Acupotomy inhibits aberrant formation of subchondral bone through regulating osteoprotegerin/receptor activator of nuclear factor-κB ligand pathway in rabbits with knee osteoarthritis induced by modified Videman method

OBJECTIVE:To investigate the effects of acupotomy on inhibiting abnormal formation of subchondral bone in rabbits with knee osteoarthritis(KOA).METHODS:A total of 24 New Zealand rabbits were randomly divided into four groups of 6 rabbits each[control,model,electroacupuncture(EA)and acupotomy].Eighteen KOA model rabbits were established using a modified Videman method.Rabbits in EA and acupotomy groups received the intervention for 3 weeks.Then,the cartilage and subchondral bone unit were obtained and the histomorphological changes were recorded.Osteoprotegerin(OPG)and receptor activator of nuclear factor-κB ligand(RANKL)in subchondral bone were evaluated by Western blotting,real-time polymerase chain reaction and immunohistochemistry.RESULTS:Compared with the model group,both the acupotomy and EA groups showed a significant decrease in the Lequesne index(both P<0.01)and Mankin score(P<0.01,<0.05).In addition,both EA and acupotomy groups had a higher expression of total articular cartilage(TAC)(P<0.05,<0.01)and lower expression of articular calcified cartilage(ACC)/TAC(P<0.05,<0.05)compared with the model group.The thickness of the subchondral bone plate in EA and acupotomy groups were decreased(both P<0.01)compared to the model group.Moreover,trabecular bone volume(BV/TV),protein and relative expression of OPG and the ratio of OPG/RANKL in the subchondral bone of acupotomy group were decreased statistically significant,while these parameters were not significantly changed in the EA group compared with the model group.CONCLUSIONS:In the rabbit model of KOA,acupotomy inhibits aberrant formation of subchondral bone by suppressing OPG/RANKL ratio as a potential therapy for KOA.