Experimental Study Of The Inhibitory Effect Of BFGF On Heterotopic Ossification

Objective:Heterotopic ossification(HO)is the abnormal formation of true bone within extraskeletal soft tissues.It can be found more frequently in those tissues around the joints.With the application of total hip replacement and open abduction and inner fixation for fracture of acetabulum since the 1970's, the rate of HO around the hip joint is growing.So the new mothod for prevetion of HO is more concemed than the past. Basic fibroblast growth factor(bFGF)demonstrate inhibitory effect of bFGF on cartilage and bone differentiation in vitro.Through the establish of animal model,we use different ways to intervene the formation of HO,such as indomethacin or bFGF.So it can offer helpful experiences and methods for curing patiens with HO.Methods:48 rabbits were used to establish animal model of heterotopic ossification.And the rabbits were randomly divided into 4 groups.One group was considered as control group without any measures.The other groups were treated respectively with local administration of bFGF,oral administration of indomethacin,both local administration of bFGF and oral administration of indomethacin.X-ray radiographs of the hindlimbs were taken at 4,8,12 weeks after operation.Then according to the DeLee typing,to assess the degree of heterotopic bone formation.At the end of the experiment,we use Hematoxylin and eosin staining was carried out for histological analysis.Results:(1)Radiological analysis:X-ray radiographs of the hindlimbs were taken at 4,8,12 weeks after operation.Then assess the degree of heterotopic bone formation.The rates of heterotopic bone formation for the control group were respectively 41.7%,66.7%,83.3%at the 4th,8th and 12th weeks after operation.Compared with the control group,the rate which was treated with oral administration of indomethacin experienced a significant decrease in the rate of heterotopic bone formation(from 36.3%to 83.3%,P＜0.05);the rate which was treated with local administration of bFGF experienced a significant decrease in the rate of heterotopic bone formation(from 33.3%to 83.3%,P＜0.05);the rate which was treated with both local administration of bFGF and oral administration of indomethacin experienced a significant decrease in the rate of heterotopic bone formation(from 25.0%to 83.3%,P＜0.05).(2)Histological analysis:Hematoxylin and eosin staining was carried out.We can learn from the photomicrographs of the control group that the heterotopic bone contains osteoblasts attached to lamellar bon e.On the contrary,more fibrous tissue can be found from the the photomicrographs of the group which takes the bFGF.Conclusion:The group with local administration of bFGF can effectively inhibit the formation of heterotopic bone.The effect is equal to the group which used oral administration of indomethacin.But the synergistic effect between local administration of bFGF and oral administration of indomethacin can not be learned,mucosal erosion or ulcer in the rabbits'stomach was found which take the indomethacin.On the contrary,we can not learn from the group which used bFGF.In all,the local use of bFGF is an effective way to prevent the HO,but further research is always needed before it used as a clinical durg for HO.