| Objectives This study aims to explore the feasibility of the adult New Zealand white rabbits with patellar ligament shortening to imitate human patella baja surgery model,manufactur patellofemoral arthritis mode caused by patella baja;and early application of hyaluronic acid(HA)to intervene the patellofemoral arthritis model,study on hyaluronic acid′s effects on femoral condyle.Methods Twenty-four 24-week-old New Zealand rabbits were divided into 3 groups,8 rabbits in each group;normal control group(control),PL group(Patellar ligament,PL)and HA group(HA),normal control group without any surgical operation and drug intervention,the patellar tendon shortening group in after adaptive breeding for one week,start the implementation on the left hind of patellar ligament shortening,HA group also shorted the patellar tendon of the left hind limb,knee intra-articular injection of hyaluronic acid 2ml immediately after surgery,once a week.The experimental animals were euthanized after 8 weeks of administration.Radiographs of 3 groups of New Zealand white rabbits left hind to measure Insall-Salvati index,after knee joint anatomy,take photos of the specimens to observe patellofemoral joint general morphology,score from the articular surface of the femoral condyles articular surface degree of wear and color,and then the left knee was harvested and fixed in 4% formaldehyde.The left knee was decalcified for 8 weeks.Then all specimen were paraffin-embedded and sectioned.The paraffin-embedded sections were stained with toluidine blue and COL-II,MMP-9,Caspase-3 immunohistochemical staining respectively.Toluidine blue stained sections were analyzed according to OARSI histological score.The expression level of COL-II,MMP-9,Caspase-3 were assessed respectively by immunoradioactive score.The data of each group were analyzed statistically.the OARSI histological scoring guide on the formation of articular cartilage,cartilage fracture,cartilage cells,cartilage cell cluster hyperplasia score were detected.PL group were compared with control group to verify the modeling success,and HA group were compared with PL group to observe the effect of hyaluronic acid on the cartilage of patellofemoral arthritis.The inhibition degree of hyaluronic acid on cartilage degeneration was compared between the HA group and the control group.Results 1 Insall-Salvati index: the Insal1-Salvati index of the PL group and HA group was significantly lower than that of the normal control group,indicating that patella ligament shortening can cause low patella.2 Gross morphological score: the PL group was compared with the normal control group,the score was higher,and the HA group was compared with the PL group,the score was lower.There was no significant difference in the score between the HA group and the control group(P>0.05).3 OARSI score: in toluidine blue staining,the PL group compared with normal control group,the score increased;HA group compared with the PL group,score decreased;The score of the HA group was significantly higher than that of the control group(P<0.05).4 Immunohistochemical staining: PL group compared with normal control group and HA group,the expression of COL-II was significantly decreased(P<0.05);There was no significant difference in COL-II expression between the HA group and the control group(P>0.05).PL group compared with normal control group and HA group,comparison between the HA group and the control group,the expression of Caspase-3 was significantly increased(P<0.05);PL group compared with normal control group and HA group,comparison between the HA group and the control group,the expression of MMP-9 was significantly increased(P<0.05).Conclusions 1 Rabbit patellar ligament shortening resulted in the formation of low patella and degeneration of femoral condyle cartilage,which proved that patellar ligament shortening is an effective animal model to simulate the occurrence and development of patellofemoral arthritis after low patella baja.2 Hyaluronic acid injection within the knee for 8 weeks can delay patellar arthritis cartilage degeneration after the patella baja,and may delay the disease progression of patellofemoral arthritis. |
PDF Full Text Request