Temporal and spatial expression of BMP-2 in sub-chondral bone of necrotic femoral heads in rabbits by use of extracorporeal shock waves.
OBJECTIVE
Extracorporeal shock wave treatment has been used successfully for the treatment of avascular necrosis of the femoral head. The pathway of biological events by which this is accomplished has not been fully elucidated. BMP-2 is a key mediator of bone development and repair, and is uniquely required for bone formation. We therefore examined the effect of extracorporeal shock waves on induction of BMP-2 in necrotic femoral heads.


METHODS
Femoral head necrosis was induced in rabbits by treatment with methylprednisolone and lipopolysaccharide. BMP-2 expression was assessed by immunohistochemistry, quantitative real-time PCR, and western blot analysis. Histomorphometric analysis was performed to evaluate the rate of bone formation in femoral heads treated with extracorporeal shock waves.


RESULTS
Extracorporeal shock wave treatment was associated with a significant increase in expression of BMP-2 protein and mRNA in the subchondral bone of the necrotic femoral heads. Moreover, the most intensive immunostaining of BMP-2 was observed in the proliferative zone above the necrotic zone. Histomorphometric analysis showed that extracorporeal shock wave treatment significantly increased the rate of bone formation in the subchondral bone.


CONCLUSIONS
We conclude that extracorporeal shock wave treatment significantly upregulates the expression of BMP-2 in necrotic femoral heads. The process of repair of femoral head necrosis is accelerated by the use of extracorporeal shock waves.
Ma
Huan-Zhi
HZ
Department of Orthopedic Surgery, Shanghai Sixth People's Hospital, Shanghai Jiaotong University, Shanghai, China.
Zeng
Bing-Fang
BF
Li
Xiao-Lin
XL
Chai
Yi-Min
YM
D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000096:biosynthesis*; D005270:Femur Head / Q000378:metabolism; D005271:Femur Head Necrosis / Q000378:metabolism* / Q000628:therapy; D019220:High-Energy Shock Waves / Q000627:therapeutic use*; D006801:Humans; D007150:Immunohistochemistry; D010012:Osteogenesis / Q000502:physiology; D011817:Rabbits; D016212:Transforming Growth Factor beta / Q000096:biosynthesis*
C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D016212:Transforming Growth Factor beta