Experimental Research Of Tissue Engineered Bone Cure Ischemic Necrosis Of The Femoral Head

[Objective]:To observe the effect of tissrue engineered bone in the treatment of femoral head necrosis by the animal experiments, to provide a new effective cure for the clinical curative of femoral head necrosis.[Methods]:Choose54adult New Zealand big white rabbit, male and female unlimited, weight (2.0-3.0) kg, bought from Jilin University laboratory animal center. The experimental animal are random numbered, randomly divided into A, B and C three groups according to different surgical methods and18rabbits each group, group A for blank control group (do not do any process), group B for autogenous bone graft group (take autogenous cancellous bone from Ilium, trimming into bone grain then implant down inside femoral head defect), group C for tissue engineering bone group (implant tissue engineering bone of Nano Hydroxyapatite/polylactic acid scaffold into model), and do the marks. After surgery, give penicillin200000U/kg weight daily, muscle injection for a week. Take out stitches of the incision10days after operation, postoperative animal raised in different cage, each group executed animals after4,8,12weeks,6rabbits each time, take the whole bone to reserve. Do the naked eye, X-ray and microscope morphological and histology observation, then statistical analysis the results.[Results]:The application of rabbit bone marrow stromal cells and tissue engineered bone constructed of nanometer hydroxyapatite/polylactic acid implanted in the rabbit avascular necrosis of the bone defect model finished the bone and repair the avascular necrosis of the bone defect after12weeks. Results shown that general macroscopic observation tissue engineered bone wrapped with fibrous tissue, separate difficultly. new blood vessels are significantly increased, surface of the tissue eng ineered bone is smooth, quality is similar with the cortical bone; autogenous bone graft group, autogenous bone graft wrapped with fibrous tissu, more new blood vessels, quality of autogeneous bone surface at the transplant place is harder. Blank control group the apparently fibroplasticproliferation of the avascular necrosis of the bone defect, no repair of bone defect, a small amount of sclerotin formatted at both ends, and gets harder. The observation of Bone mineral density X-ray:12weeks after operation, tissue engineered bone group transplant area has obviously X-ray block, transplant area has similar mineral density as the host bone; in the autogenous bone graft group, the block of the X-ray in the transplant area has further strengthen, the mineral density of the transplant area is slightly lower than the surrounding tissue. Blank control group has no X-ray block, a small amount of sclerotin formatted around the avascular necrosis of the bone defect,the results of the histology observations is12weeks after the operation, tissue engineered bone formatted fibrous bone, a large number of angiogenesis:autogenous bone graft group formatted fibrous bone, new blood vessels significantly increased. Therefore, rabbit bone marrow stromal cells and tissue engineering bone constructed of nanometer hydroxyapatite/poly lactic acid has good repair function of the bone which is the similar ability of repair avascular necrosis of the bone defect as the autogenous bone graft.[Conclusion]:This study suggests that the tissue engineered bone which implant in the rabbit avascular necrosis of the bone defect have finished the bone and repair the defect after12weeks, indicates the Nanometer Hydroxyapatite/polylactic acid (n-HA/PLA) material has the good tissue compatibility. Compared the process of osteogenesis and revascularization of the the experimental group and control group, the results shown that as time pass, the two tissue compatibility and and revascularization degree increased gradually, but at different time, the experimental group were higher than those in the control group, there are great different difference between those two group. Therefore, rabbit bone marrow stromal cells and tissue engineering bone constructed of nanometer hydroxyapatite/poly lactic acid has good repair function of the bone which is the similar ability of repair avascular necrosis of the bone defect as the autogenous bone graft.