Objective To observe the effect of acupotomy(needle-knife)therapy on local pathological changes and cartilage-mechanics related protein expression in rabbits with knee osteoarthritis(KOA)so as to study its mechanisms underlying improving KOA.Methods Forty New Zealand rabbits were randomly divided into normal control group

model group

acupotomy group

and electroacupuncture(EA)group(n=10in each group).The KOA model was established by immobilization of the left knee-joint(modified Videman method)for 6weeks.After modeling

acupotomy relaxing was applied to the lateral collateral ligament and patellar ligament of the left knee-joint

once a week for 3times

and EA(2Hz/100 Hz

3mA)was applied to the left"Yanglingquan"(GB 34)

"Yinlingquan"(SP 9)

"Neixiyan"(EX-LE 4)and"Waixiyan"(ST 35)for 20 min

3times a week for three weeks.The expression levels of Integrinβ1

type II collagen(Col-Ⅱ)

matrix metalloproteinase(MMP)-3and Aggrecan proteins of the cartilage tissue of the left femoral medial and external condyles were observed by Western blot.Pathological changes of the knee-joint by X-ray scanning and those of the femoral condyle tissue were evaluated by Mankin's scores under light microscope after H.E.staining.Results X-ray showed successful modeling

and pathological changes of the articular cartilage belonged to the early and moderate lesion of knee osteoarthritis.The Mankin's score was significantly higher in the model group than in the control group(P<0.01)

and after the treatment

the Mankin's scores were significantly decreased in the acupotomy group(P<0.01)

rather than in the EA group(P>0.05).The results of Western blot showed that after modeling

the expression levels of Integrinβ1

Col-Ⅱ and Aggrecan proteins of the femoral articular cartilage were considerably decreased(P<0.01)

while that of MMP-3protein was significantly increased(P<0.01).Compared with the model group

the decreased expression levels of Integrinβ1

Col-Ⅱand Aggrecan proteins in the acupotomy group and Integrinβ1protein in the EA group were notably up-regulated(P<0.01

P<0.05)

and MMP-3expression in the acupotomy group was significantly down-regulated(P<0.01).No significant changes were found in the EA group in the expression levels of Col-Ⅱ

Aggrecan and MMP-3proteins compared with the model group(P>0.05).Conclusion Acupotomy intervention can relieve KOA-induced injury of the kneejoint in KOA rats

which is associated with its actions in raising expression levels of Integrinβ1

Col-Ⅱ and Aggrecan proteins and in lowering the expression of MMP-3proteins in the articular cartilage

probably by adjusting the mechanics-related signal pathway of the articular chondrocytes.