Evaluation Of The Clinical Effect Of Ectopic Fostering Replantation Of Contaminated Bone In Dogs

In recent years,the number of open fractures in pets caused by car accidents,falling buildings and other accidents has been increasing.The incidence of bone infections in these cases is extremely high and it is difficult to treat.Although debridement can effectively prevent bone infection,the large amount of free contaminated bone removed during debridement has brought new problems to bone defects.There are many methods for clinically treating bone defects,but they all neglect the reuse of freely contaminated bones,resulting in great waste.Therefore,this experiment established a model of canine tibia bone defect,and explored the therapeutic effect of repairing bone defects caused by open fracture after subcutaneous embedding and revascularization of canine bone.In this experiment,12 healthy adult dogs were selected and a 15 mm long free bone in the middle part of the right forelimb was taken to establish a canine tibia bone defect model.After 4weeks and 8 weeks of overall observation and Radiography examination,the canine bone defect model was determined to be successful and can be used in subsequent experiments.Twelve successful dogs were randomly divided into an embedding group and a frozen group.The intercepted free bone was placed in the external soil for 1 h.After the bone was retrieved,it was immersed in a 10% povidone iodine solution for 5 min,then rinsed with physiological saline and dried naturally.In this experiment,different methods were used to treat the free bones of the two groups.The embedding group was embedded in the saphenous vein.The frozen group was placed at-80°C for deep cryopreservation.After 8 weeks,the bone fragments were removed and planted back.The healing of the two groups was evaluated by the gross morphology of the bone,Radiography,histology,Lane-Sandhu bone formation scoring standard,and bone biochemical markers within 12 weeks after implantation.Gross morphology observation showed that at the 12 th week after bone defect repair,compared with the frozen group,the osteophytes of the dogs in the embedding group were well shaped,and the boundary between the graft and the autogenous bone disappeared.Radiography examination revealed that the cortical part of the embedding group was completely connected compared with the frozen group.The results of histological examination showed that compared with the frozen group,the bone plate of the embedding group was arranged regularly,and mostof the bone connections were formed.The Lane-Sandhu Radiography score and the histological bone formation score of the embedding group were superior to those of the frozen group,and the difference was statistically significant(P<0.05).Bone biochemical markers showed that Bone specific alkaline phosphatase(BSAP)and Osteocalcin(OC)were significantly higher in the sixth week than in the frozen group(P<0.05),C-terminal propeptide of type I procollagen(PICP)and C-terminal telopeptide of type I collagen(CTX)were significantly higher in the second week than in the frozen group(P<0.05),and N-terminal propeptide of type I procollagen(PINP)was significantly higher in the second and eighth weeks than in the frozen group(P<0.05).Group(P<0.05).In summary,a 15 mm long bone segment in the middle of the humerus can be used to establish a canine tibia bone defect model.Compared with the low temperature group,the bone healing,bone cell activity and bone formation status of the embedding group were better,the fracture healing time was significantly shortened,and the contaminated subcutaneous embedding and revascularization could be used for the bone defect caused by the clinical open fracture of pets.treatment.