is removed without removing the tissue membrane, and some bone substitute is placed into the tissue membrane to reconstruct the bone defect. However, the state of the induced membrane largely influences the success of the surgery, that is, when the membrane is suitable for bone substitute implantation. The aim of this study is to investigate the peak of induced membrane on secreting growth factors in different age groups. To achieve this goal, rats aged at 4 weeks, 8 weeks, 12 weeks and 16 weeks were established critical size bone defects and induced membrane formation on their femurs, as the first-stage surgery in Masquelet technique. The induced membranes were harvested for each group of rats at 2, 4, 6 and 8 weeks postoperatively. The condition of induced membrane on secreting growth factors in different age groups was investigated by examining genes and proteins related to osteogenesis. As a result, regardless of age, both vascular endothelial growth factor A (VEGF-A) and transforming growth factor beta (TGF-β) presented peak values at 2-4 weeks, while the peak value of bone morphogenetic protein 2 (BMP-2) appeared at 4-6 weeks. In conclusion, the osteogenic and angiogenic properties of the induced membranes were best at 2-6 weeks, especially at the fourth week. The age around sexual maturity seemed not affect the trend much.
Key words: Masquelet technique, bone, regeneration, reconstruction, gene expression, VEGF, TGF-, BMP
