[Effects of "knot-loosing" of acupotomy on motor function and morphological changes of knee joint in knee osteoarthritis rabbits].

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: ①Following 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. ②In 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.