| IntroductionOsteoporosis is one of the metabolic disease of the whole body,with bone microstructural failure,reduced osseous tissue and bone trabecula.The bones of the patients who suffered from osteoporosis become even thinner, brittle and easily broken. It will a long time for the osteoporosis patients with a fracture to recover. Many of the patients can't recover completely and happen fractures more easily.So far,the researchers have found that many factors play key roles in the process of osteoporotic fracture healing.Transforming growth factor(TGF-β) is one of these factors,which promotes fracture healing. But most researches of the TGF-P expression in the process of osteoporotic fracture healing depended on animal experiments,few researches depended on human tissues.To observe transform growth factor-P(TGF-β) expression and its roles in the fracture patients with or without osteoporotic in different period of fracture healing.SubjectiveFrom May,2008 to Feb,2010,40 cases with proximal femoral fractures.All the cases come from Orthopaedic Hospital of Shenyang City. Range,65-75 years,17 males and 23 females.10 cases were taken as the control group,including 6 males and 4 females.30 cases with osteoporosis patients,including 11 males and 19 females.40 patients with neck of femur and femur intertrochanteric fracture were selected. These patients were operated during 1-7 days,8-14days,15-21 days and 22-28days after fracture, respectively.30 patients were suffering from osteoporosis. Other 10 cases were as control group.MethodsThe local callus of the fracture were fixed, decalcificated, embedded and sliced. The sections were dealed with HE staining and TGF-P immunohistochemistry staining. Saving the picture and the data was available to statistical analysis by statistical software.Results1.Histology:In the process of fracture healing,although more cartilaginous callus are formed,the transition from cartilaginous callus to bony callus is delayed,which extends the healing procedure.Furthermore,the mature bone trabecula structures are loose and the quality of the bony callus is worse.2.TGF-P was expressoin in the cytoplasm of mesenchymal cells,osteoblasts and chondrocytes.The highest TGF-P expression was found in the period of 8-14 and 15-21 days after fracture and the differencewas significant respectively(P<0.05).In other periods,the TGF-βexpression was decreased in different extent, but there was no significant difference between the osteoporosis group and the control group(P>0.05).DiscussionWith the increase of aging population in China, the rate of incidence of osteoporosis is increasing.In recent years,many researchers have confirmed that bone fracture healing is delayed by osteoporosis.Osteoporosis is associated with increased cartilaginous callus,decreased bone density and biological function. In this study,on one hand,during the process of fracture healing,although more cartilaginous callus are formed,the transition from cartilaginous callus to bony callus is delayed,which extends the healing procedure.On the other hand, the mature bone trabecula structures are loose and the quality of the bony callus is worse.Osteoinduction and many growth factors play key roles in the process of bone fracture healing.Transforming growth factor(TGF-β) is one of these factors,which control many kind of cells in the bone marrow,such as mesenchymal cells,osteoblasts,chondrocytes,osteoclasts and so on.Its role on the cells depended on many factors, including cell type,differentiation, growth condition,exist of other growth factors,the TGF-βaction concentration and time.Now it have been confirmed that TGF-βis a strong chemotatic factor,it can stimulate mesenchymal cells to differentiation as chondrocytes.At the same time,TGF-p can promote osteoblasts proliferation and bone callus calcification.The local releasing TGF-P adjusts bone absorption and formation in bone callus remodeling. In different peroids of fracture healing,expression of TGF-βgene are dynamic and different.In our study,TGF-βwas expressoin in the cytoplasm of mesenchymal cells, osteoblasts and chondrocytes.The highest TGF-βexpression was found in the period of 8-14 and 15-21 days after fracture and the difference was significant respectively.In other periods, the TGF-βexpression was decreased in different extent, but there was no significant difference between the osteoporosis group and the control group.The time of cartilage and bone formation in cartilage were both extended.In a word,TGF-βis a very important factor that is correlated with cell proliferation,differentiation and extracellular matrix synthesis.Osteoporosis can affect TGF-βexpression of different cells. It can depress the function of osteoblasts especially, and decrease the TGF-βexpression, which is associated with fracture healing prolong. Further researches of the mechanism of TGF-βin adjusting bone physiology and healing are very importmant, and they will help the doctors to improve the clinical therapy of osteoporosis fracture.Conclusions1. In the process of osteoporosis fracture healing, the transition from cartilaginous callus to bony callus is delayed,which extends the healing procedure.The quality of the bony callus is worse.2. In the process of osteoporosis fracture healing, the poisitive rate of TGF-βexpression was significantly lower than that of control group.TGF-βmay play key roles in this process and the decreased TGF-βexpression in local callus is correlated with delayed fracture healing.
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