Objective To observe the effect of "knot-loosing method" of acupotomy on morphological changes in knee osteoarthritis(KOA) rabbits

so as to provide experimental basis for clinical acupotomy treatment of KOA. Methods Male New Zealand rabbits were randomly divided into blank control

model and acupotomy groups

with 8 rabbits in each group. By using the modified Videman method

the left hindlimb was immobilized for 6 weeks with a plaster cast to replicate the KOA model. The knot-loosing manipulation of acupotomy was applied to "Hedingci"(located at the attachment of the positive upper margin of the quadriceps tendon and the patella)

"Binneixia"(at "Neixiyan" [EX-LE4]

the medial side of ligamentum patella)

"Binwaixia"(at "Waixiyan" [ST35]

the lateral side of patellar ligament)

"Chengfeijian"(at the lateral collateral ligament of the knee in the la-teral joint space)

"Weiyangci"(at the medial margin of the biceps femoris and the lateral side of the transverse striation)

and "Yinlingci"(at the end-point of the medial tibia of the goose foot tendon)

respectively

once a week for 4 times. One week after the last intervention

the left knee joint dysfunction severity(pain

maximum walking distance

and some activities of daily living) was evaluated by using modified Lequesne Index score. X-ray and magnetic resonance imaging(MRI)examinations were conducted to assess the articular space size

effusion and cartilage smoothness of the left knee for which the MRI Osteoarthritis Knee Score(MOAKS) was given according to their severity. The histopathologic changes of the cartilage of the left knee were observed by Hematoxylin-eosin(H.E.) staining and light microscope

which Mankin score was given. In addition

the surface of the cartilage was also examined by macroscopic observation. Results(1)Following modeling

the Lequesne Index score

MOAKS

macroscopic observation score and Mankin score were significantly increased in the model group(P<0.05). X-ray and MRI imaging showed a narrower joint space

more effusion

rough cartilage surface; and H.E. staining displayed rough cartilage surface

and disordered arrangement and occasional clusters of the chondrocytes in the left knee joint.(2)In comparison with the blank control group

the Lequesne Index

MOAKS

macroscopic observation and Mankin scores were significantly down-regulated in the acupo-tomy group(P<0.05). The abovementioned injury changes shown by X-ray

MRI

macroscopic and microscopic observations were relatively milder in the acupotomy group. Conclusion Acupotomy loosing based on the "Jingjin theory" of traditional Chinese medicine can effectively improve the motor ability of knee joint and repair pathological changes of the cartilage in KOA rabbits.