Objective To sum up the recent progress of common bone graft substitute and to forecast the possible directions for further research. Methods Recent original articles about investigation and appl ication for bone graft substitute were extensively reviewed. Several common bone graft substitutes were selected and expounded in different categories. Results Bone graft was an essential treatment in order to provide structural support, fill bone cavity and promote bone defect heal ing. The gold standard for bone graft was autograft which is subject to many restrictions. In recent years, theresearch and development of bone graft substitute have received publ ic attention. A very great progress has been made in the research and appl ication of allograft bones, synthetic bones and engineered bones, and some research results have been put into use for real products. Conclusion There still exist many problems in present bone graft substitutes. Combining various biomaterials and using the specific processing technology to develop a biomaterial which has the similar mechanical and chemical properties and physical structures to autograft so as to promote bone defect heal ing is the direction for future research.
Objective To comprehend the pathological features and possible pathogenesis of avascular necrosis of the femoral head (ANFH) by morphology and immunohistochemical observation of osterix (OSX) and adiponectin through in vitro traumatic and non-traumatic ANFH specimens, so as to provide a theoretical basis for cl inical treatment. Methods Sixty-six ANFH specimens were collected from 66 cl inical cases undergoing hip replacement surgery. Twenty-four cases of traumatic ANFH (group A) included 17 males and 7 females, aged 21 to 70 years with an average of 56.5 years; 23 cases of steroid-induced ANFH (group B) included 16 males and 7 females, aged 56 to 72 years with an average of 61 years; and 19 cases of alcohol ic ANFH (group C) were males, aged 55 to 67 years with an average of 58.5 years. Bone tissue was got from weight-bearing and non-weight-bearing area of the femoral head respectively. The basic pathological changes was observed by HE staining under the optical microscope, and the percentage of empty bone lacuna and the percentage of trabecular bone area were calculated. The morphological changes of ANFH in different groups were observedby scanning electron microscope (SEM). OSX and adiponectin expression were detected by immunohistochemical technique. Results Gross of the femoral head surface in each group was rough, collapse, articular cartilage loss, osteophyte formation; cross section: dark red in group A, and yellow in groups B and C. HE staining showed that weight-bearing area of ANFH have similar morphological features in three groups. In non-weight-bearing area of groups B and C, the fat cells in bone marrow markedly increased and were hypertrophic; however there were more fibrous tissue in group A. There were statistically significant differences (P lt; 0.001) in the percentage of empty bone lacuna of the weight-bearing and non-weight-bearing area among three groups. There were no statistically significant differences (P gt; 0.05) in the percentage of trabecular bone area among three groups. The SEM observation showed that three groups had similar pathological changes. Brown granules for OSX and adiponectin positive substance were mainly located in the osteoblast of bone marrow of the femoral head. There was statistically significant difference (P lt; 0.05) in the average absorbency (A) value of OSX between group A and groups B, C, but there was no statistically significant difference (P gt; 0.05) between groups B and C. While there was no statistically significant difference (P gt; 0.05) in the A value of adiponectin among three groups. Conclusion Hormones and alcohol necrosis have more obviously fatty degeneration, but the repair capacity of traumatic femoral head necrosis is ber than that of hormones and alcohol necrosis. Alcohol and hormones have inhibitory action on the OSX-mediated osteogenic differentiation. Hormones and alcohol may not affect osteoblast expressing adiponectin and its receptors.