Influence Of Extracorporeal Shock Wave On Proliferation Of Osteoblast In Rabbits

Objective: To inevestigate the effect of extracorperal shock waves on osteeblast proliferationand bone formation in avascular necrosis of femoral heads of rabbits．Methords:36New Zealand white rabbits， weighted from2.5to3.5， Were givenmethylprednisolone and lipopelysaccharide for establishing avagcular necrosis models offemoral head．After mading models successfully, randomly dividing rabbits into two groups,Group A is the control group, Group B is ESW experience group and the time of ESW treatmentis at the beginning of the sixth week. Hematoxylin-eosin staining was used to observe thehistological changes of avascular necrosis of femoral head at week4，8and12after treatment,The percentage of empty lacunae and the osteoblast number were used to evaluate the boneformation．Results:1.General observation showing:the femoral head of experimental group in shape outline,smoothness, colour and lustre, bone crunchy degree, coronal, coronal plane change after dividingcoronally showed improvement with different degree compared with the same period controlgroup, especially the femoral head of experimental group showed apparent change at12weeksafter ESW intervention2.Hematoxylin-eosin staining showing： a small amount of spindle osteoblasts can beobserved in bone trabeculaes around and protruding bone cells can be found in the femoral headof experimental groups at4weeks after ESW intervention, whereas in the controlgroups,attenuate and sparse bone trabeculaes, large areas of empty lacunaes and pyknoticosteocyte nucleis can be observed in the femoral head. At eight weeks After ESW intervention，single row separate arrangement of visible osteoblasts surrounding bone trabeculae, childishbone cells in bone trabecular can be seen, whereas in the control group， visible part of thefracture bone trabeculars, empty bone lacunaes and pyknotic osteocyte nucleis in bone trabecularcan all be found, a lot of fat cells becomed Volume Increases and accumulation in aroundintramedullary. At12weeks After ESW intervention, obviously thickening and osteoblastssurrounding bone trabeculaes can be observed, a lot of new bone cells in bone trabeculaes, emptybone lacunaes can rare be seen in the femoral head of experimental group. whereas in the controlgroup,most bone trabeculaes were atrophy、thinner and fracture，a lot of empty bone lacunaescan be found.3.The contrast of osteeblast number and the percentage of empty bone lacunaes ofexperimental group and control group： In ESW experience group,Ostcoblast number started toincrease at week4，peaked at week8and persisted until week12．But osteeblast number werescarce in control group．At week8and12after treatment，Ostcoblast number in experience group significantly hisher than in control group(P<005or P<0.01)．At week8and12aftertreatment，the percentage of empty lacunae in experience group significantly lower than incontrol group(P<0.05or P<0.01)．Conclusion: Extracorporcal shock waves can Induction and strengthen osteeblast proliferationand promote new bone formation in the avascular necrosis of rabbit femoral head．...