| Objectives To investigate the feasibility of establishing a PFJOA model by inducing a patella baja in the right knee joint of the female SD rats by patellar ligament shortening(PLS).At the same time,bilateral oophorectomy(OVX)was established to establish OP rat model to study the effect of OP on PFJOA.The effects of SCT on the articular cartilage and subchondral bone microstructure of OP and PFJOA rats were studied by salmon calcitonin(SCT).Methods Fifty three-month-old SD female rats were purchased from professional laboratory animals,and then randomly divided into five groups,10 in each group: sham operation group(Sham group),OVX surgery group(OVX group),and PLS operation group(PLS group),PLS+OVX surgery group(O+P group)and PLS+OVX+SCT group(SCT group).Ovariectomy in the OVX group,ligament shortening in the PLS group,ovarian resection and patellar ligament shortening in the O+P group,and salmon calcitonin treatment in the SCT group after OVX and PLS surgery,Sham group Then only cut the skin and suture after exposure.Postoperative treatment: SCT rats were given subcutaneous SCT at a dose of 16 IU/kg every other day.The other 4 groups were given subcutaneous injection of the same amount of normal saline every other day.Five groups of rats were sacrificed by euthanasia after 10 weeks of administration,and then X-ray films were taken on the right hind limbs of 5 groups of SD rats,and the Insall-Salvati index was measured and recorded.Then,the right knee joint specimens of the rats were collected.In the removed specimens,the knee joint specimens of five rats were randomly selected from each group,and then the knee joints were dissected,and the specimens of the patellofemoral joints were photographed and observed.The general shape of the femoral joint was generally scored.All specimens were then fixed with a pre-formulated 4% formaldehyde solution.After 72 hours,micro-CT was used for the imaging test,and finally all the large mouse was thoroughly decalcified for 12 weeks.The calciumdepleted specimens were embedded in paraffin and sliced with a microtome to detect changes in the subchondral bone and cartilage of the patellofemoral joint: 1 row of toluidine blue staining,and then the tomidine blue-stained section image was collected using an experimental acquisition image microscope.And evaluated using the OARSI score to assess the degeneration of cartilage;2 by immunohistochemical staining of the destructive protein metalloproteinase-4(ADAMTS-4)with platelet thrombin-sensitive protein-like motif in articular cartilage The expression of aggrecan(AGG)was analyzed and analyzed,and then the optical density value of the immunohistochemical staining was measured by Image-Pro Plus 6.0 software.Finally,the corresponding data of each group were collected for relevant statistical analysis.Results 1 The gross morphological scores showed that the gross morphology scores were significantly higher in the PLS group and the O+P group than in the Sham group(p<0.05).The O+P group was significantly higher than the OVX group.(p<0.05);the SCT group had a lower overall score than the O+P group,but the difference was not statistically significant(p<0.05).2 Insall-Salvati index: Insal1-Salvati index was significantly lower in the PLS group,O+P group and SCT group compared with the Sham group and the OVX group(p<0.05),suggesting that the patellar ligament shortening can cause the lower tibia.3 Toluidine blue OARSI histological scores showed that the histological scores of PLS group and O+P group were significantly higher than that of Sham group(p<0.05);O+P group score was significantly higher than OVX group(p<0.05);SCT group Compared with the O+P group,the histological score decreased,but the difference was not statistically significant(p<0.05).4 Immunohistochemical staining: Compared with Sham group,the expression of AGG in cartilage of PLS group and O+P group was significantly decreased(p<0.05),and the expression of ADAMTS-4 was significantly increased(p<0.05);compared with OVX group The expression of AGG in the cartilage of O+P group was significantly decreased(p<0.05),and the expression of ADAMTS-4 was significantly increased(p<0.05).Compared with the PLS group,the expression of ADAMTS-4 was significantly increased in the O+P group(P<0.05).<0.05);Compared with the O+P group,the expression of AGG was significantly increased in the SCT group(p<0.05),and the expression of ADAMTS-4 was significantly decreased(p<0.05);5 Micro-CT test results: OVX group,PLS The amount of bone loss in the subchondral microstructure of the rats in the O+P group decreased,the number of trabecular bone decreased,the thickness became thinner,and the trabecular bone spacing increased.The severity was most obvious in the O+P group.After the intervention in the SCT group,the amount of subchondral bone increased and the microstructure was significantly improved.Compared with Sham group,BMD,BV/TV,Tb.N and Tb.Th were significantly lower in PLS group and O+P group(p<0.05),Tb.Pf and SMI were significantly increased(p<0.05);OVX group Compared with Sham group,BMD,BV/TV,Tb.N decreased significantly(p<0.05),and Tb.Pf increased significantly(p<0.05).O+P group compared with PLS group,BMD,BV/ TV and Tb.N were significantly decreased(p<0.05),and Tb.Pf and SMI were significantly increased(p<0.05).Compared with O+P group,SCT group was BMD,BV/TV,Tb.N and Tb.Th was significantly increased(p<0.05),and Tb.Pf and SMI were significantly decreased(p<0.05).Conclusions 1Patellar ligament shortening can change the mechanical anatomy of the patellofemoral joint,causing abnormal changes of articular cartilage and subchondral microstructure,and successfully establish a rat model of patellofemoral arthritis;2 estrogen decline after ovariectomy can be successfully induced A rat model of osteoporosis,and osteoporosis caused by estrogen deficiency has an aggravating effect on patellofemoral arthritis.3 After treatment with salmon calcitonin,it can delay the damage of patellofemoral articular cartilage in osteoporosis and patellofemoral arthritis rats,and improve the substructure of subchondral bone.Figure8;Table3;Reference 118... |
