The Effect Of Alendronate On Experimental Osteoarthritis Of Lumbar Facet Joints In Rats

Objectives This study's purpose was to research the feasibility of intraarticular injection of type ? collagenase into male SD rat lumbar facet joints to induce lumbar facet joint osteoarthritis(FJOA).With the early administration of alendronate sodium(ALN)in this lumbar FJOA model,to explore the effects of ALN on FJ degeneration.Methods Thirty 3-month-old male SD rats were randomly assigned into the sham group(Sham,n=10),the collagenase type ?(C?)injection group(C? group,n=10)and the ALN group(ALN,n=10).C? and ALN groups were operated and injected type ? collagenase into lumbar facet joints(FJ)(right L3–4,L4–5,and L5–6 FJs).Sham group rats received the same surgical as the C? rats,but collagenase was not injected into the FJs.ALN was given to the rats in the ALN group at the dose of 70?g/kg/week by hypodermic injection,and the same volume of saline was given to the C? group and the Sham group.All animals were sacrificed at the end point of 8 week of administration.Then all lumbar vertebras were evaluated by Micro-CT.The modified Mankin score was used to evaluate the cartilage degeneration of the FJs after toluidine blue staining.The immunohistochemical staining and IOD score were used to detect the protein expression of Caspase-3 and ADAMTS-4 in the cartilage.The concentration of COMP in serum was measured using an enzyme linked immunosorbent assay(ELISA).Results Micro-CT results showed that the subchondral bone mineral density(BMD),bone volume fraction(BV/TV),and trabecular thickness(Tb.Th)were significantly lower in the C? group than in the Sham group(P<0.05),trabecular bone separation(Tb.Sp)was significantly increased in the C? group than in the Sham group(P<0.05);when using ALN intervention,the BMD,BV/TV,Tb.Th were significantly higher in the ALN group than in the C? group(P<0.05),and Tb.Sp was significantly decreased(P<0.05).The modified Mankin score showed that the C? group score was significantly higher than that of the Sham group(P<0.05),and the ALN group score was significantly lower after drug intervention(P<0.05).The results of immunohistochemistry showed that the IOD value of Caspase-3 and ADAMTS-4 in chondrocytes was significantly increased in C? group compared with Sham group(P<0.05),Compared with C? group,the IOD value of Caspase-3 and ADAMTS-4 in ALN group was significantly reduced(P<0.05).The ELISA results showed that the serum COMP concentration was significantly higher in the C? group than in the Sham group(P<0.05),and the serum COMP concentration was significantly lower in the ALN group than in the C? group(P<0.05).Conclusions Injection of C? into lumbar FJs could establish a rat model of lumbar FJOA and result in the damage to the articular cartilage and subchondral bone in rats.ALN treatment can alleviate that damage of lumbar FJ cartilage and destruction of subchondral bone microstructure induced by C? in rat.Figure8;Table1;Reference 100...